VLBI Software Documentation
Field System
SNAP Commands
W. E. Himwich and N. R. Vandenberg
NVI, Inc./GSFC
Operations Manual
NASA/Goddard Space Flight Center Version 9.3
Space Geodesy Program September 1, 1997
| |
1.0 SNAP Command Syntax |
2.0 On-Line
Help 3.0
SNAP Command Descriptions
This manual contains detailed descriptions of the SNAP commands
available in the Field System. Each command is described on a
separate page. Commands are ordered alphabetically.
Please refer to the SNAP
Language manual for the specifications of the
language itself, including a description of control commands and
general syntax.
The subsections of this first section contain reference
information that applies to many commands.
1.1 Command Descriptions
In this manual, each command is described on a separate page. For
each command, the information is provided:
command - function (equipment)
The command name and a few words that describe its function are
given at the top of each page. If the command is restricted to
certain types of equipment, that information is given in
parentheses. For example, the rec command is
applicable only to VLBA drives, and the title will include the
words (VLBA drive). Most commands have no
restrictions, although they may behave slightly differently for
different equipment. Mark III commands are applicable to Mark IV
unless there is a separate Mark IV command description.
Syntax: command=list of parameters
The command syntax is shown first. The command name and the list
of parameters are shown. The various forms of the command are
described in the Comments section. Any combination of upper case
and lower case letters may be used in typing a command. All
commands are converted to lower case before they are processed.
Response: command/list of response parameters
The response (if any) to the command is given with the list of
parameters appearing in the response. Normally the response to a
command has an identical list of parameters to the command itself,
followed by any monitor parameters. All responses to commands are
displayed in lower case letters only.
Settable parameters:
This part of the page describes each parameter in the "Syntax"
line that can be specified by the operator. The allowable range of
values for each parameter is given. The default value, if any, is
given. A default value is obtained by entering a null for a
particular parameter. The parameter value specified in the
previous issuing of this command may be obtained by entering *
instead of a value. Entering ? as the first
parameter results in a response containing the parameters
specified in the most recent issuance of this command. If any
parameter value is found to be invalid, command interpretation
stops at that point and an error message is generated.
Monitor-only parameters:
Each parameter in the "Response" that does not appear in the
"Syntax" is described in this section. These are parameters that
cannot be specified by the operator, but are monitored or
calculated by the Field System.
Comments:
The final section of the page provides further descriptions of
the way in which the command works. These comments often describe
the algorithm that was used in implementing the command, and
outline specific conditions under which the command should be
used.
The phrase "MAT module functions available" in the comments
section means that the following additional types of parameters
may be used. This is available for those Mark III modules that
have MAT communications.
module=test/reset Issues an MAT reset
to this module only.
module=alarm Resets the alarm on this
module.
The following syntax is valid for those commands which state that
"MCB module functions are available" in the Comments section of
the command description.
module=addr Sends the module its base
address and length. This sets the module's MCB address space.
module=test Checks the module's
address. An error message in response to this command indicates
that the module needs to be sent its address space.
1.4 Module and Detector Mnemonics
The Field System makes use of mnemonics for Mark III, Mark IV,
S2, and VLBA equipment in SNAP commands. Displays of mnemonics are
always two characters, but many forms of module names are allowed
when entering commands. This is a convenience for the operator who
does not have to remember the exact two-character mnemonic.
The SNAP commands that pertain to total power radiometry allow
the operator to specify different detectors in the equipment.
Detectors are specified by using a mnemonic. When the Field System
displays mnemonics they are always two characters, but different
forms of the detector names are allowed when entering commands.
This is a convenience for the operator who does not have to
remember the exact two-character mnemonic.
Valid mnemonics for modules and detectors are listed in the
tables on the following pages.
| Field System Module Mnemonics | ||
| Module | Standard mnemonic | Other allowed mnemonics |
| Mark III modules | ||
| video converters | vn, n=1-f | vcn, n=1-15, 1-f |
| IF distributor | if | ifd |
| formatter | fm | form |
| tape transport | rc | rec, tp, tape |
| high density heads | hd | |
| S/X receiver | rx | |
| IF3 distributor | i3 | if3,ifd3 |
| S2 modules | ||
| tape recorder | rc | rec, tp, tape |
| VLBA modules | ||
| baseband converters | bn, n=1-f | bcn, bbcn, n=1-15, 1-f |
| IF distributor 1, channels A&B | ia | ifa, ifb, ib, ifab |
| IF distributor 2, channels C&D | ic | ifc, ifd, ic, ifcd |
| formatter | fm | form |
| tape recorder | rc | rec, tp, tape |
| Groups of modules | ||
| all modules which have been set up | all | |
| odd video or baseband converters | odd | |
| even video or baseband converters | even | |
| Field System Detector Mnemonics | ||
| Detector | Standard mnemonic | Other allowed mnemonics |
| Mark III detectors | ||
| video converters | vn, n=1-f | vcn, n=1-15,1-f |
| IF distributor channel 1 | i1 | if1 |
| IF distributor channel 2 | i2 | if2 |
| IF3 distributor | i3 | if3 |
| S2 detectors | ||
| none | ||
| VLBA detectors | ||
| baseband converters, USB | nu, n=1-f | bnu,
bcnu, bbcnu,
n=1-15,1-f |
| baseband converters, LSB | nl, n=1-f | bnl,
bcnl, bbcnl,
n=1-15,1-f |
| IF distributor 1, channel A | ia | ifa |
| IF distributor 1, channel B | ib | ifb |
| IF distributor 2, channel C | ic | ifc |
| IF distributor 2, channel D | id | ifd |
| Groups of detectors | ||
| all odd video converters | odd | |
| all even video converters | even | |
| all odd baseband converters USB | oddu | |
| all odd baseband converters LSB | oddl | |
| all even baseband converters USB | evenu | |
| all even baseband converters LSB | evenl | |
2.0 On-Line Help
The entire documentation for each command is available as on-line
help in the Field System. The help command will
display the information for a specified command on the screen
during Field System operations. The information that is listed is
identical to that found on the pages of this manual.
Refer to the page with the help command
description.
3.0 SNAP Command
Descriptions
Syntax: antenna=message,message, ...
Response: antenna/response,response, ...
Settable parameters:
message message to be sent to the antenna in the exact
form required by the pointing software. Each message between
commas will be sent separately.
Monitor-only parameters:
response response of the antenna to the message. This
response is either ack or an error message sent by the antenna.
Syntax: azeloff=az,el
Response: azeloff/az,el
Settable parameters:
az Offset in azimuth, in numeric angle/degrees format. Response is in decimal degrees.
el Offset in elevation, in numeric angle/degrees format.
Response is in decimal degrees.
Monitor-only parameters: none
Comments:
The antenna will move to the offset position when this command is
issued. To return to the on-source position, issue this command
with zero offsets.
Syntax: bbcnn=freq,ifsource,bwu,bwl,avper,gainmode,gainu,gainl
Response: bbcnn/freq,ifsource,bwu,bwl,avper,gainmode,gainu,gainl,
lock,USBpwr,LSBpwr,serno,err
nn is the BBC index number corresponding to its position
in the rack, 01 to 14. Not all
racks have all BBCs.
Settable Parameters:
freq L.O. frequency in MHz, between 450.00 and 1050.00, inclusive. No default. This frequency range is greater than the normal range over which the BBC is specified to lock (500 to 1000 MHz) to allow for testing.
ifsource I.F. input source, one of A, B, C, D. No default.
bwu Bandwidth for USB in MHz. One of 0.0625, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16. Default 2.
bwl Bandwidth for LSB in MHz. One of 0.0625, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16. Default bwu.
avper Averaging period in seconds for TPI. May be 0, 1, 2, 4, 10, 20, 40, or 60 seconds. A value of 0 results in 1/80 sec averaging time. Default 1. The averaging period is common to both upper and lower sideband. The averaging period is synchronous with the 1 pps.
gainmode Gain control mode, either agc or man. Use agc (default) for automatic gain control, man to set a gain value. The gain mode is common to both sidebands.
gainu Gain value for USB. This is a valid parameter only if gainmode is man. May be any value between -99.0 dB and 12.0 dB. Step size is linear in voltage. The actual gain setting is reported as a monitor value. Default is the current USB gain level. This parameter is not implemented.
gainl Gain value for LSB. This is a valid parameter only
if gainmode is man. May be any value
between -99.9 dB and 12.0 dB.
Step size is linear in voltage. The actual gain setting is
reported as a monitor value. Default is the current LSB gain
level. This parameter is not implemented.
Monitor-only Parameters:
lock L.O. lock status, lock or unlock.
USBpwr Power in upper sideband in counts. Range 0 to 65535, nominal operating level is 16000.
LSBpwr Power in lower sideband in counts. Range 0 to 65535, nominal operating level is 16000.
serno Module serial number, decimal.
err Module timing error indication, 1pps or no 1pps.
Comments:
This command sets up the baseband converters in the VLBA rack.
This command is analagous to the Mark III vcnn
commands.
Unlike the output of most other commands which have no embedded
blanks, the output for this command is columized for easy reading
of gains and power levels.
MCB module functions are available. See section 1.0 of this
manual.
The power-up setting for the gain control is manual control with
a value of +6 dB. If the IF level is nominal coming in to the BBC
then the operating level for the AGC is +6 dB. Normal setting
during an experiment is agc.
To hold the gain at a given value, switch to man
gain control. The gain value will stay at the value it had when
the AGC was changed to man. Then use agc
to return to AGC control. This method is used for radiometry by
onoff and fivpt.
On terminals wired like the geodetic racks, the following table
shows which BBCs have which IF inputs available.
| BBC-to-IF input availability | |
| BBC numbers | IF input channels |
| 1, 2 | A, B, C, D |
| 3, 4, 5, 6, 7, 8 | A, C |
| 9, 10, 11, 12, 13, 14 | B, D |
CAUTION: This command does not check whether you have specified a
valid IF source for the BBC.
Syntax: beam1=angle
beam2=angle
beam3=angle
beama=angle
beamb=angle
beamc=angle
beamd=angle
Response: beam1/angle
beam2/angle
beam3/angle
beama/angle
beamb/angle
beamc/angle
beamd/angle
Settable parameters:
angle full-width half maximum beam size, displayed in
decimal degrees of arc.
Monitor-only parameters: none
Comments:
The beam1/2/3
and beama/b/c/d
commands are applicable for Mark III and VLBA systems,
respectively. The command pairs beam1/a,
beam2/b, and beam3/c
are synonomous.
The beam size for the sky frequency for each IF channel may be
specified with these commands. The commands flux1/2/3
and fluxa/b/c/d
use the sizes specified as beam1/2/3
and beama/b/c/d,
respectively, to calculate the apparent flux.
There is no default for the beam size unless the appropriate IF
distributor command (ifd or if3
for Mark III systems, ifab or ifcd
for VLBA systems) and the lo and upconv
commands have been issued. If these commands have been issued,
then the beam size will default to the beam size calculated from
the appropriate LO and upconverter frequencies and the antenna
diameter found in the antenna.ctl control file. The formula is:
beam size (radians) = 1.05*c/(freq*diaman)
Issuing a beamx=...
command will change the calculated values of the fluxx
command to invalid quantities. Reissue a corrrect fluxx=...
command to recalculate fluxes.
Syntax: bit density=bpi
Response: bit density/bpi
Settable parameters:
bpi Bit density in bits per inch.
Monitor-only parameters: none
Comments:
This command specifies the total bit density including all header
and parity bits. The specified bit density and the formatter
set-up determine the default speed for the st
command.
The bit density can be set to any positive value less than 232.
Useful values are 33333 for
Mark III data-replacement format and 34020 for
the VLBA non-data-replacement format. Useful values are 56250
for Mark III data-replacement format and 56700
for the VLBA non-data-replacement format at high density (thin
tape).
When calculating speeds from bit densities it is useful to
remember that for a nominal per track bit rate of 4 MBit/sec, the
Mark III data-replacement format actually generates 4.5 MBit/sec
and the VLBA non-data-replacement format generates 4.536 MBit/sec.
Syntax: break
Response: none
Comments: The currently-executing procedure is stopped after the
current command is finished. The procedure stack is popped to the
next higher level. This is an immediate execution command.
NOTE: This command is not implemented.
Syntax: cable=message
Response: cable/value
Settable parameters:
message ASCII character to be sent to counter.
Monitor-only parameters:
value cable cal reading
Comments:
When issued with no parameters this command sends a request for a
reading to the HPIB counter which is connected to the phase cal
cable measurement system.
The ibad.ctl control file must contain an entry with mnemonic CA
and the device name.
If your counter returns a non-standard response, you can control
the parsing of the response, by placing the uncommented line below
in your stcmd.ctl file:
*command seg sbpa bo eq
cable qkr 13xx 01 FF
Where the value xx is the character position to started decoding
the response at. The normal cable command uses
xx=04. If xx=00, the cable command will try to
find the right place to begin decoding the response at on its own,
looking for the first character that might be part of a number.
You can examine the response from the counter to determine where
to begin the decoding by reading it back with an hpib=ca
command.
Syntax: cal=on/off
Response: none
Settable parameters:
on/off on to turn cal on, off
to turn off. No default.
Monitor-only parameters: none
Comments: This command sets a VHF switch on the HPIB. The ASCII
message is A1 to turn cal on, A2 to turn cal off. The ibad.ctl
control file must contain an entry with the mnemonic CL and the
device name.
Syntax: caltemp1=temp
caltemp2=temp
caltemp3=temp
caltempa=temp
caltempb=temp
caltempc=temp
caltempd=temp
Response: caltemp1/temp
caltemp2/temp
caltemp3/temp
caltempa/temp
caltempb/temp
caltempc/temp
caltempd/temp
Settable parameters:
temp temperature of cal signal, in degrees K.
Monitor-only parameters: none
Comments:
Calibration temperatures, for either Mark III or VLBA systems,
may be specified with the caltemp1/2/3
and caltempa/b/c/d
commands, respectively. The commands tsys1/2/3
and tsysa/b/c/d
use the temperatures specified as caltemp1/2/3
and caltempa/b/c/d
respectively. The command pairs caltemp1/a,
caltemp2/b, and caltemp3/c
are synonomous.
Syntax: check=list
Response: check/list
Settable parameters:
list The list of mnemonics for modules to be checked.
Only mnemonics for the equipment identified in the equip.ctl
control file are valid in this command. Standard module mnemonics
are allowed. If the list of modules to be checked is empty, then
chekr will not check any modules.
Monitor-only parameters: none
Comments:
As modules are set up by SNAP commands, they are automatically
added to the list of modules being checked by chekr. This command
can be used to remove and reinstate modules on the list.
The entire list of modules to be checked may always be specified
by listing the appropriate modules. However, the list of modules
already being checked may also be modified by entering *
as the first parameter, followed by the list of modules to be
added or deleted from the existing list. Deletion is indicated by
a leading minus sign. For example,
check=*,ifd,-rc
will cause the IF distributor to be added to the list of modules
being checked and the tape transport to be removed from the list,
while the check status of all other modules remain unchanged.
If no modules are currently being checked then the word disabled
is displayed.
The displayed list of modules always consists of the standard
2-character mnemonic, i.e. the ones listed on the reference page
at the front of this manual. Station-specific mnemonics may be
used for station-specific modules.
Note: In the current Field System version, for VLBA systems, the
head position is checked but only some of the DAR module and REC
functions are checked.
Syntax: cont
Response: none
Parameters: none
Comments:
This command must be issued after a halt to get
the schedule going again. It has no effect if no halt
was actually issued. This is an immediate execution operator
command.
Syntax: data valid=record,playback
Response: data valid/record,playback
Settable parameters:
record Flag is on (default) or off.
playback Playback enable is use
(default) or ignore.
Monitor-only parameters: None.
Comments:
This command can be used to set and monitor the value of the data
valid and playback enable flags written to the tape.
Syntax: date
Response: date/year,day
Settable parameters: None.
Monitor-only parameters:
year Current year.
day Current day of year.
Comments:
This command is included to allow display of the year and day of
year in the log display window, which normally only shows the
hour, minutes, ands seconds of the log entry time tags. The year
and day of year are guaranteed to be consistent with the displayed
hour, minutes, and seconds of the log entry time-tag for the
response.
Syntax: decode=channel,mode,counter
Response: decode/channel,mode,data
Settable parameters:
channel Channel a (default) or b to be decoded.
mode Type of data to be read. Choices are auxilliary data, synch, crc word, time, data bits, or error counts (default).
counter Error counter control: byte
(default), frame, reset.
Monitor-only parameters:
data Data returned according to mode specified in control command.
err sspppppp (s=synch errors, p=parity errors) Note that monitored error values are error counts, not rates.
syn 8 - character synch word
time two words: ydddhhmm and sssssccc, where ccc = checksum
data three sets of 32 data bits
aux two sets of 8 characters of auxiliary data
crc pass/fail for CRC check
Comments:
MAT module functions available. CRC check is reliable only in
bypass reproduce mode.
Most Mark III drives cannot decode in double speed, so this
command will probably fail in this mode. Old VLBA drives that use
the Mark III bit synchronizer may have this problem also.
Syntax: dqa=duration
Response: dqa/duration,Asampler,Atrack,Aparity,Aresync,Anosync,Acalamp,
Acalphs,Bsampler,Btrack,Bparity,Bresync,Bnosync,Bcalamp,Bcalphs
Settable Parameters:
duration The duration of the analysis in seconds.
Default 1 sec, max 5 seconds.
Set up the command with dqa=duration. Subsequent commands
dqa will make a measurement. For each
measurement, the DQA module is started, allowed to run for duration
and then stopped. The accumulated counters are then read out.
Monitor-only Parameters:
Asampler Sampler for the A channel signal, 0 if unknown or in the form nnsd, nn=baseband converter number, s=sideband u or l, d=data sample bit m or s.
Atrack Track with the A channel signal on it, as set up in the repro command.
Aparity Measured parity error rate for A channel, per Mbyte.
Aresync Measured resync rate for A channel, per Mbyte.
Anosync Measured nosync rate for A channel, per Mbyte.
Acalamp Measured phase calibrator amplitude for A channel, in units of voltage percentage.
Acalphs Measured phase calibrator phase for A channel, degrees.
Bsampler Sampler of the B channel signal, 0 if unknown or in the form nnsd, nn=baseband converter number, s=sideband u or l, d=data sample bit m or s.
Btrack Track with the B channel signal on it, as set up in the repro command.
Bparity Measured parity error rate for B channel, per Mbyte.
Bresync Measured resync rate for B channel, per Mbyte.
Bnosync Measured nosync rate for B channel, per Mbyte.
Bcalamp Measured phase calibrator amplitude for B channel, in units of voltage percentage.
Bcalphs Measured phase calibrator phase for B channel,
degrees.
Comments:
The data quality analyzer (DQA) is a formatter sub-module. It
extracts phase cal and measures parity errors and re-synch rates.
The dqa command is comparable to the Mark III decode
command plus the capabilities of program pcalr. Normally you would
use the check2c1/2 procedures during Field
System operations.
Channels A and B are the recorded tracks as specified in the repro
command. To measure parity errors, the tape should be moving (use
the st command) with record disabled. The phase
cal can be measured in bypass or reproduce mode. For bypass
measurements, the group enables must be turned on with the enable
command, and the general record enable must be turned on with the
st command.
The sampler reported for a track is determined from the set-up of
the cross-point switch by the form command. If
barrel-rolling and/or fan-in or -out are enabled, the displayed
source will be the nominal source for that track, but may not
actually correspond to the data analyzed. If fan-out is being used
in a system with an analog cross-point switch, the reported source
will be zero for tracks beyond the first in a fan-out group.
Phase-cal results will be meaningless for the following cases:
fan-out, fan-in, barrel-rolling enabled, VLBA format, tracks that
contain magnitude bits.
The output from this command is columized for easy reading when
there are no errors, i.e., in bypass mode.
Syntax: echo=set
Response: none
Settable parameters:
set on to turn echo on, off
to turn off (default). Any external communications are echoed in
the log display window.
Monitor-only parameters: none
Comments:
Immediate execution operator command for MAT and/or MCB and/or
RCL communications and, at some stations, antenna communications
also.
For MCB communications, each byte is displayed as
bytes sent to the MCB [nxx]
bytes received from the MCB <nxx>
where n is normally a blank. n is + for the
first byte of the address when data is being written to the
module. The address or data is xx, represented as two
hex characters. MCB control bytes are displayed with special
3-letter mnemonics:
[SYN] hex 16 synchronization byte
<ACK> hex 06 acknowledge
<NAK> hex 15 not acknowledge
<DC1> hex 11 data control 1
<DC2> hex 12 data control 2
For MAT communications, most of the data bytes are printable
ASCII characters which are displayed simply as the character. The
unprintable ASCII characters are displayed as [xxx],
where xxx is shown in the table below. The "del"
character (127) is displayed as [del].
0 1 2 3 4 5 6 7 8 9
nul soh stx etx eot enq ack bel bs ht
1 lf vt ff cr so si dle dc1 dc2 dc3
2 dc4 nak syn etb can em sub esc fs gs
3 rs us
For RCL communications, each piece of information is displayed as
information sent to the RCL [xxx]
information received from the RCL <xxx>
where xxx is a representation of the data in an
appropriate format. Information going to the RCL is always
displayed in order of: the name of the command being sent followed
by the parameters for that command. Information returned by the
RCL is always displayed in the order of: the error response code,
and if there is no error, the parameter values returned in the
response. The names of the commands, and the order of the
parameters sent and received is the same as that in ISTS's S2-RT
User's Manual, Appendix A. In addition whenever
possible menomonics are substituted for numeric parameters. Error
and parameter menonics correspond closely to those in the appendix
of ISTS's manual. Remote errors are displayed as numeric values
until a successful ERROR DECODE command has been completed
for that error code. Effectively this means that the mnemomic is
not used in the display of remote errors until the second time the
error is encountered after the most recent Field System start. If
the value of a parameter that is normally displayed as menomic
doesn't correspond to the value of a known mnemonic for that
parameter, the hex value will be displayed.
For the TIME READ command the Field System's raw times
immediately before and after the call to rcl time read
are displayed in curly braces {} immediately after the returned
data. The Field System's raw time is the number of centiseconds
since the last boot.
Syntax: enable=track1,track2, ... trackn
Response: enable/track1,track2, ... trackn
Settable parameters:
track1, ... n List of tracks to be enabled/disabled. Mark III track numbers between 1 and 28, and by group. Groups specified by gn, n=1 to 4:
g1 includes tracks 1,3,5,7,11,13.
g2 includes tracks 2,4,6,8,10,12,14.
g3 includes tracks 15,17,19,21,23,25,27.
g4 includes tracks 16,18,20,22,24,26,28.
A null list (i.e. enable=) disables all tracks.
Monitor-only parameters: none
Comments:
MAT module functions available. The use of * as
a parameter is not supported by this command.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses Mark III track and group numbers.
Syntax: enable=list-of-groups
Response: enable/list-of-groups
Settable parameters:
list-of-groups List of track groups to be
enabled/disabled. Groups are specified by gn,
n=0 to 3. A null list
(i.e. enable=) disables all tracks. For mode D,
a single track to be recorded may be indicated by setting list-of-groups
to dn, n = 1
to 28. The group within which Mark III track n
occurs will be enabled.
Monitor-only parameters: none
Comments:
The use of * as a parameter is not supported by
this command.
This command enables groups of tracks in the VLBA recorder.
Tracks may not be individually enabled. The form
command sets up the track assignments with the cross-point switch.
In mode D, an entire group of tracks is enabled. The VLBA form
command must be used to specify which track so that only that
track has data going to it. It is not possible to record in mode D
for a Mark III rack/VLBA drive combination.
g0 includes Mark III tracks 1,3,5,7,11,13.
g1 includes Mark III tracks 2,4,6,8,10,12,14.
g2 includes Mark III tracks 15,17,19,21,23,25,27.
g3 includes Mark III tracks
16,18,20,22,24,26,28.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses VLBA group numbers.
Syntax: enable=stack1,stack2
Response: enable/stack1,stack2
Settable parameters:
stack1,stack2 Stack to be enabled. May be s1
(stack1), s2 (stack2),
or null.
Monitor-only parameters: none
Comments:
MAT module functions available. The use of * as
a parameter is not supported by this command.
Syntax: et
Response: et/acknowledgement
Parameters: none
Comments:
Tape motion is stopped when this command is issued. For Mark III,
the record bit is disabled. For Mark IV, the enabled heads are not
changed. For VLBA, no change is made in the track group enables.
Reproduce mode is not changed; the low tape sensor is not changed.
For Mark IV, see the st command for how to set
up bypass mode.
For S2, the selected transports are stopped.
Examples:
For Mark III, when et is issued the following
MAT commands are sent.
#94=%0xxxxxxx$ turn general enable bit off, same enabled tracks
#94=)07200000$ send stop command, with standard rate generator
For Mark IV, when et is issued the following
MAT commands are sent.
#94=%0xxxxxxx$ turn general enable bit off, same enabled tracks
#94=)08530000$ send stop command, with standard rate generator
Syntax: ff
Response: ff/acknowledgement
Parameters: none
Comments:
The tape is moved forward at high speed. For Mark III, the record
bit is disabled and the low tape sensor is turned on. For VLBA,
all track groups are disabled and the low tape sensor is turned
on.
For S2 drives, the selected transports are moved forward at the
transport's fast forward speed.
For drives other that the S2, the tape is moved at the "schedule"
speed value as specified in the equip.ctl control file. This is
the speed assumed in the SNAP schedule file for positioning the
tape with the fastf procedure.
Use the sff command and sfastf
procedure for possibly faster tape motion.
Syntax: fivept=axis,rep,pts,stp,intp,dev
Response: fivept/axis,rep,pts,stp,intp,dev,cal,beam,flux
Settable parameters:
axis Axis system for scan.
hadc = Hour Angle/Declination (default)
azel = Azimuth/Elevation
xyns = X/Y, +X East
xyew = X/Y, +X South (unimplemented)
rep Number of repetitions: -10 to -1 and 1 to 10 allowed. Default is -2. Negative repetition counts are described in the fivpt manual.
pts Number of points on each axis, if even, it is increased by 1. pts must be between 3 and 31. Default is 7.
stp Step size for distance between points, in multiples of a beamwidth. Default is 0.5.
intp Integration period, 1 to 10 seconds.
dev Mnemonic for the device to be used as the detector.
Standard devices are allowed. Note that for Mark III equipment,
the video converter USB or LSB was set up with the vc
command. The module which has the specified detector must have
been set up. The IF distributor must be set up and, for Mark III,
must be in remote. Default detector is i1 for
Mark III, ia for VLBA.
Display-only parameters:
cal Calibration noise source temperature in degrees K. This is determined from the last caltempx commands in conjunction with the patch (Mark III) or bbc (VLBA) command for the specified device.
beam The full width half maximum beam size degrees. This is determined from the last beamx commands in conjunction with the patch (Mark III) or bbc (VLBA) command.
flux The apparent flux of the source. This is determined
from the last fluxx commands in
conjunction with the patch (Mark III) or bbc
(VLBA) command.
Comments:
The parameters should be setup with a fivept=...
command. A scan is started by issuing a simple fivept
command (i.e. with no parameters), this will determine the current
values of the display only parameters and then schedule an
external program, fivpt, which then uses the Field System to
perform the necessary measurements. fivpt must be included in the
fspgm.ctl control file so that it will automatically be
initialized when the Field System is started. See the fivept
manual in Volume 2.
The scan is performed about the current commanded position. Any
offsets that are in use are included. If the scan is successful
the total offsets for the selected axis type are updated.
It is recommended that nothing else be done, e.g. running a
schedule, while this command is executing. Since this command may
run for an extended period of time, a mechanism has been supplied
for aborting: enter sy=brk fivpt. The program
will then return the antenna to the last good offset for each
axis. If there was no good offset measurement on an axis, then the
original offset is used.
In order for this command to work, the following conditions must
be met: (1) the detector device have been setup by the Field
System, (2) the lo and upconv
commands have been issued, (3) the IF distributor or IF3 module
has been setup by the Field System and is in remote (Mark III
only), (4) the appropriate beamx=...
and caltempx=.... must have been
issued. If a Mark III video converter is used as the detector then
the patch command must have been issued as well.
If estimates of performance based on the source flux are desired,
then the appropriate fluxx=... command
must have been issued as well.
Two procedures must be available: calonfp and calofffp,
which are used by fivpt to turn the noise diode on and off
respectively. The recommended form for these procedures is:
calonfp: calon
!+1s
sy=go fivpt &
calofffp: caloff
!+1s
sy=go fivpt &
calon and caloff are local
procedures that do whatever is necessary to turn the noise source
on and off.
Syntax: flush
Response: none
Parameters: none
Comments:
This command re-initializes the operator procedure stack,
unblocks the operator command stream, and terminates execution of
the current procedure in the operator stream. There is no effect
on the schedule command stream. This is an immediate execution
operator command.
Syntax: flux1=model,flux1,angle1,angle2,flux2,angle3,angle4
flux2=model,flux1,angle1,angle2,flux2,angle3,angle4
flux3=model,flux1,angle1,angle2,flux2,angle3,angle4
fluxa=model,flux1,angle1,angle2,flux2,angle3,angle4
fluxb=model,flux1,angle1,angle2,flux2,angle3,angle4
fluxc=model,flux1,angle1,angle2,flux2,angle3,angle4
fluxd=model,flux1,angle1,angle2,flux2,angle3,angle4
Response: flux1/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
flux2/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
flux3/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
fluxa/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
fluxb/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
fluxc/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
fluxd/model,flux1,angle1,angle2,flux2,angle3,angle4,
corr,aflux
Settable parameters:
model source model, one of gaussian, disk, twopoints
flux1 flux density of the first source component, Janskys
angle1 first angular dimension of the first component
angel2 second angular dimension of the first component
flux2 flux density of the second source component, Janskys
angle3 first angular dimension of the second component
angle4 second angular dimension of the second component
Monitor-only parameters:
corr correction divisor
aflux apparent flux density
Comments:
Source models, for either Mark III or VLBA systems, may be
specified with the flux1/2/3
and fluxa/b/c/d
commands, respectively. The pairs of commands flux1/a,
flux2/b, and flux3/c
are synonymous.
The commands fluxx use the source
model and the beam size specified by the corresponding beamx
to calculate the apparent flux density. The parameter model
determines which model is used and which parameters have meaning.
Parameters which have no meaning for a given model will not be
displayed before the corr parameter.
If model is gaussian, then the source
is assumed to consist of up to two, possibly elliptical, Gaussian
brightness distributions. flux1 gives the flux density
value for the first component. angle1 and angle2
specify the diameters along the two principal axes. angle2
defaults to angel1. flux2 gives the flux
density value for a second concentric optional Gaussian
distribution, default value 0. angle3
and angle4 give the principal axes of the second
component. angle4 defaults to angle3.
If model is twopoints, then the
source is assumed to consist of two equally bright points. flux1
is the total flux density of the two points. angel1 is
their angular separation.
If model is disk, then the source is
assumed to consist of a uniform circular disk brightness
distribution. flux1 is the total flux density. angel1
is the diameter of the disk.
Once the model is specified, the fluxx
command will use the appropriate beam size to calculate the
apparent flux density of the source when the beam is centered
on the brightness distribution. The approximations given in Dave
Shaffer's antenna check-out memo (see the Antenna
Performance manual) are used to compensate for the
finite size of the sources relative to the beam. Note that these
are only approximations and become very poor as the correction
divisor approaches a value of two. Further note that very few
sources are correctly represented by one of these three models.
This command gives a crude approximation to the true apparent flux
density.
Issuing a source=... or a beamx=...
command will automatically change the value of the aflux
parameters to be a negative, invalid, number until a correct fluxx=...
command is issued again. It is recommended that procedures that
include the source=... command and the
appropriate fluxx=... commands be used
to command sources when doing flux density measurements.
See the description of the fivept and onoff
commands for more details on the use of the apparent flux density
values.
Syntax: form=mode,rate,input,synch,aux
Response: form/mode,rate,input,synch,test,sign,run/set,rem/lcl,
pwr,daytime
Settable parameters:
mode Matrix output mode to tape. Choices are a, b, c, d. Default b.
rate Sample rate in Mbits/sec. Choices are 0.125, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0. Default 4.0.
input Source of data. Choices are nor (default), ext, crc.
aux Auxiliary data, up to 12 hex characters. Default is no change. If more than 12 characters are given, only the first 12 are used. If aux has been specified either now or implicitly by a pass, lvdt, or stack command, then the parity command will check its validity.
synch Synch test on (default) or off.
Monitor-only parameters:
test synch test fail or ok
sign synch voltage + or -
run/set switch setting run or set
rem/lcl switch setting, rem or lcl
pwr power interrupt detected, ok or pwr
daytime clock reading in format: ydddhhmmss.ss
Comments:
MAT module functions available.
It may take the formatter up to 4 seconds to re-synch itself if a
change is made to a low sample rate. During this time the
read-back may not be accurate. This module must be reset manually
using the front panel pushbutton in order to clear error
conditions; then turn off alarm remotely. The eight LEDS on the
rear panel of the formatter give some error conditions which are
not available remotely.
The auxiliary data field for the formatter is automatically
filled with the tape head offset by the pass, lvdt,
and stack commands.
Syntax: form=mode,rate,fan,barrel
Response: form/mode,rate,fan,barrel,rev,rack,error
Settable Parameters:
mode The recording mode,choices for the mode are m, a, b1, b2, c1, c2, e1, e2, e3, e4, and dn, where n=1 to 28. No default. Modes a, b, b1, b2, c1, c2, e1, e2, e3, e4 and dn correspond to the traditional Mark III modes. For the bx and cx modes, x corresponds to the sub-pass recorded (odd Mark III tracks for b1 and c1, even Mark III passes for b2 and c2). For the dn modes, n corresponds to the Mark III track number recorded. For the ex modes, x corresponds to the Mark III group number recorded. Mode m uses the sampler track assignments and formatter track enables specified by the trackform and tracks commands.
rate Sample rate in Mbits/sec. Choices are 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, and 32. Default 4. For Nyquist sampling this selection must be twice the bandwidth set-up used in the bbc commands
fan The fan-in or fan-out ratio. Currently, the only choices are 1:4, 1:2, and 1:1, where on a per channel or track basis, the number before the colon is the number of sampled channels and the number after is the number of tracks. Default 1:1.
barrel Barrel-roll mode. Currently the only choice is off,
which is the default.
Monitor-only Parameters:
rev Formatter firmware revision number as an integer.
rack Rack ID, reported as a hex value.
error Error status, okay or the hex value.
Comments:
The Mark IV formatter clock is set with the fmset program. After setting or resetting the formatter time, issue a
sy=run setcl offset & command to reset the
Field System time.
Since the Mark IV recorder does not include group enables, some
of the traditional Mark III mode names used in mode have
numbers appended to them to distinguish which sub-pass, group, or
track is being recorded.
Some combinations of rate and fan cannot be
accommodated by the formatter. No output that would require more
than 16 MHz nominal data rate per track is supported. Specifically
a rate of 32 and a fan of 1:1
is impossible. Some combinations of fan and rate
cannot be accommodated by the recorder. Any combination of rate
and fan that would imply a nominal data rate per track
of 0.125 MHz or less for high density recording (thin tape) is not
supported. Any combination of rate and fan
that would imply a nominal date rate per track of less than 0.125
MHz for low density recording (thick tape) is not supported.
For the time-being, in order to help facilitate debugging of the
formatter in the field, the status of the setable parameters is
logged when the formatter set-up is changed. This information is
logged in the form of the output of the low-level MAT commands
that return this information. Additionally, whenever the formatter
times out or reports an unknown command error (error "7"), the
command that resulted in the time-out or the unknown command error
response is logged. These debugging features will be removed in a
subsequent version.
chekr does not currently support checking of the formatter.
However, the set-up of the formatter can be monitored by entering
a form command. If any of the displayed values
do not agree with the last value commanded, then the formatter is
not in the last commanded state.
Syntax: form=mode,rate,fan,barrel
Response: form/mode,rate,fan,barrel,rev,genstat,mcbstat,hdwstat,sfwstat,intstat
Settable Parameters:
mode The recording mode, reboot (see below) to reboot the CPU, or configure to cause the formatter to perform a hardware configuration. Choices for the mode are prn, v, m, a, b, b1, b2, c, c1, c2, and dn, where n=1 to 28. Default b. Modes prn, m, a, b, b1, b2, c, c1, c2, and dn imply Mark III data replacement format. prn selects pseudo random noise to be sent to all tracks including system tracks. Modes a, b, and c correspond to the traditional Mark III modes. Mode dn is the same as Mark III mode D, where n corresponds to the Mark III track on which the data are written. Mode v implies VLBA non-data replacement format. Modes b1 and c1 are the same as the even VLBA recorder tracks of modes b and c respectively; b2 and c2 are for odd VLBA recorder tracks. Modes m and v use the sampler track assignments and formatter track enables specified by the trackform and tracks commands. The system tracks are disabled except in prn mode.
rate Sample rate in Mbits/sec. Choices are 0.25, 0.5, 1, 2, 4, 8, 16, and 32. Default 4. For Nyquist sampling this selection must be twice the bandwidth set-up used in the bbc commands
fan The fan-in or fan-out ratio. Choices are 1:4, 1:2, 2:1, and 4:1, where on a per channel or track basis, the number before the colon is the number of sampled channels and the number after is the number of tracks. Default 1:1.
barrel Barrel-roll mode. Choices are: off,
8:1, and 16:1, where the number
before the colon is the number of tracks to roll-over. Default off.
Monitor-only Parameters:
rev Formatter firmware revision number, displayed as x.xx.
genstat General status, ok or the hex value of hex address 20.
mcbstat Communications status, ok or the hex value of hex address 21.
hdwstat Hardware status, ok or the hex value of hex address 22.
sfwstat Software status, ok or the hex value of hex address 23.
intstat Internal status, ok or the hex value of hex
address 24.
Comments:
rate and fan combinations that imply more than
8 Mbits/sec of data per tape track or less than 0.25 Mbits/second
of data per tape track are not permitted. The tape clock rate is
set to be 9/8 of the implied data bit rate per track for Mark III
modes, and 9.072/8 of the impled bit-rate per track in VLBA mode.
This command syntax applies to VLBA formatters only. The many
possible error conditions for the formatter are monitored and
reported by chekv (not yet implemented).
MCB functions are available. The formatter CPU can
be reset manually. After manual reset you must issue the command form=addr
to re-initialize the module.
CAUTION: Issuing this command with an equals, =,
causes a formatter reconfiguration which will put the
formatter into a busy state for up to 8 seconds.
The VLBA formatter clock is set with the fmset program. After
setting or resetting the formatter time, issue a sy=run
setcl offset command to reset the Field System time.
In VLBA mode the serial status register is loaded with the
hardware ID (from equip.ctl) in the most significant byte and the
micron position of the head is stored in BCD in the two least
significant bytes; negative values are indicated by the highest
order bit of these two bytes being turned on. In Mark III modes
the hardware ID is placed in the second most significant byte of
the serial status register.
If the requested sampler track assignments and formatter track
enables would imply use of only odd or even recorder tracks only
and the head.ctl control files indicates that only even
or odd tracks are to be used, the sampler
assignments and enables are automatically mapped to the
corresponding even or odd tracks. If both odd and even tracks are
used and/or the head.ctl specifies all heads are
to be used, no mapping takes place. The Mark III modes prn,
a, b, c, dn
assign samplers to and enable all the odd and even tracks
required, so no mapping is required for these modes.
Syntax: form4=command
Response: form/response
Settable parameters:
command any legal command sentence as described in the
Mark IV Formatter Vocabulary manual. The characters \r\n
(carriage-return, line-feed) are appended before sending the
command.
Monitor-only parameters:
response response to command. The >\r\n at
the end of the response is not included in the Field System log.
For accepted commands, which have only >\r\n as the response,
the Field System logs ack.
Comments:
Refer to the Mark IV Formatter Vocabulary manual for a
description of all valid commands and their syntax.
This command is a simple feed-through to the Mark IV formatter.
No checking is done on the command, no action is taken for any
response. This form of the command is temporary while it is
determined what standard parameters are desired.
The command is sent to the MAT bus just as if the
operator had used the mat command. No
modifications are made before the command is sent on the bus.
Use this command to set the formatter clock, with the /TI,
/TR, /TA commands. After setting the formatter time,
issue a sy=run setcl offset command to reset the
Field System time. The fmset program may also be used to set the
formatter time.
Examples:
form4=/ass 0 1:2 3:4 #92/ass 0 1:2 3:4\r\n
Syntax: fsversion
Response: fsversion/version
Monitor-only parameters:
version field system version number.
Comments:
Used to display and log version number of the currently running
field system.
Syntax: halt
Response: none
Comments:
This command halts execution of the schedule until a cont
command is issued by the operator. Once the current schedule
command is finished, no further commands of any kind will be read
from the schedule command stream while the halt
is in effect. Interactive commands from the operator command
stream will still be processed. This is an immediate execution
operator command.
Syntax: hdata
Response: hdata/hd0p,hd1p,hd0t,hd1t,vac,oddpwr,evpwr,ref
Settable parameters: none
Monitor-only parameters:
hd0p Head 0 position.
hd1p Head 1 position
hd0t Head 0 temperature
hd1t Head 1 temperature
vac Vacuum sensor
oddpwr Odd reproduce power
evpwr Even reproduce power
ref Reference voltage
Comments:
MAT module functions available for Mark III. No MCB functions
available.
This command reads the Head Positioner A/D channels, all values
are reported in units of volts. Data from all channels are
reported regardless of whether anything is hooked up to them or
not. In particular, most stations do not use the temperature
channels, the vacuum sensor, and normally only one of the
reproduce power channels is hooked up.
The position voltages (and all others) are reported with the LVDT
off. Use the lvdt command to measure positions
with the LVDT on.
All parameters except oddpwr and evpwr are
null if the drive type specified in the equip.ctl control file is
vlba2.
Syntax: hdcalc
hdcalc=clear
Response: hdcalc/writeF,readF,writeR,readR,writeS,readS
Settable parameters:
none, however hdcalc=clear will delete
previously calculated values
Monitor-only parameters:
writeF Forward absolute offset for the write head
readF Forward absolute offset for the read head, null for VLBA
writeR Reverse relative offset for the write head
readR Reverse relative offset for the read head, null for VLBA
writeS Write head scale
readS Read head scale, null for VLBA
Comments:
This command will calculate new calibration parameters based on
the voltages saved with the savev command. See
the Narrow Track Calibration manual for a
description of the calculations. Only one scale factor is
calculated for each head.
Any parameters which cannot be calculated because savev
has not saved a complete set of voltages will be reported as null,
i.e. empty.
The VLBA recorder has only one head. Its parameters are reported
as the write head parameters and the read head parameters are
null.
Syntax: hecho=on/off
Response: hecho/on/off
Settable parameters:
on/off on to turn echo on, off
to turn echo off.
Monitor-only parameters: none
Comments:
This command prints debug information for commands that use the head positioner (peak and
locate).
Syntax: help=command
?=command
Response: displays information on the screen
Settable Parameters:
command The name of any SNAP command.
Comments:
This command displays available information on the specified SNAP
command. Either the command help or the question
mark ? may be used. Typing help
or ? alone gives help on help.
The help information is essentially the listing of the manual page
for the SNAP command.
This Field System help command opens a new
xterm window and uses the less pager to display the requested help
text one screen-full at a time. At the bottom of the window you
will see a prompt in inverse video that includes the name of the
file being displayed (which you can ignore). If you want to
continue the listing, press the space bar and the next screen-full
will be displayed. To exit from the command, type the letter q
(not echoed on the screen). For help with less, type the letter h
to the prompt. The full options of less are available including
text searches and scrolling back.
In some cases statistics about where in the file the current
screen-full comes from may be displayed in the prompt. In some
cases, less will display only a colon : prompt.
When you see (END) in inverse video in the prompt at the bottom of the screen, you have reached the end of the help information on this topic. Press the letter q to exit. When you press q, the help
xterm window will close automatically. While the text is
displayed in the window you can also use the xterm scroll bar to
move around within the text.
The help information is kept in files in the directory
/usr2/fs/help, one file per command. Versions for different
configurations are distinguished by the two characters in the file
extension for the type of hardware. The first character is for the
type of rack and the second is for the type of recorder. The
characters used are m for Mark III, v for VLBA, 4 for Mark IV, and
for any. The content of the files is the ASCII version
of the pages in this manual. Station-dependent help files are
found in /usr2/st/help.
If no help is available for a command, a message to that effect
will be displayed in the log output window. You will also receive
this message if you request help for a command that is not defined
for your equipment.
Syntax: hpib=mn,data
Response: hpib/data
Settable parameters:
mn 2-character mnemonic of the module to be addressed, as found in the ibad.ctl control file.
data complete message to be sent to module, if any.
Talk-only modules do not accept data.
Monitor-only parameters:
data response of module, if any. Listen-only modules do
not generate any response.
Syntax: ifd=atten1,atten2,input1,input2
Response: ifd/atten1,atten2,input1,input2,rem/lcl,TP1,TP2
Settable parameters:
atten1 IF1 attenuator setting in db, range 0 (default) to 63 db. Enter a numerical value preceeded by + or - to indicate relative change. Other options are max, or old to restore the previous value after a max.
atten2 IF2 attenuator setting in db, range 0 (default) to 63 db. Enter a numerical value preceeded by + or - to indicate relative change. Other options are max, or old to restore the previous value after a max.
input1 IF1 input, nor (default) or alt.
input2 IF2 input, nor (default) or alt.
Monitor-only parameters:
rem/lcl switch setting, remote or local
TP1 IF1 total power reading
TP2 IF2 total power reading
Comments:
MAT module functions available.
The max and old values for
the attenuator parameters allow the attenuators to set to the
maximum value of 63, and then returned to their previous values.
Syntax: if3=atten,mixer,sw1,sw2,sw3,sw4
Response: if3/atten,mixer,sw1,sw2,sw3,sw4,switch,freq,rem/lcl,
LOlock,TPI
Settable parameters:
atten Attenuation in dB, range 0-63, default 0. Enter an integer value preceded by + or - to indicate a relative change. Other options are: max, or old to restore the previous value after max.
mixer Downconverter in or out of the signal path, default out. In response only: 11 or 00.
sw1 Switch 1 state: output to port 1 (default) or port 2.
sw2 Switch 1 state: output to port 1 (default) or port 2.
sw3 Switch 1 state: output to port 1 (default) or port 2.
sw4 Switch 1 state: output to port 1
(default) or port 2.
Monitor-only parameters:
switch present or missing.
freq Synthesizer frequency in MHz.
rem/lcl Switch setting, rem or lcl
LOlock LO lock/unlock status, lock or unlock
TPI Total power integrator reading, decimal, 0-65535.
Comments:
The max and old values for atten
can be used to switch in the maximum attenuation and then restore
the previous (old) attenuation. This is primarily useful for
system temperature measurements. See the sxcts
procedure in the Standard Procedure manual for
an example.
The mixer state commanded by this command and the down converter
frequency specified in the equip.ctl control file are used by the
pcal command to calculate the frequencies of the
phase-cal tones for the video converters that are specified as
connected to IF3 with the patch command. The beam3
command also uses this information to calculate the default beam
size.
If the switch for the mixer is an undefined state, the mixer
response is 11 or 00 depending
on which incorrect state the mixer is in, see the MAT
Protocol manual for details.
The monitor values of the switch settings sw1-sw4 are
null (empty) if the equip.ctl file shows the switch as not
connected. Only switches that have been identified as connected
can be commanded. The switch monitor-only parameter
indicates whether the switch box itself is installed.
The external switch settings sw1-sw4 commanded are not
used to calculate the patching. The effect of the switch settings,
i.e., which video converters are connected to which inputs, must
be specified in the appropriate patch command.
Unless low-pass filters have been installed in some of the output
channels, the IF3 module should only be used to distribute "high"
170-500 MHz IF frequencies to the video converters.
Syntax: ifdab=attenA,attenB,inputA,inputB,avper
Response: ifdab/attenA,attenB,inputA,inputB,avper,TPA,
TPB,serno,err
Settable Parameters:
attenA Attenuator setting for IF channel A. 0 (default) or 20 db. Normally this attenuator should be set to 0 so that the 20 db can be used for radiometry.
attenB Attenuator setting for IF channel B. 0 (default) or 20 db. Normally this attenuator should be set to 0 so that the 20 db can be used for radiometry.
inputA Input source for IF channel A. nor (default) for normal input, ext for front panel IF input.
inputB Input source for IF channel B. nor (default) for normal input, ext for front panel IF input.
avper Averaging period in seconds for the total power
integrator. May be 0, 1, 2,
4, 10, 20, 40,
or 60 seconds. A value of 0
results in 1/80 sec averaging time. Default 1.
The averaging period is synchronous with 1 pps.
Monitor-only Parameters:
TPA Total power in IF channel A in counts. Range 0 to 66535, nominal operating level = 16000.
TPB Total power in IF channel B in counts. Range 0 to 65535, nominal operating level = 16000.
serno Module serial number.
err Module timing error indication, 1pps or no 1pps.
Comments:
This command sets up the IF distributor module that is connected
to channels A and B. Use the ifdcd command to
set up channels C and D. This command is analagous to the Mark III
ifd command.
MCB module functions are available.
The nominal input level to the rack is -20 dbm. If this level is
present then the total power will be at the nominal value and no
extra attenuation will be needed.
Syntax: ifdcd=attenC,attenD,inputC,inputD,avper
Response: ifdcd/attenC,attenD,inputC,inputD,avper,TPC,TPD,serno,err
Settable Parameters:
attenC Attenuator setting for IF channel C. 0 (default) or 20 db. Normally this attenuator should be set to 0 so that the 20 db can be used for radiometry.
attenD Attenuator setting for IF channel D. 0 (default) or 20 db. Normally this attenuator should be set to 0 so that the 20 db can be used for radiometry.
inputC Input source for IF channel C. nor (default) for normal input, ext for front panel IF input.
inputD Input source for IF channel D. nor (default) for normal input, ext for front panel IF input.
avper Averaging period in seconds for the total power
integrator. May be 0, 1, 2,
4, 10, 20, 40,
or 60 seconds. A value of 0
results in 1/80 sec averaging time. Default 1.
The averaging period is synchronous with 1 pps.
Monitor-only Parameters:
TPC Total power in IF channel C in counts. Range 0 to 66535, nominal operating level = 16000.
TPD Total power in IF channel D in counts. Range 0 to 65535, nominal operating level = 16000.
serno Module serial number.
err Module timing error indication, 1pps or no 1pps.
Comments:
This command sets up the IF distributor module that is connected
to channels A and B. Use the ifdab command to
set up channels A and B. This command is analagous to the Mark III
ifd command.
MCB module functions are available.
The nominal input level to the rack is -20 dbm. If this level is
present then the total power will be at the nominal value and no
extra attenuation will be needed.
Syntax: label=vsn,check,type
Response: label/vsn,check,type
Settable parameters:
vsn 8 or 10-character tape VSN, e.g. HS001234
check 4-character check-label corresponding to VSN e.g. 8E45. If no check label appears on the tape, run program labck to generate it.
type thick or thin,
defaults to type implied by VSN. For monitor this value only
appears until the tape is loaded with a rec=load
command. This parameter is not available unless vacuum switching
is enabled in sw.ctl control file.
Comments:
Normally used after newtape command has halted
the schedule. There are two different modes of operation depending
on whether the Volume Serial Number (VSN) has 8 or 10 characters.
When the label command is entered directly by
the operator, 8-character VSN are used. Tape number and check
label must correspond or execution of schedule will not continue.
The effect of this command is the same as that of cont.
Digit zeros (0) and letters Os are both treated as zeros in both
number and check for operator convenience.
The ten-character mode will normally be used only by the rwand
programor a bar code reader. In this mode, the first eight
characters of vsn correspond to the tape number, while
the tenth character is used for a barcode checksum. Any other
parameters are ignored. A fake, but correct, check-label code will
be generated if the barcode checksum is correct.
For VLBA drives and specially equipped Mark IV drives that use
vacuum switching, this command is used specify whether the thick
or thin vacuum level (and for VLBA drives thickness parameters as
well) are commanded. Please see the rec command
for more details.
Syntax: label=vsn,type,code
Response: label/vsn,type,code
Settable parameters:
vsn up to 20 character VSN, e.g., CA-1-0012305
type one or six character tape type, e.g., 1, or 010020, may be omitted if code is csa. If not omitted and code is csa, it must agree with the type specified in the vsn.
code tape label format, an arbitrary string up to 32
characters, default is csa.
Comments:
Normally used after newtape command has halted
the schedule.
If code is csa, vsn is
interpreted as a CSA format, "XX-T-YYYYYZZ-N" label. The
"XX-T-YYYYYZZ" part of label uniquely identifies a set of eight
tapes. The check-sum in checked. If type is specified it
must agree with the "T" type from the vsn, unless six
characters are specified for type. If type is
not specified, the single character "T" from the vsn is
used as the type. The suffix "-N" must be omitted if all eight
tapes in a set are loaded, even if they will not all be recorded
as one group. If fewer than eight tapes are loaded, which tapes
are inserted and the order of their insertion in the transports
should be specified in the suffix. For example if the first four
tapes in a set are inserted in order the suffix "-0123" should be
used. When fewer than eight tapes are inserted they should be
inserted in ascending order and must go into consecutive
transports in ascending order starting with transport 0. Loading
the tapes in this way and using the suffix as described is
necessary in order for the correlator to load the tapes for
playback based only on information available in the log. In
addition, if the tapes are not inserted in consecutive transports
beginning with transport 0, the schedule will probably fail.
For all other values of code, vsn may be an
arbitrary string up to 20 characters long, but type must
be specified in this case.
If the recorder is already recording and a tape type different
than what is use is requested, no change will be made and an error
will be reported.
Syntax: list=start,#lines
Response: display of 10 lines of schedule
Settable parameters:
start place in the schedule to begin listing. May be one of the following:
null to start two lines before the line currently being executed
#line, where line is the starting line number, to start at a particular line number in a schedule
time, in standard SNAP time format, to start at the line which has a time equal to or later than time
#lines number of lines to list, default 10
Monitor-only parameters: none
Comments: Ten lines of the current schedule, with line numbers,
are listed on the terminal. If the current executing line of the
schedule is included in the range listed, it is identified by a
leading right arrow >. Only the active schedule may be listed
with this command. This is a display-only response - no
information is logged.
Syntax: lo=chan1,chan2,chan3
Response: lo/chan1,chan2,chan3
Settable parameters:
chan1 LO frequency for IF channel 1, MHz. Default 0. Normally this is the X-band channel.
chan2 LO frequency for IF channel 2, MHz. Default 0. Normally this is the S-band channel.
chan3 LO frequency for IF channel 3, MHz. Default 0.
Normally this is the high end of the X-band channel.
Monitor-only Parameters: none
Comments:
This command specifies the total LO for each Mark III IF channel.
If your station has an upconverter, use the upconv
command to specify the frequency. If your station has the IF3
module, the frequency of the IF3 LO from the equip.ctl file and
and commanded mixer state are automatically taken into account,
i.e., do not include the effect of IF3 in the LO frequencies.
The LO and upconverter frequencies are used by program pcalr and
by the antenna calibration programs. These values along with the
video converter frequencies are used to calculate the phase
calibrator tone frequencies. For Mark III systems, the patch
command should also be used to specify which converters are on
each IF channel.
Syntax: lo=chanA,chanB,chanC,chanD
Response: lo/chanA,chanB,chanC,chanD
Settable parameters:
chanA LO frequency for IF channel A, MHz. Default 0. Normally this is the X-band channel.
chanB LO frequency for IF channel B, MHz. Default 0. Normally this is the S-band channel.
chanC LO frequency for IF channel C, MHz. Default 0. Normally this is the high end of the X-band channel.
chanD LO frequency for IF channel D, MHz. Default 0.
Monitor-only Parameters: none
Comments:
This command specifies the total LO for each VLBA channel. If
your station has an upconverter, use the upconv
command to specify the frequency.
The LO and upconverter frequencies are used by the antenna
calibration programs.
Syntax: locate=range,nsamples,step,stack
locate
Response: locate/range,nsamples,step,stack,peakv,mper,vltlc
Settable parameters:
range range to search over in microns. Default is 200.
nsamples Number of power samples for each measurement position. Default is 1.
step Micron step size between measurement positions. Default is 40.
stack Head stack to move: write or read.
1 and 2 may also be used to
mean the write and read head stacks, respectively. Only the first
character is checked. Only write is valid for
VLBA recorders, this is the default. For Mark IV recorders, use write
or 1 for head stack 1, read or
2 for head stack 2. Default is read
for Mark III and Mark IV.
Monitor-only parameters:
peakv Peak measured voltage from power detector
mper Minimum sample voltage as a percentage of peakv
vltlc Location of the peak in positioner voltage
Comments:
This command performs a coarse grid search for the largest
detected power over the search range. The search is performed over
a range of range microns about the initial head
position. The number of positions sampled is ((2*range)/step)+1.
The actual positions at which measurements are made are not
exactly step microns part. The head stack will be
positioned within 5 microns of the nominal positions. This
approximation is used to reduce the time moving the head stacks by
not over-refining the positions of what is a coarse search anyway.
In the worst (too coarse) case two positions might be step+10
microns apart.
After sampling over the complete range, locate
returns the head stack to the position that gave the highest power
level, makes a new measurement and reports these values for the peakv,
mper, and vltlc parameters.
This command requires that the reproduce power detector be
hooked-up with a reasonable amount of attenuation and that the
head.ctl control file correctly identify which detector (odd or
even) is in use.
This command must be issued once with parameters to set it up.
Issuing the command subsequently without parameters will start a
search. The tape must moving and there must be recorded data to
reproduce for this command to do something useful.
See the Narrow Track Calibration manual.
Syntax: log=name
Response: log/name
Settable parameters:
name name of log file to be opened. If no directory path
is specified, /log is assumed. If no extension is specified, .log
is assumed.
Monitor-only parameters: none
Comments:
When the Field System is initialized, log file station.log was
opened or created in directory /usr2/log. If the log file
requested by this command cannot be opened or created, the Field
System returns to using the log file previously in use. If no log
file can be successfully opened, execution of the schedule
continues, but an error message is displayed on the screen every
time an attempt is made to write into the log.
This command is not implemented.
Syntax: logout=file,mode,bits,parity,stop
logout=*,file,mode,bits,parity,stop
Response: logout/file,file,
Settable parameters:
dev File name for display output. This may either be a normal file, e.g., /tmp/logout, a pseudo-terminal device file that is in use as an xterm, e.g., /dev/pts011, or a serial port device file, e.g., /dev/cui1h. No default.
mode Open mode for file, one of append, write, or a valid BAUD rate: 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, or 38400. The default is write. If a BAUD rate is specified it implies that the file being opened is serial device. The remaining parameters may be used to define the line protocol.
bits The number of bits per character transmitted, one of 5, 6, 7, or 8. The default is 8.
parity How parity generation is handled: none, odd, or even. The default is none.
stop The number of stop bits, one of 1
or 2. The default is 1.
Comments:
Log entries are always written into the log file and sent to the
display device for the ddout program. This command can be used to
send the displayed output of the ddout program, both log entries
and information messages (including bus communications echoing) to
other terminals, devices, and files. This command is useful for
recording the displayed output in a file for later examination or
to direct the output to an auxiliary display.
Up to five different output files (or devices) can be in use at
any time. However, only one new device can be specified per logout=
command. If the logout=*, form is used,
the specified file receives the display output in addition to
those already doing so. If the form without the asterisk "*"
as the first parameter is used, any files currently in use will be
closed and the specified file will be opened. The command logout=
with no parameters will close any files current receiving output.
The line protocol parameters bits, parity,
and stop are useful only if the mode was
specified as a valid BAUD rate. The default mode, write,
will cause the specified file to be overwritten if it already
exists.
If a file is not specified as an absolute pathname, i.e., without
a leading slash "/", the file will be opened in the current
directory that the Field System was started from, usually /usr2/oper.
Because of the mapping of all command input to lower case, it is
not possible to open a file that contains any upper case letters.
This files can still be opened if they are linked to a another
file name that does not contain upper case letters. For example,
the file /dev/ttyF01 could be linked to /dev/ttyf01 using the UNIX
command: ln /dev/ttyF01 /dev/ttyf01. Then
/dev/ttyf01 can be used as the file name. Also because of the
special meaning of asterisk "*" as the first
parameter it is not possible to open a file with a name of
asterisk unless the logout=*, command
form is used.
Files are opened with the permissions of the user that started
the Field System, usually oper.
Syntax: lvdt=cmdVw,cmdVr
Response: lvdt/cmdVw,cmdVr,actVw,actVr,deltaVw,deltaVr
Settable parameters:
cmdVw Command position voltage for the write head stack, default is don't move. For Mark IV this parameter refers to head stack 1.
cmdVr Command position voltage for read head stack,
default is don't move. This parameter is not valid for VLBA
recorders. For Mark IV this parameter refers to head stack 2.
Monitor-only parameters:
actVw Actual position voltage for write head stack (Mark IV stack 1)
actVr Actual position voltage for read head stack (Mark IV stack 2), null for VLBA
deltaVw Voltage difference between actual and commanded write head stack position (Mark IV stack 1).
deltaVr Voltage difference between actual and commanded
read head stack position (Mark IV stack 2), null for VLBA
Comments:
This command is used to position the head stacks in voltage
units. An individual stack may be moved by not specifying a
command voltage for the other stack. The commanded positions are
uncalibrated.
VLBA recorders have only one head stack. Its positioning is
specified by using the first (write) stack parameter. Monitor
parameters for the read head stack are reported as null.
For Mark IV recorders, the write head stack parameters correspond
to head stack 1, the read head stack parameters to head stack 2.
The deltaVx parameters are reported with the sign of
actual minus commanded.
The command positions reported by the lvdt, pass,
and stack commands are consistent. See the
description of the pass command for more
information.
If the write head stack position is commanded, the auxiliary data
field is set to reflect the commanded position, see the pass
command for more information. (Not yet implemented for VLBA.)
For VLBA2 drives, the voltage units are actually in kÅ (0.1
microns) of head position. This implies that the scale is expanded
by a factor of about 1500 over the LVDT voltage scale of other
drives.
Syntax: mat=data,data,...
Response: mat/data,data,...
Settable parameters:
data complete message to be sent to MAT system,
including actual hex address and all other protocol. No checking
is done. Each message between commas is sent separately. All
special non-printing characters, such as escape, should be typed
directly on the keyboard or they will be sent as typed. EXCEPTION:
The character enq will be substituted for any TAB encountered in
the message.
Monitor-only parameters:
data response of MAT system, if any, to each message.
Syntax: matload=unit addr,mem addr,data
Response: matload/acknowledgement
Settable parameters:
unit addr the hex address of the MAT to receive the code.
mem addr the hex location for the start of the load, 4 characters.
data the hex data bytes to be transmitted, must be an
even number of them.
Comments:
The message to the unit that is sent:
#unit addr:nnmem addr00datacc
where nn=number of data bytes, cc=check sum. Remember that 2-byte
data values are sent least significant, most significant.
Syntax: mcb=module,reladdr,value
Response: mcb/value
Settable Parameters:
module Module mnemonic indicating which module is to be addressed. Only standard module mnemonics allowed. Use null to indicate that the following address is an absolute address.
reladdr Relative MCB address (hex), i.e. the offset from the module's base address. This is the address to be read if a value is not given. This is the address to write to if a value is given. If module is null, then this is an absolute address.
value Value (hex) to be written into reladdr.
Omit this parameter if you want to read reladdr.
Monitor-only Parameters:
value Value (hex) that was read from reladdr,
if a value was not specified in the command. If a value was
specified in the command, then the response is the status of the
write: OK, BUSY, ERR.
Comments:
This command is analgous to the Mark III mat
command. This command is used to read values from or write values
to a specific MCB address.
If the command is issued as mcb=module,reladdr
then the response is the hex value at reladdr.
If the command is issued as mcb=module,reladdr,value
then the value is downloaded into reladdr and the
response is the status.
Syntax: newtape
Response: newtape/"To continue, use LABEL command"
Comments:
This command in effect is the same as the halt
command. Execution will continue after the label
command has been successfully completed. The cont
command will also work.
Syntax: onoff=rep,intp,dev1,dev2,cutoff,stp
Response: onoff/rep,intp,dev1,dev2,cutoff,stp,cal1,cal2,
beam1,beam2,flux1,flux2
Settable parameters:
rep Number of repetitions, 1 to 99. Default is 2.
intp Integration period, 1 to 10 seconds. Default is 1.
dev1 Device to be used as detector 1. Standard detector mnemonics are allowed. Default is i1 for Mark III, ia for VLBA.
dev2 Device to be used as detector 2. Standard detector mnemonics are allowed. Default is i1 for Mark III, ib for VLBA.
cutoff elevation above which to step in elevation rather than azimuth, in degrees, default 60.
stp Distance off source for off source and calibration
points, in multiples of a beamwidth. Default is 5.0.
Monitor-only parameters:
cal1 Calibration noise source temperature in degrees K for detector 1. This is determined from the last caltempx command in conjunction with the patch (Mark III) or bbc command.
cal2 Calibration noise source temperature in degrees K for detector 2. This is determined from the last caltempx command in conjunction with the patch (Mark III) or bbd command.
beam1 The full width half maximum beam size (degrees) for device 1. It is determined from the beamx command and the patch (Mark III) or bbc (VLBA) command.
beam2 The full width half maximum beam size (degrees) for device 2. It is determined from the beamx command and the patch (Mark III) or bbc (VLBA) command.
flux1 The apparent source flux for device 1, based on the fluxx command and the patch (Mark III) or bbc (VLBA) command.
flux2 The apparent source flux for device 2, based on
the fluxx command and the
patch (Mark III) or bbc (VLBA)
command.
Comments:
The parameters should be setup by issuing a onoff=...
command. A measurement is started by issuing a simple onoff.
This will recover the current values for the display only
parameters and schedule an external program onoff. onoff should be
placed in fspgm.ctl, so that it is initialized automatically when
the Field System is started. See the onoff
manual in Volume 2.
The current command antenna position including offsets is assumed
to be "onsource."
It is recommended that nothing else be done, e.g. running a
schedule, while this command is executing. Since this command may
run for an extended period of time, a mechanism has been supplied
for aborting: enter sy=brk onoff in response to
a system prompt. After aborting, the offsets will be returned to
their original values.
In order for this command to work, the following conditions must
be met: (1) the detector devices have been set up by the Field
System, (2) the lo and upconv
commands have been issued, (3) the IF distributor has been set up
by the Field System and it must be in remote (Mark III only), and
(4) the appropriate beamx command has
been issued. Additionally, if a video converter is used as a
detector, the patch command must have been
issued. If system performance is to be estimated based on the
source's apparent flux, then the appropriate fluxx
command must have been issued.
If a negative value is specified for the noise diode temperature
(caltempx=....) for either detector,
then the absolute value of the specified temperature is assumed to
be the system temperature for that detector and the signal level
with the noise diode on is not used. The noise temperature for
either one or both channels can be specified as negative. If both
are negative, the noise diode won't be turned on. This allows the
SEFD and Shaffer number to be measured even if there is no noise
diode; the source/cal ratio in this case will be wrong and will be
negative.
If a positive diode temperature has been specified for either
detector, two procedures must be available: calonnf
and caloffnf, which are used to turn the noise
diode on and off respectively. The recommended form for these
procedures is:
calonnf: calon
!+1s
sy=go onoff &
caloffnf: caloff
!+1s
sy=go onoff &
calon and caloff are local
procedures that do whatever is necessary to turn the noise source
on and off.
Syntax: onsource
Response: onsource/status
Settable Parameters: none
Monitor-only Parameters:
status tracking or slewing, depending on the errors in
pointing.
Syntax: op=name
Response: none
Settable Parameters:
name Operator name or initials, maximum of 12
characters. Embedded blanks are allowed.
Syntax: op stream=command
Response: none
Settable Parameters:
command The command to be placed in operator command
stream.
Comments:
This command can be used from the schedule to enter commands into
the operator stream. This is useful because time-scheduled command
entered from the schedule stream will be blocked when the schedule
is executing a timed wait.
This command might be used to periodically record TPI values
during an observation. For example, the following procedures might
be used to sample TPI values every 10 seconds during an
observation:
MIDOB: op stream=start
START: collect@!,10s
COLLECT: tpi=odd,even,if1,if2
POSTOB: collect@
A great deal of care needs to be exercised when using this
command. In particular, command should not cause any
long timed waits to occur since this will block the operator
stream (in a pinch, the operator stream can be freed from a long
wait by using the flush command). Also no
command that might cause interference with the execution of the
schedule should be used. In particular this would mean avoiding
use of tape motion commands.
Note that any use of @ in command is
interpreted to apply to the op stream=
command itself and is removed from command before what
is left is placed in the operator stream. This is the reason that
the START procedure was necessary in the example above.
This command is considered experimental. It creates a new type of
interaction between the schedule and operator streams. It may be
necessary to modify or remove this feature if some unanticipated
consequence proves to be a problem.
Syntax: parity=pemax,syncmax,channel,aux,tracks
parity
Response: parity/parity-errors
parity/sync-errors
Settable Parameters:
pemax Maximum allowable parity errors per channel per megabyte of data. Default is 600. If errors exceed threshold, an error message is issued.
syncmax Default is 12. Otherwise handled the same as parity error threshold.
channel Decoder channel. Can be a, b, or ab (default).
aux Aux data check, on (default) or off. Not supported for VLBA.
tracks List of recorder tracks on which to measure
errors. Default is the currently enabled tracks. For Mark III
drives, tracks and must be between 1 and 28,
and/or may be specified by groups (g1, g2,
g3, g4) as in the enable
command. For VLBA drives, tracks must be between 0
and 35, or specified by groups (g0,
g1, g2, g3)
as in the enable command, or specified as
non-system tracks in the VLBA groups (v0, v1,
v2, v3),or specified as the
Mark III tracks in the VLBA groups (m0, m1,
m2, m3). For Mark IV, values
are Mark IV/VLBA tracks and must be between 0
and 35, and/or may be specified by all
which means tracks 2 through 33.
Monitor-only parameters:
parity-errors For each track in the list, the corresponding parity errors (smallest of 4 samples).
sync-errors For each track in the list, the
corresponding sync errors (smallest observed value over the same 4
sample intervals as the parity error check).
Comments:
Issuing this command with an equal sign without or without a list
of parameters sets up the command. Issuing the command with no
equal sign then measures errors.
This command assumes the read head stack is positioned
appropriately for the tracks that will be read. The heads that are
used to reproduce data are automatically mapped from even to odd
or vice-versa depending on the reproduce electronics specified in
the head.ctl control file. For VLBA and VLBA2 drives the write
head parameter controls which heads are used. If a mixture odd
asnd even heads are requested no mapping is done.
If the auxiliary data field was set using the form
or head positioning commands, then it is checked for accuracy,
unless the aux parameter is off. An
error message is issued if the auxiliary data on the tape does not
agree with the value last sent to the formatter.
If so many tracks are decoded that the response extends beyond
about 100 characters, then another response line is generated.
The decoder channels used to read the data can be specified,
either a, b, or both a
and b reproduce channels can be used. If pcalr
is running, it should be suspended before starting this command so
that there's no competition for the b channel.
Five error readings are made from the decoder or DQA, spaced 0.25
seconds apart. Actual parity errors are the difference between
successive readings. The minimum of the 4 parity error values is
reported in the response. (In versions before FS8.0, the Mark III
command used a time difference of 0.34 seconds.) Each round trip
communication with the decoder takes approximately 0.12 sec, plus
the 0.25 seconds wait time yields 48 seconds to check 28 tracks,
24 seconds to check 14 tracks.
Parity errors are reported as the number of errors per 1 million
bits of data. The actual number of parity errors is scaled to
account for the tape speed during playback.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses VLBA, Mark IV, or Mark III track and VLBA or Mark III
group numbers depending on the type of drive in use.
For a Mark IV drive, if vacuum switching is enabled in the sw.ctl
control file, the vacuum level must established before the parity
command is issued. The vacuum level can be established either by
entering the tape label with the label command
and then loading the tape with the rec=load
command or simply turning off the vacuum with rec=novac.
Please do not try to turn change the vacuum when the tape is
moving.
Syntax: pass=cmdPw,cmdPr,woffset
Response: pass/cmdPw,cmdPr,woffset,cmdMw,cmdMr,actMw,actMr,
deltaMw,deltaMr
Settable parameters:
cmdPw Command pass number for write head stack (Mark IV stack 1), range 1-100 for Mark III and VLBA, 1-112 for Mark IV. Default is to not move the write head stack. For Mark IV recorders, if the parameter is stack2, then stack 1 is moved to the most recently commanded stack 2 position.
cmdPr Command pass number for read head stack (Mark IV stack 2), same range as for write head stack. This parameter may not be specified for VLBA recorders. If the parameter is same, the read pass will be same as the write pass. For Mark IV, if the parameter is mk4, then stack 2 is positioned to 100 plus the pass number for stack 1. Default is to not move the read head stack.
woffset Type of offset for the write head. auto
(default) or none. Only the first character is
checked. For auto, the head stack position is
automatically adjusted according to the write head type parameter
in the head.ctl control file. For none, no
adjustments are made. Use none for Mark IV
recording and for all mode A recording. The read head is always
adjusted.
Monitor-only parameters:
cmdMw Microns corresponding to command write head pass number.
cmdMr Microns corresponding to command read head pass number, null for VLBA.
actMw Microns corresponding to actual write head pass number.
actMr Microns corresponding to actual read head pass number, null for VLBA.
deltaMw Micron error between actual and commanded write head position.
deltaMr Micron error between actual and commanded read
head position, null for VLBA.
Comments:
This command moves the read and/or write head stacks to the
position for the commanded passes. The correspondence of pass
numbers to a priori micron positions is established by the tapeform
command. The requested pass must have been set-up by the tapeform
command to be used. Odd pass numbers are used for forward passes,
even for reverse.
Only the write head stack parameters in this command are used for
VLBA recorders. The read head stack parameters are reported as
nulls. For Mark IV, the write head stack parameters refer to head
stack 1, the read head stack parameters refer to the head stack 2.
The head stack position in microns is determined by
position = tapeform offset + absolute offset (forward pass)
position = tapeform offset + absolute offset + for/rev offset
(reverse pass)
where tapeform offset is the a priori offset as
specified with the tapeform command, and the absolute
offset and forward/reverse offset are specified
in the head.ctl control file.
If woffset is auto, and the commanded
pass is a reverse pass, and the write head stack is defined as odd
in the head.ctl control file, then an offset of 698.5 microns is
added to the write head stack position.
If woffset is auto, and the commanded
pass is a forward pass, and the write head stack is defined as even
in the head.ctl control file, then an offset of 698.5 microns is
subtracted from the write head stack position.
If woffset is none, then no offset is
applied to the a priori offset for the write head. The read head
is always adjusted.
An individual head stack can be moved by not specifying a command
pass number for the other head stack. The read (stack 2) command
pass can be same, which causes it to be the same
as the write head stack pass number. This feature is useful for
setting both head stacks to the same pass number in set-up
procedures. The read (stack 2) command pass can be mk4,
which causes head stack 2 to be positioned to the position for the
pass number specified for head stack 1 plus 100. This feature is
useful for positioning both Mark IV head stacks using a single
pass number in set-up procedures. Also for Mark IV, the write
(stack 1) command pass can be stack2, which
causes head stack 1 to be positioned to the most recently
commanded position of stack 2. This feature is useful for
positioning stack 1 (the only stack that can play back) to read
tracks that were just recorded with stack 2.
The deltaM parameters are reported with the sign of
actual minus commanded.
The commanded positions of the lvdt, pass,
and stack commands are reported consistently.
For example, if you command the head stack positions with the stack
or pass command, you can determine the
corresponding command voltage with lvdt. And
vice-versa, the micron position corresponding to a voltage
position commanded with lvdt can be determined
with stack or pass.
The commanded pass numbers reported by pass are
given special values if either lvdt or stack
last commanded the positions. If lvdt or stack
is used with uncalibrated positions, the commanded pass number
will be reported as 0. If the stack command with
forward calibrated positions was used, -1 will be reported for the
pass number, for reverse calibrations -2 will be reported.
For Mark III, when the write head is moved by either pass,
stack, or lvdt, the auxiliary
data field used by the formatter is set to reflect the commanded
position. The twelve characters of the auxiliary data field are
set as:
xxwxwxyzyzff
xx ff for forward calibration (odd passes)
fe for reverse calibration (even passes)
fd for uncalibrated positions.
wxyz 0000-3999 for positive micron positions
4000-7999 for negative micron positions
ff hex characters ff
The positions occupied by wxyz are the four digits of
the commanded micron write head position. In the auxiliary data
field the digits are repeated two at a time. The negative
positions are represented as the 4000+ absolute value of the
position. The xx field is used to identify which type of
calibration was used to set the position. The last two digits of
the auxiliary data are fixed with the value ff.
For VLBA, the auxiliary data field is not supported.
For Mark IV, there are eight characters (32 bits) available for
auxiliary data. They are set as:
abcdwxyz
abcd head stack 0 position in microns
wxyz head stack 1 position in microns
Characters a and w have the following bit
structure:
bit 0 thousands digit for the micron position, usually 0
bit 1 0 for forward calibration (odd passes), 1 for uncalibrated
bit 2 0 for reverse calibration (even passes), 1 for uncalibrated
bit 3 sign of the position, 0 for positive, 1 for
negative
Syntax: patch=lon,vc#horl,...
Response: none
Settable Parameters:
lon One of lo1, lo2, or lo3. No default.
vc#horl Video converter number with the character h
or l appended, e.g. 1h or 3l.
h indicates the high band of the channel, and l
the low. No default.
Comments:
This command stores the patching information for access by
program pcalr and the antenna calibration programs. This command
identifies which video converters are patched to channel 1, which
to channel 2. This command is not needed for VLBA systems because
the bbc command specifies the connections.
The lo command should also be used to specify
the LO frequencies, and the upconv command
should be used if you have an upconverter.
Syntax: pcal=#cycles,pause,repro,#blocks,debug,track,
...
Response: none
Settable parameters:
#cycles Number of times to cycle through tracks. 0 = run continuously (default).
pause Time to pause between cycles, seconds. Default is 60 seconds.
repro Type of reproduce mode:
fs = use current mode set up by Field System
by = use bypass mode
rw = use read after write mode
ab = use split mode (implies bypass mode too)
If an experiment is in progress (i.e. if a schedule file is active) then fs is the recommended mode. Attempts to force read-after-write or bypass may result in compromising execution of the schedule.
#blocks Number of blocks to average, default 25. The default gives 5 degrees rms phase noise or an SNR of 10.
debug 0 for no debug printout (default). A value of +1 prints the data buffer status each time it responds. A value of +2 will print the actual data and more detailed status information. The values -1 and -2 will simply test communications with the data buffer and then quit.
tracks Tape recorder track(s) to use. 0
= use all tracks for current mode (default). A list of track
numbers may be given. A list of video converters may be specified
by preceding each number with v. The words all,
even, odd referring to tracks
and vall, veven, vodd
referring to VCs may be used. Split mode will be set up for the
outer channels in the frequency sequence, if bypass mode is set
up.
Comments:
Invoking this command with no parameters activates pcalr. To stop
pcalr, use the command sy=brk pcal. Before
starting pcalr, specify LO frequencies with the lo
and upconv commands, set up IF3 with the if3
command, and specify patching with the patch
command.
Syntax: peak=nsamp,iter,stack,vmin
peak
Response: peak/nsamp,iter,stack,vmin,peakv,mper,t/f,vltlc
Settable parameters:
nsamp Number of samples to take at each position. Default is 3.
iter Number of times to iterate peak finding. Default is 1.
stack Head stack to move for peaking: write (default) or read. Only the first character is checked. Only write is valid for VLBA recorders. For Mark IV recorders, use write for the head stack 1, read for head stack 2.
vmin The minimum peak voltage that is required before
the peak is considered "real". Default is 0.2
volts.
Monitor-only parameters:
peakv The voltage measured at the calculated peak position.
mper The minimum voltage measured at the peak as a percentage of peakv.
t/f t (true) if the peak is strong enough to be considered a real peak and the middle of the last three measured positions is within 5.4 microns of the calculated peak, f (false) otherwise.
vltlc voltage position of the calculated peak response
Comments:
This command attempts to find the head stack position that gives
the peak response from a track. This should work if the head stack
is already positioned so that there is some reproduce power coming
from the track. The algorithm is:
(1) Measure the reproduce power at the current position.
(2) Move 8 microns toward the plate (in) and measure the power again.
(3) If the power at position two is greater than that at position one, move another 8 microns in and measure the power again. If the power at position two is lower than the power at position one, go out from position one 8 microns and measure the power again.
(4) Continue moving the stack 8 microns at a time in the direction that increases the power until there are three measurement with the highest power in the middle position. No more than 5 additional measurements are made.
(5) Fit the final three positions to a triangular model for the response.
(6) Move the stack to the calculated peak position. Measure the
final power level.
When positioning the 8 micron step size is only approximate. The
positioning is done with 2.7 micron tolerance to avoid spending
too much time refining the position.
This command requires that the reproduce power detector be
hooked-up with a reasonable amount of attenuation and that the
head.ctl configuration file correctly identify which detector (odd
or even) is in use.
A reproduce track must be selected with the repro
command in order to peak the power. Depending on the cabling,
either channel A or B should be used. Setting both channels to the
same track is sure to work unless the detector isn't connected.
In order to identify possibly false peaks, peak
requires two conditions be met before a peak is accepted: (1) the
voltage read-out of the power level must exceed the set minimum
and (2) the calculated peak position must be within 5.4 microns of
the middle position of the last three sample values. The first
attempt to peak on a track may fail because of the second
criteria. A second attempt should succeed if that was the problem.
It may be necessary to raise or lower the minimum voltage if the
noise level is higher than normal or the peak response is lower
than normal.
This command must be issued once with parameters to set it up.
Issuing the command subsequently without parameters will start a
peaking operation. The tape must moving and there must be recorded
data to reproduce for this command to do something useful.
This command differs from the locate command in
two ways. The first is that locate is intended
to do a coarse search only. peak searches with
smaller and more precise steps. Secondly, locate
will return the head to the position of the largest measured
voltage. peak will make measurements until it
has straddled the peak and then will move to an interpolated peak
position.
See the Narrow Track Calibration manual.
Syntax: perr=track,chan,#samples,period,mode
Response: perr/track,chan,#samples,period,mode,error,synerr
Settable parameters:
track Track to be decoded. No default.
chan Decoder channel A (default) or B.
#samples Number of samples to average, maximum 10, default 2.
period Time between samples in seconds, maximum 2, default 0.5.
mode rec or play,
default rec.
Monitor-only parameters:
error Average number of parity errors.
synerr Total number of sync errors.
Comments:
This command sets up the appropriate track for reproduce, and
then reads the decoder one more than the specified number of times
with the specified amount of time between samples. Differences
between successive readings are averaged to calculate error. The
difference between the first and last synch error readings is
synerr. In rec mode, track must be enabled, the
tape must be moving forward, record must be enabled, and reproduce
must be in read-after-write mode. In play mode,
only read-after-write and moving tape are checked. In either mode,
if the measurement of parity errors is precluded by the tape
status, then nothing is done and no error message appears. (See
also parity command.)
Syntax: proc=name
Response: proc/name
Settable parameters:
name name of procedure file to open. If no directory
path is specified, /usr2/proc is assumed. If no extension is
specified, .prc is assumed. This procedure library is opened as
the schedule library, and all procedure names are read.
Monitor-only parameters: none
Comments:
When a new procedure library is opened, any time-scheduled
procedures from the previous procedure library are canceled. See
section 8.0 of the SNAP Language manual for
details. Refer to the pfmed manual for
information on editing procedure libraries.
Syntax: radecoff=ra,dec
Response: radecoff/ra,dec
Settable parameters:
ra Right ascension offset, in numeric angle/hours format. The response is in numeric angle/hours format.
dec Declination offset, in numeric angle/degrees format.
The response is in numeric angle/degrees format.
Monitor-only parameters: none
Comments:
The antenna will move to the offset position when this command is
issued. To return to the on-source position, issue this command
with zero for the offset.
Syntax: rcl=device,command,parameters, ...
Response: rcl/response
Settable Parameters:
device The two character module mnemonic for the device to communicate with as defined in the rclad.ctl control file, e.g. rc for the S2
command name of RCL command function
parameters command delimited additional parameters required for this RCL command function
Monitor-only Parameters:
response Result of communication, may displayed on
multiple lines for ease of reading.
Comments:
This command implements access to all the low-level functions of
the RCL interface. Check ISTS's S2-RT User's Manual,
Appendix A for detailed information about the command
names, their parameters, and the responses. The following table
lists very briefly the commands and the parameters, if any, that
the rcl command expects for each. For parameters
that have values that consist of choice among fixed items, it is
possible to enter a numeric value as well, in which case it is
passed directly to RCL interface without checking.
Command Parameters
align absolute,year,day,hour,min,sec,nanosec
relative, + or -,hour,min,sec,nanosec
re-align or self-align
barrel roll read
barrel roll set on or off
bercd fmber or uiber or uidcb, chan, measurement time
consolecmd command string
delay read
delay set absolute or relative,nanoseconds
delaym read
diag value
eject
errmess samples
esterr read transport or channel
ff
group read
group set group number
ident
mk3 form read
mk3 form set enable or disable
mode read
mode set mode string
pause
pdv read transport or channel
ping time-out
play
position read overall or individual
position set absolute or relative or preset,1,position
absolute or relative or preset,8,8 comma seperated positions
re-establish
postime read transport
record
rewind
speed read
speed read pb
speed set lp or slp
state read
station info read
stop
tapeid read
tapeid read pb
tapeid set tapeid string
tapeinfo read pb
tapetype read
tapetype set tape type character or string
time read
time read pb
time set year,day,hours,minutes,seconds
transport times
unpause
user dv read
user dv read pb
user dv set true or false, ignore or use
user info read field number,field or label
user info read pb field number,field or label
user info set field number,field or label,string
spcll mode set xtal or manual or refclk or 1hz or errmes
status
status decode status code,true or false
status detail status code,true or false, true or false
version
Syntax: rec=list
Response: rec/position,variance,date/time,valid,version
Settable Parameters:
list One of eject (or unload),a
position to move all selected transports to, or a list of eight
comma separated positions to move the individual transports too.
Positions are in units of seconds. In a list of eight positions, uns
must be used for transports that are not currently selected.
Monitor-only Parameters:
position overall absolute position of select transports, unk if unknown.
variance linear variance of position of select transports, unk if unknown.
date/time S2 date and time in format yyy/ddd.hh:mm:ss
valid valid if S2 time is valid, not-valid if S2 time is not valid
version ROS softwarre version information string
Comments:
This command is used to move the selected transports to another
position.
Syntax: rec=action
Response: none
Settable Parameters:
action A key word specifying what you want the recorder to do. Choices are:
load Load a tape into the vacuum columns. This is similar to pressing the stop button, but also guarantees that the low tape sensor has not been tripped. On Mark IV drives with vacuum switching it also commands the vacuum level based on the most recent label command before attempting to load the tape.
novac On Mark IV drives with vacuum switching
this removes the vacuum.
Comments:
For Mark III and Mark IV drives without vacuum switching, this
command can only be used to load the tape.
For Mark IV drives with vacuum switching, the rec=load
command sets the vacuum level based on the tape thickness selected
by the most recent label command. For these
drives there is an added restriction that the tape thickness be
must specified with a new label command before
every rec=load command. This is intended to
reduce the likelihood that the incorrect vacuum level will be set.
Please try to avoid removing the vacuum with rec=novac
if the tape is moving. Doing so may well damage the tape.
Syntax: rec=action
Response: rec/feet,supply,takeup,length,revno
Settable Parameters:
action A key word specifying what you want the recorder to do. Choices are:
reboot Reboot the microprocessor in the recorder. See comments below.
load Load a tape into the vacuum columns. This acts like the stop button on the Mark III recorders. Brakes are released. The parameters in equip.ctl are downloaded to the recorder.
unload Move the tape at high speed to the low tape point near BOT. Wind the tape off the reel at 90 ips.
bot Move tape at high speed to BOT (beginning of tape) at stop.
eot Move tape at high speed to EOT (end of tape) at stop.
release Release the reel brakes. Drop the vacuum and then issue this command before trying to thread a tape.
feet Move the tape to the specified footage.
feet Set the tape footage counter. The supply and takeup reel packs in feet are read back and the footage counter is set to the takeup reel pack. These values are accurate to about 50 feet.
zero Reset footage counter to zero.
Monitor-only Parameters:
feet The current footage counter reading.
supply Footage left on the supply reel.
takeup Footage left on the takeup reel.
length Total length of the tape, supply+takeup.
revno Software revision number.
Comments:
The feet option of this command is analagous to the
Mark III tapepos command. The zero
option is analagous to the Mark III tape=low,reset
command. The other options are unique to the VLBA recorder.
MCB functions are available.
The recorder can be re-booted manually by pressing the red
button. After manual reset you must issue the command rec=addr
to re-initialize the module.
Before the actions unload, bot,
eot, or feet are taken, the ready state
of the recorder is checked. If the recorder is not ready, an error
is logged and the action is not taken.
If the drive type specified in the equip.ctl control file is vlba2,
the supply, takeup, and length
parameters are null. In addition for the vlba2
drive, it is not possible change the footage with the feet
or zero parameters.
If vacuum switching is enabled in the sw.ctl control file, the
parameters sent to the recorder will depend on the tape thickness
specified by the most recent label command. If
switching is enabled there is an added restriction that the tape
thickness be must specified with a new label
command before every rec=load command. This is
intended to reduce the likelihood that the incorrect vacuum level
will be set.
Syntax: rec mode=mode,group,roll
Response: rec mode/mode,group,roll,numgroups
Settable Parameters:
mode The string that identifies the mode, 20 characters maximum, a null value is not permitted. No default.
group The group to be recorded, nominally 0-7, but many modes have fewer groups.
roll Roll configuration: on or off.
Default on.
Monitor-only Parameters:
numgroups The number of groups in mode display as the
monitor value.
Comments:
This command selects the recording mode and groups to be used for
an S2 recorder.
Syntax: repro=bypass,trackA,trackB,bandwidth,equalizer
Response: repro/bypass,trackA,trackB,bandwidth,equalizer
Settable parameters:
bypass byp (default) for bypass, raw for read-after-write.
trackA Track for decoder channel A, default 1, 0-28 allowed.
trackB Track for decoder channel B, default 1, 0-28 allowed.
bandwidth Bandwidth for decoding (MHz), default 2.
equalizer Equalizer for reproduce, default same as bandwidth.
Monitor-only parameters: none
Comments:
MAT module functions available for Mark III. For VLBA, the
bandwidth and equalizer are not separately commandable.
The raw mode normally is used only when
checking parity errors on the tape.
Selection of track 0 for a decoder channel will
disable that channel until another track is selected.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses Mark III track numbers.
Syntax: repro=modeA,trackA,trackB,modeB,equA,equB
Response: repro/modeA,trackA,trackB,modeB,equA,equB
Settable parameters:
modeA Reproduce mode for channel A. byp (default) for bypass, raw or read for read (playback).
trackA Track for decoder channel A, default 1, 0-35 allowed.
trackB Track for decoder channel B, default 1, 0-35 allowed.
modeB Reproduce mode for channel B. byp for bypass, raw or read for read (playback). Default is modeA.
equA Equalizer to use for decoding channel A. For VLBA recorders: alt1 (default) for normal speed (135 ips), alt2 for double speed (270 ips), std unspecified. For VLBA2 recorders: std (default) for normal speed (135 ips), alt1 for double speed (270 ips), std unspecified. Additional values of 1, 0.5, and 0.25 (MHz track bandwidth) may be specified for bypass reproduce of these channel bandwidths. For these additional values the monitor value is always the default.
equB Equalizer to use for decoding channel B. For VLBA
recorders: alt1 (default) for normal speed (135
ips), alt2 for double speed (270 ips), std
unspecified. For VLBA2 recorders: std (default)
for normal speed (135 ips), alt1 for double
speed (270 ips), std unspecified. Additional
values of 1, 0.5,
and 0.25 (MHz track bandwidth) may be specified
for bypass reproduce. For these additional values the monitor
value is always the default.
Monitor-only parameters: none
Comments:
The raw or read mode normally
is used only when checking parity errors on the tape. This is also
known as "playback" mode.
This command also sets up the clock recovery chip. The value that
is set depends on the choice of the equA equalizer. The
135 ips equalizer selects a 4 Mb/sec (2 MHz track bandwidth)
set-up. The 270 ips equalizer selects a 8 Mb/sec (4 MHz track
bandwidth) set-up. It is also possible to specify track bandwidths
of 1, 0.5 and 0.25 MHz explicitly for the equalizer to set the
clock recovery chip for the corresponding bit rate. However, for
these bandwidths there is no appropriate equalizer, so the
equalizer itself is set to the default and that value is always
shown for the monitor value (but the command value will be shown
as the value requested).
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses VLBA track numbers.
Syntax: repro=mode,trackA,trackB,equalizer,bitrate
Response: repro/mode,trackA,trackB,equalizer,bitrate
Settable parameters:
mode Reproduce mode, byp (default) for bypass, read or raw for playback.
trackA Track for decoder channel A, between 0 and 35, default 2. For tracks on head stack 2, add 100 to the desired track number. If mode is read, only tracks from head stack 1 may be specified.
trackB Track for decoder channel B, between 0 and 35, default 3. For tracks on head stack 2, add 100 to the desired track number. If mode is read, only tracks from head stack 1 may be specified.
equalizer 0, 1, 2 (default if mode is read), 3 or dis (default if mode is byp) to select the equalizer installed at location 0, 1, 2, or 3 in the recorder. Use 80, 135, 160, 270 to select the equalizer by playback rate according to the following table:
Location 0 test/special
Location 1 135 or 80 ips (normally used for 4 MHz playback)
Location 2 160/270 ips (normally used for 8 MHz playback)
Location 3 disable reproduce (used for bypass mode)
bitrate Clock recovery bit rate, Mb/s. Choices are 16,
8, 4, 2.
Default is the bit rate that corresponds to the selected
equalizer. For equalizer 80 or 135,
default is 4; for equalizers 160
and 270 default is 8. If equalizer
is dis, this parameter is undefined but is set
to have the legal value of 4.
Monitor-only parameters: none
Comments:
This command sets up the reproduce electronics in the tape drive.
MAT module functions available for Mark IV.
Tracks are Mark IV/VLBA track numbers.
The read mode normally is used only when
checking parity errors on the tape.
Bypass mode looks at the output of the write drivers, therefore
it only works if the selected track is enabled and the general
record is on. Use the command st=for,0,on to set
up the write drivers for bypass mode.
If vacuum switching is enabled in the sw.ctl control file, the
vacuum level must established before the repro
command is issued. The vacuum level can be established either by
entering the tape label with the label command
and then loading the tape with the rec=load
command or simply turning off the vacuum with rec=novac.
Please do not try to change the vacuum when the tape is moving.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses Mark IV track numbers.
Examples:
repro=byp,2,3,3,4 #94=+02300302$
#94=.00000034$
repro=byp,16,117 #94=+02305110$
#94=.00000034$
repro=read,26,04 #94=+0000849A$
#94=.00000034$
Syntax: reset=baud
Response: reset/baud
Settable parameters:
baud Baud rate. MATs support 110, 300,
600, 1200, 2400,
4800, and 9600 baud.
Monitor-only parameters: none
Comments:
The old MATs (NRAO only) support 2400 baud
only. Recommended rate is 9600. A system reset
is sent (break character), then the baud rate is changed, then
some U's to synch up the MATs.
Syntax: rw
Response: rw/acknowledgement
Settable Parameters: none
Comments:
The tape is moved in reverse at high speed. For Mark III, the
record bit is disabled and the low tape sensor is turned on. For
VLBA, all track groups are disabled and the low tape sensor is
turned on.
For S2 drives, the selected transports are moved in reverse at
the transport's rewind speed.
For drives other that the S2, the tape is moved at the "schedule"
value as specified in the equip.ctl control file. This is the
speed assumed in the SNAP schedule file for positioning the tape
with the fastr procedure.
Use the srw command and sfastr
procedure for possibly faster tape motion.
Syntax: rx=channel,dcal,box,S,X,K,cal
Response: rx/channel,dcal,box,S,X,K,cal,lostat,value
Settable parameters:
channel Hex value or code word (next page). No default.
dcal Delay cal heater, on (default) or off.
box Box heaters. Turn on with A (default) or B (for the A or B controller), or off.
S,X,K IF amplifier controls, on (default) or off.
cal Noise cal control. May be on, off
(default), oon (Override on), oof
(override off), or external modulation.
Monitor-only parameters:
lostat Status of LO, locked or unlocked.
value Reading in A/D channel shown in first parameter.
Units are appropriate for channel in use.
Comments:
This command is used to control and monitor a standard cryogenic
CDP S/X receiver.
MAT module functions are available.
Channel assignments for the "standard" receiver are on the next
page. Your station's channel assignments are in the rxdef.ctl
file. Details of the MAT protocol are in the MAT
Communications manual.
The mnemonic RX and the receiver's address must be specified in
matad.ctl control file.
Standard Receiver A/D converter channels
channel code volt. Description
# (hex) name Div.
Ratio
00 FRONT 1 Temperature probe: box front
01 REAR 1 Temperature probe: box rear
02 LO 1 Temperature probe: LO
03 DCAL 1 Temperature probe: delay cal
04 INLET 1 Temperature probe: inlet air(after heat)
05 RET 1 Temperature probe: return air
06 SUP 1 Temperature probe: supply air (cold)
07 2.73V 2 -2.73 volt ref. for temperature probes
08 SIF 1 S-band IF power level
09 XIF 1 X-band IF power level
0A KIF 1 Secondary S-band IF power level
0B SLO 1 S-band LO power level
0C XLO 1 X-band LO power level
0D KLO 1 Secondary S-band 2020 MHz LO power level
0E LO5MHZ 1 5 MHz power level to LO
0F 1 spare
10 28V 101 +28 volt power supply voltage
11 24V 101 +24 volt power supply voltage(delay cal)
12 20V 11 +20 volt power supply voltage (LO)
13 15V 11 +15 volt power supply voltage
14 5V 11 + 5 volt power supply
15 -15V 11 -15 volt power supply voltage
16 GROUND 1 ground reference
17 PRES 4.9 dewar pressure
18 X1BIAS 4.9 1st stage X-band FET bias current
19 X2BIAS 4.9 2nd stage X-band FET bias current
1A X3BIAS 4.9 3rd stage X-band FET bias current
1B S1BIAS 4.9 1st stage S-band FET bias current
1C S2BIAS 4.9 2nd stage S-band FET bias current
1D S3BIAS 4.9 3rd stage S-band FET bias current
1E 20K 1 temperature diode, 20K station in dewar
1F 70K 1 temperature diode, 70K station in dewar
Note: This table applies only to standard S/X receivers. Channel
assignments for your station's receiver may be found in control
file rxdef.ctl. Conversion from volts to temperature for channels
0 through 6 is 100 deg C/V.
Syntax: savev=parm1,volts
savev
Response: savev/VrevW,V15rev,V15for,V15scale,V13,V15flip,Vw0,Vw8
Settable parameters:
parm1 Voltage to save, possible values are: vrevw, v15rev, v15for, v15scale, v13, v15flip, vw0, or vw8. No default. clear will delete all saved voltages.
volts The voltage value to save. Default is to use the
current write position for vw0 and vw8,
if the write head has been successfully positioned. For all
others, use the last peaked voltage location from the peak
command. If the write head has not been positioned or the last peak
failed, no value is stored.
Monitor-only parameters:
The first six monitor parameters are read head position voltages
for peak response while reproducing tracks in various
configurations. The table below summaries the parameters and the
configuration: the track used to reproduce, the reproduce tape
orientation, read direction, the direction the track was written
in, and the write head position when the track was written. All
tracks are written with head 15 with the tape in the normal
orientation. (All track numbers are Mark III track numbers.)
Reproduce
Reproduce Tape Read Write Write
Track Orientation Direction Direction Position
VrevW 15 Normal Forward Reverse Vw0
V15rev 15 Normal Reverse Forward Vw0
V15for 15 Normal Forward Forward Vw0
V15scale 15 Normal Forward Forward Vw8
V13 13 Normal Forward Forward Vw0
V15flip 15 Flipped Forward Forward Vw0
The last two parameters are write head position voltages at which
the tracks corresponding to the above read positions were written.
These parameters are not used for VLBA drives.
Vw0 Voltage near tape center
Vw8 Voltage approximately 8 volts toward the deck plate
from Vw0.
Comments:
This command is used to save the voltage positions of the read
and write heads for head calibration. This command is not very
useful by itself. It is designed to facilitate calculation of the
calibration parameters by storing all the values. The hdcalc
command is used to perform the actual calculation. See the Narrow
Track Calibration manual for more information.
The description of the monitor only parameters above is written
assuming odd tracks will be used for both read and write. If odd
tracks are not available, the corresponding even tracks, 16 for
write, 14 and 16 for read can be used instead (note Mark III track
numbers).
The response form of the command will only show values for
voltages that have been successfully saved. This feature is useful
for determining which parameters have not been successfully
measured during automated calibration.
Syntax: schedule=name,start,#lines
Response: schedule/name,line
Settable parameters:
name Name of schedule file to be started. If no directory path is specified, /usr2/sched assumed. If no extension is specified, .snp is assumed. Any currently-executing schedule file is closed, and the new schedule file is opened. If the new file cannot be opened, there will be no schedule active. When a valid schedule is started, a cont command may be necessary.
start Place in the schedule to begin executing. May be one of the following:
null to start with the observation beginning no earlier than 5 minutes from now.
#line for a line number in the file, should be a source command.
time to start with the observation beginning no earlier than this time. time is in standard SNAP format.
#lines Number of lines to execute before automatically
halting. Default is the remainder of the schedule.
Monitor-only parameters:
line The line number to be executed next.
Comments:
If the schedule is started successfully, a log file having the
same name as the schedule is automatically started, and the
procedure file having the same name as the schedule is
automatically established as the schedule procedure library. Any
previously time-scheduled procedures from this library are
cancelled. If a # of lines is specified, an automatic halt
will be issued after execution of these lines. The schedule may
then be continued using the cont command.
Note: If the schedule file is larger than 100,000 lines,
execution will halt after 100,000 lines.
Syntax: sff
Response: sff/acknowledgement
Parameters: none
Comments:
The tape is started moving forward at super high speed. For Mark
III, the record bit is disabled and the low tape sensor is turned
on. For VLBA, all track groups are disabled and the low tape
sensor is turned on.
The tape is moved at the "super" speed value as specified in the
equip.ctl control file. This is the fastest speed that your tape
drive can manage, normally 330 ips.
Use the ff command and fastf
procedure for positioning the tape during a schedule.
Syntax: source=name,ra,dec,epoch,wrap
Response: source/name,ra,dec,epoch,wrap,ranow,decnow,now
Settable parameters:
name Source name, up to 10 characters. No default. Special source names are recognized by many antenna interface programs. Some names and their meaning are:
azel true corrected coordinates
azeluncr encoder units
xy encoder units
Other specialized names are described in the comments below. If name is sun or moon, no position or epoch is required, and if given it will be ignored.
ra Right ascension, in numeric angle/hours format. No default. If name is azel or azeluncr, this parameter is interpreted as an azimuth. If name is xy, this parameter is interpreted as an X position.
dec Declination, in numeric angle/degrees format. No default. If name is azel or azeluncr, this parameter is interpreted as an elevation. If name is xy, this parameter is interpreted as an Y position.
epoch Epoch in years. Default 1950.0. This field is checked only if the specified angles are right ascension and declination. A value of -1 inhibits reduction of coordinates, i.e., they are assumed to be topocentric.
wrap neutral, ccw
(counter-clockwise), cw (clockwise), or null to
indicate which wrap (or no specific one) the antenna should be on
for this source. The local antenna may or may not respect this
parameter.
Monitor-only parameters:
ranow Topocentric right ascension for when the source was commanded
decnow Topocentric declination for when the source was commanded
now Approximate epoch of these coordinates
Comments:
The antenna will begin moving to the new source when this command
is issued. At some antennas, if the source name is given as azel
or azeluncr, then the ra and dec are recognized
as azimuth and elevation in degrees; if the source name is xy,
then the next two fields are recognized as x and y in degrees. If
the source name is sun or moon,
the appropriate coordinates will be calculated by the Field System
based on the current time and the site position as specified in
the location.ctl file.
Issuing a source=... command will invalidate
the calculated values for the fluxn= commands.
To indicate this their values are set to negative numbers.
Typical interpretations of special names may or may not be
supported at any given station. These are typical meanings:
stow Pre-defined stow position.
service Pre-defined service position.
disable Stops antenna communications. This is useful to stop error messages when here is a problem.
idle Monitor the antenna position, but do not command it. This is the normal start-up state for the Field System.
hold Maintain the current antenna position.
The wrap parameter is usually provided by drudg in SNAP schedules
for AZEL antennas for the information of the operator in selecting
the correct wrap for a source when a schedule is started or has to
be re-started. Most antenna interfaces do enforce this.
The topocentric place for sources other than the Sun and Moon is
calculated using USNO's NOVAS routines. As used here, the results
should be accurate to better than 10 milli-arc-seconds for the
time that the source is commanded. The effects of light bending
and diurnal aberration are included. For the effect of diurnal
aberration (typically less than about 0.3 arc-seconds in
magnitude) to be calculated accurately the position of the antenna
in location.ctl must be fairly accurate.
If the input epoch is 2000.0, the input
coordinates are reduced using standard IAU precession and nutation
models, plus light bending and aberration (annual and diurnal) to
yield topocentric coordinates. If the input epoch is 1950.0,
then the input coordinates are rotated to 2000.0 using the inverse
of the rotation used by drudg to rotate from 2000.0 to 1950.0,
then they are reduced to topocentric. In schedules, this has the
effect of making the calculated topocentric place of a source that
has mean coordinates of J2000 in the .drg or .skd schedule file
independent of whether drudg puts 2000.0 or 1950.0 coordinates in
the .snp file (to the precision used by drudg in the .snp) file.
For coordinates of other epochs, the coordinates are assumed to be
apparent (no diurnal aberration) and are reduced back to 2000.0
using the full theory and then reduced to topocentric.
For the Sun and Moon, the topocentric place is calculated to
lower precision than other sources since these are large sources
and are generally only used for calibrating small antennas with
large beams.
Syntax: srw
Response: srw/acknowledgement
Parameters: none
Comments:
The tape is started moving in reverse at super high speed. For
Mark III, the record bit is disabled and the low tape sensor is
turned on. For VLBA, all track groups are disabled and the low
tape sensor is turned on.
The tape is moved at the "super" speed value as specified in the
equip.ctl control file. This is the fastest speed that your tape
drive can manage, normally 330 ips.
Use the rw command and fastr
procedure for positioning the tape during a schedule.
Syntax: st=direction,speed,record
Response: st/direction,speed,record
Settable parameters:
direction for to move tape forward, rev to move in reverse. rev is not permitted for S2 drives. No default, except for S2, which defaults to for. When the tape is stopped, this parameter is displayed in the response as rev for Mark III and IV.
speed Tape speed in inches per second, either nominal or actual. For Mark III & IV and VLBA drives, choices are:
Nominal:3.75 7.5 15 30 60 120 240
Actual: 4.21875 8.4375 16.875 33.75 67.5 135 270
VLBA: 8.33 16.66 33.33 66.66 133.33 266.66
Thin: 5 10 20 40 80 160 320
Mark III & IV and VLBA drives can be commanded to any of these speeds, except Mark III & IV drives cannot use the "VLBA" speeds, VLBA drives cannot be commanded to 3.75 (4.21875) or 320 ips. All of these drives will accept a speed of 0. Note that specifying a "nominal" speed selects the corresponding "actual" speed. No such mapping occurs for "VLBA" and "thin" speeds; there are only actual speeds for these cases. For backward compatibility with an error in an earlier version of the FS, actual value 4.21875 may also be selected by using values 3 and 3.375; 8.4375 may selected using values 7 and 7.875 may still be used. These additional nominal values are deprecated and will be removed in a future version. Since the VLBA drives only have speed resolution of 0.01 ips, the actual speeds are 4.22, 8.44, and 16.88 instead of 4.21875, 8.4375, and 16.875, respectively, but either may be entered in a command.
For S2 drives, the only choices are slp and lp. Also for S2 drives there are additional monitor only values of: sp, unknown, or a reported hex value that doesn't correspond to a known speed.
For Mark III/IV drives the default speed is 120 ips. There is a default speed for VLBA (or VLBA2) drives only when the bit density and form commands have been issued. the default speed is calculated from these commands. No default for S2 drives.
record on to record; off
to disable recording. Default is on. For S2
recorders, record and play are
synonymous with on and off,
respectively. Also for S2 recorders there are additional monitor
only values of rewind, ff, stop, ppause, rpause, cue, review,
notape, and position.
Monitor-only parameters: none
Comments:
The tape is started moving. For Mark III, the record bit is
enabled if record is on. For Mark IV,
the general record bit is enabled and the record bit for each
enabled stack is enabled if record is on.
For VLBA, the track groups are enabled if record is on;
they are disabled if record is off.
For all systems, reproduce mode is not changed and the state of
the low tape sensor is not changed. In the Mark III/IV drives for
Mark III speeds, the rate generator is set to 720 for the "actual"
speed. For "thin" speeds it is set to 853.
For the Mark III/IV drives, the speeds 4.21875
(3.75) and 5 ips do not move
the tape, they implement a "load" function.
For all drives except S2, the vacuum (drive ready for VLBA2
drives) is checked before the command is issued to the recorder.
If the vacuum state (drive state for VLBA2 drives) is not ready,
no further commands are sent. Vacuum (drive ready for VLBA2
drives) is not checked if speed is 0.
A given tape speed of 0 does not move tape but
does enable write heads, thus making bypass mode useful. To see
the time displayed on the decoder front panel while the tape is
stopped, set up the desired reproduce tracks with the repro
command and then issue the command st=for,0,on.
For S2 drives, if the recorder is already recording and a speed
different than what is use is requested, no change will be made
and an error will be reported.
Mark III/IV examples:
st=for,320 #94(>
#94=%80000001$
#94=)F8530000$
st=for,135 #94(>
#94=%80000000$
#94=)E7200000$
st=rev,160 #94(>
#94=%80000001$
#94=)68530000$
st=rev,80,off #94(>
#94=%00000001$
#94=)58530000$
Syntax: stack=cmdMw,cmdMr,calW,calR,woffset
Response: stack/cmdMw,cmdMr,calW,calR,woffset,actMw,actMr,
deltaMw,deltaMr
Settable parameters:
cmdMw Write head stack (stack 1) command position in microns. Default is not to move.
cmdMr Read head stack (stack 2) command position in microns. Default is not to move. May not be specified for VLBA.
calW Write head stack (stack 1) calibration to use: Forward, Reverse, or Uncalibrated. Only the first letter is checked. Default is Uncalibrated.
calR Read head stack (stack 2) calibration to use: Forward, Reverse, or Uncalibrated. Only the first letter is checked. Default is Uncalibrated. May not be specified for VLBA.
woffset Write head type offset. auto
(default) to automatically adjust the head stack positions
according to the write head type parameter in the head.ctl
control file. For none no adjustments are
made. The read head is always adjusted.
Monitor-only parameters:
actMw Actual write head stack (stack 1) position, microns.
actMr Actual read head stack (stack 2) position, microns. Null for VLBA.
deltaMw Difference of actual and commanded position for write head stack (stack 1), microns.
deltaMr Difference of actual and commanded position
for read head stack (stack 2), microns. Null for VLBA.
Comments:
This command is used to position the head stacks in micron
units. An individual head stack may be moved by not specifying
the command position and calibration to use for the other head
stack. For VLBA recorders, only the write head stack parameters
are used; read head stack parameters are reported as null. For
Mark IV, the write parameters refer to head stack 1, read
parameters refer to head stack 2.
The deltam parameters are reported with the sign of
actual minus commanded.
The command positions reported by the lvdt, pass,
and stack commands are consistent. See the
description of the pass command for more
information.
The head stack position in microns is determined by
position = cmdM + absolute offset (Forward calibration)
position = cmdM + absolute offset + for/rev offset (Reverse calibration)
position = cmdM (Uncalibrated)
where cmdM is the commanded position and the absolute
offset and forward/reverse offset are specified
in the head.ctl control file.
If woffset is auto, and the
calibration is Reverse, and the write head
stack is defined as odd in the head.ctl
control file, then an offset of 698.5 microns is added to the
write head stack position.
If woffset is auto, and the
calibration is Forward, and the write head
stack is defined as even in the head.ctl
control file, then an offset of 698.5 microns is subtracted from
the write head stack position.
If woffset is none, no offset is
applied to the write head. The read head is always adjusted.
If the head stacks were last positioned with the pass
or lvdt commands, the response calw
and calr will correctly identify the calibration used.
Odd pass numbers will be reported as forward
calibrations, even passes as reverse
calibrations. Positions commanded with the lvdt
command are uncalibrated.
If the write head stack position is commanded, the auxiliary
data field is set to reflect the commanded position, see the pass
command for more information.
See the Narrow Track Calibration manual.
Syntax: status
Response: display of information
Settable parameters: none
Comments:
A self-explanatory display of information concerning the status
of the current active schedule is listed on the terminal, in the
following format:
Active schedule is: name (name of current schedule)
TIME EVENT
------- ---------
ddd-hh:mm:ss Now
ddd-hh:mm:ss Start of next observation
ddd-hh:mm:ss End of next observation
ddd-hh:mm:ss End of current tape
ddd-hh:mm:ss Start of next tape
Schedule is (not) HALTed
Schedule stream is (not) time-blocked
(until ddd-hh:mm:ss)
Operator stream is (not) time-blocked
(until ddd-hh:mm:ss)
Current line of schedule is:
#nnn copy of current schedule line
Syntax: sy=command
Response: none
Settable parameters:
command The command to be sent to the system.
Comments:
This command is used to execute UNIX systems from within the
Field System. The UNIX command is executed under your default
shell. Any response or error from the command will be displayed
in the Field System Log and Display widow, the response will not
go in the log.
Normally, if you need to execute a UNIX command, use the
operator menu to open a new window temporarily and type your
commands and see the output there. The sy
command should be used only if there is a need for a system
command in a procedure or schedule.
Any valid UNIX command that does not require input may be used.
There is no facility for accepting user input when you use the sy
command.
Since commands could take some time to execute and therefore
tie up the Field System, it is recommended that commands used
with sy be executed in the background. To have
a command run in background and not wait for its completion,
append an & to the command. If you do want
to wait until the command finishes, do not use the &.
Syntax: systracks=st0,st1,st34,st35
Response: systracks/st0,st1,st34,st35
Settable parameters:
stX The recorder track that will have its output from
the formatter placed on recorder track X, where X
is one of the system tracks: 0, 1, 34,
or 35. Default is itself, i.e., for st0 the
default is 0, for st1 the default is 1, for st34
the default is 34, and for st35 the default is 35.
Comments:
This command is used to define what data will be recorded on
the system tracks. This can be used to duplicate data from one
of the normal data tracks if that track has failed. Under Field
System control, the formatter will not normally send any data to
the system tracks, therefore if the default is used for any
parameter's value, normally no data will be written to that
track.
Syntax: tape=lowset,reset
Response: tape/lowsense,footage,fast,capstan,stop,tach,
ready,lcl/rem
Settable parameters:
lowset If off, tape may run off end of reel. If low (default), end of tape will be sensed.
reset reset to reset footage counter
to 0, blank to leave counter alone.
Monitor-only parameters:
lowsense As monitor, this tells whether tape is actually at the low-tape point, i.e. off means not at low-tape.
footage Actual footage counter reading, 5 digits with leading zeroes.
fast Fast tape switch on front panel, fast or nor.
capstan Capstan is moving, or stop has been completed.
stop stop has been issued, or nonstop.
tach Tach is locked or unlocked, i.e. tape is up to speed.
ready Tape drive vacuum is ready or notready.
lcl/rem Switch setting, rem or lcl.
Comments:
MAT module functions available.
Syntax: tape=list
Response: tape/pos0,pos1,pos2,pos3,pos4,pos5,pos6,pos7
Settable parameters:
list One of reset, one position, or
list of eight comma separated positions. Positions are in units
of seconds. unk maybe used to specify a
position as unknown. uns must be used for
transports that are not currently selected in lists of eight
positions. reset is equivalent to specifying
one value of 0.
Monitor-only parameters:
posX The position in units of second for transport X.
unk is displayed for transpoorts with unknown positions. uns is
displayed for drives not currently selected.
Comments:
This command sets ("presets") or reports the position of the
transports. It does not cause the tapes to move.
Syntax: tape=lowset,footage
Response: tape/lowset,footage,lowsense,capstan,tach,ready,
vacuum,chassis,err
Settable Parameters:
lowset low (default) to turn on low tape sensor, off to turn off. Normally this sensor is always left on.
footage If reset, set footage
counter to 0, otherwise set footage counter to footage.
Monitor-only Parameters:
footage Current tape footage counter, 5 digits with leading zeroes. Use the rec command to move the tape to a desired footage or to determine the footage.
lowsense low indicates tape is at the low tape point, otherwise off.
capstan Capstan is moving or stop has been completed.
tach Tach is locked or unlocked, i.e. tape is up to speed.
ready Tape drive vacuum is ready or notready. Null for VLBA2 drives.
vacuum Tape vacuum, inches of water.
chassis Chassis serial number.
error Error flag, hex. okay if no errors, otherwise
the error flag bits represent certain error conditions. Refer to
MCB protocol, word 74 for recorder.
Comments:
This command is analagous to the Mark III tape
command. The footage count as recorded in the log file will be
found in the same location for both Mark III and VLBA systems.
If the drive type specified in the equip.ctl control file is vlba2,
the footage parameter is not supported and the vacuum
parameter is reported as null.
Syntax: tapeform=pass,offset,pass,offset,
...
Response: tapeform/pass,offset,pass,offset, ...
Settable parameters:
pass The pass number whose offset follows, must be between 1 and 100 for Mark III and VLBA, between 1 and 112 for Mark IV.
offset The a priori offset, in microns, for the
preceding pass, must be between 1 and 4000.
Comments:
The passes and offsets must appear in pairs. Multiple commands
are allowed because all of the pairs will not fit on a single
line. The offsets are are used by the pass
command to position the head stack(s) by pass number.
These commands appear in standard procedures named tapeforma,
tapeformb, tapeformc, tapeformd,
one for each recording mode. The appropriate procedure is
invoked in the setup procedure. For example, sx2c1
and sx2c2 invoke tapeformc.
For Mark IV modes, passes for stack 1 should be between 1
and 12. For stack 2 passes, add 100 to
the pass number for stack 1.
Syntax: tapepos=footage
Response: tapepos/footage
Settable parameters:
footage The actual tape footage (as read on the
counter) at which to position the tape.
Comments:
This command starts the tape moving at fast forward or reverse
speed (via an immediate ff or rw
command) and time-schedules an et command such
that the tape will coast to a stop at the requested footage
count (approximately). If the request is less than 100 feet off,
then nothing is done. The model used is:
dt = tacc*0.01 + dfeet/22.5
where
dt time between the ff or rw command and the et command
dfeet number of feet to move
tacc a parameter which accounts for acceleration and
deceleration. The nominal value for tacc is 100, and
is taken from the location.ctl file.
The correct value of tacc can be measured on an
unloaded computer by issuing a tapepos=...
command to position the tape. If the drive overshoots the
command footage by efeet (negative for undershoot),
the corrected value for tacc, rounded to the nearest
integer, is:
taccnew = taccold - efeet/0.225
Tape drives that will not position consistently within a few
feet may require adjustment.
For VLBA recorders, use the rec command.
Syntax: terminate
Response: none
Settabel Parameters: none
Comments:
This is the graceful way to end operation of the Field System.
Schedule execution is ended, log and schedule files are closed,
all programs are removed from the system by oprin.
Syntax: ti
Response: display of list
Settable Parameters: none
Comments:
The current time-scheduled commands are listed on the terminal.
Format:
ts nn @ dddhhmmss command
nn command or procedure index
t type
s : for schedule or ; for operator stream
dddhhmmss time the command will be executed
command the time-scheduled command.
This is a display-only command for debugging purposes.
Syntax: tpi=list
Response: tpi/readings
Settable parameters:
list List of total power integrators to read back.
Standard detector mnemonics allowed.
Monitor-only parameters:
readings List of readings, counts. These values are
stored for use by the tsys1/2/3
and tsysa/b/c/d
commands.
Comments:
For Mark III/IV racks, only USB or LSB total power readings are
accepted; if another total power selection has been set up with
the vc command, the reading is returned as -1.
It is assumed the noise calibration signal is off.
For Mark III/IV racks, the readings are listed from the
selected detectors in the order: VC01-VC14, IF1, IF2, IF3. For
VLBA racks, the readings are listed from the selected detectors
in the order: Lower Side Band: BBC01-BBC14, Upper Side Band:
BBC01-BBC14, IFA, IFB, IFC, IFD.
Syntax: tpical=list
Response: tpical/readings
Settable parameters:
list List of total power integrators to be read back.
Standard detector mnemonics allowed.
Monitor-only parameters:
readings List of readings, counts. These values are
stored for use by the tsys1/2/3
and tsysa/b/c/d
commands.
Comments:
For Mark III/IV racks, only USB or LSB total power readings are
accepted; if another total power selection has been set up with
the vc command, the reading is returned as -1.
It is assumed the noise calibration signal is on.
For Mark III/IV racks, the readings are listed from the
selected detectors in the order: VC01-VC14, IF1, IF2, IF3. For
VLBA racks, the readings are listed from the selected detectors
in the order: Lower Side Band: BBC01-BBC14, Upper Side Band:
BBC01-BBC14, IFA, IFB, IFC, IFD.
Syntax: tpzero=list
Response: tpzero/zero levels
Settable parameters:
list List of modules for which zero levels are to be
measured. Standard detector mnemonics allowed.
Monitor-only parameters:
zero levels List of zero levels, counts. These values
are stored for use by the tsys1/2/3
and tsysa/b/c/d
commands.
Comments:
These zero levels are subtracted from all readings taken on the
same module before system temperatures are computed.
For Mark III/IV racks, only USB or LSB readings are accepted;
if another total power selection has been set up with the vc
command, the reading is returned as -1. It is assumed that the
IF distributor is set for maximum attenuation.
For Mark III/IV racks, the readings are listed from the
selected detectors in the order: VC01-VC14, IF1, IF2, IF3. For
VLBA racks, the readings are listed from the selected detectors
in the order: Lower Side Band: BBC01-BBC14, Upper Side Band:
BBC01-BBC14, IFA, IFB, IFC, IFD.
Syntax: track
Response: tr yy/ddd.hh:mm:ss cmd1 cmd2 delta1 delta2
pr prd1 prd2 praz prel
co cor1 cor2 eqeq refr
Settable Parameters: none
Monitor-only parameters:
The tr line contains information from the tracking computer (all angles are in degrees):
yy/ddd.hh:m:ss year day and time of tracking computer
cmd1 first antenna command angle, x, azimuth, or hour angle
cmd2 second antenna command angle, y, elevation, or declination
delta1 tracking error for first command angle
delta2 tracking error for second command angle
The pr line contains predicted command angles based on time in tr line (all angles are in degrees):
prd1 predicted first command angle
prd2 predicted second command angle
praz predicted azimuth
prel predicted elevation
The co line contains calculated correction information (all angles are in degrees):
cor1 pointing correction for first command angle
cor2 pointing correction for second command angle
eqeq approximate Equation of the Equinoxes, seconds of time
refr refraction correction
Comments:
This command is implemented as a special mode of antcn, which
may not be available at all stations. The format of the output
is station dependent and may differ, some entries may be
missing, and there may be additional entries. This output is
normally produced by antcn and each entry will begin with
#antcn#.
The typical tr line is intended to display information about
the tracking computer. The time, command angles, and deltas
normally all refer to the same epoch and the deltas are
displayed with the sign of command minus actual. The time can be
compared roughly to the time field of the log entry.
The typical pr line contains the command angles and azimuth and
elevation that antcn would have predicted at the time in the tr
line. These angles can be compared to those in tr. If antcn
faithfully replicates the command angle calculation of the
pointing computer, the numbers should agree well. At some
stations this may only be approximate. Some stations may not
have this line if the command angles are calculated in the same
computer as the Field System runs in.
The typical co line contains the pointing corrections that
correspond to the current predicted command angles. The cor1
and cor2 fields are the pointing model corrections for
the two angles. The eqeq field is the equation of the
equinoxes which is a small correction to sidereal time. The refr
value gives the refraction correction for the current command
angles.
Additional lines of locally defined information may be
displayed.
Syntax: trackform=track,sampler,track,sampler,
...
Response: trackform/track,sampler,track,sampler, ...
Settable parameters:
track VLBA or Mark IV recorder track number whose sampler assignment will follow, must be between 2 and 33. For Mark IV add 100 to the track number for stack 2.
sampler For VLBA racks , the sampler that will be mapped to the preceding track, 0, or in the form nnsd, where nn=bbc number (0 through 14), s=sideband ( u or l), d is the data bit (s or m).
For Mark IV racks, the same syntax can be used as for VLBA racks. In addition the nnsd sampler code can have a +m appended, where m is the lag 0, 1, 2, or 3 when fan out is being used.
Comments:
The tracks and samplers must appear in pairs. Multiple commands
are allowed because all of the pairs may not fit on a single
line.The first trackform command after a form=...
command resets all the unspecified tracks to 0.
This command specifies the how the samplers will be assigned in
the next form=... command that uses
either mode m or v. Please
note that although tracks are specified as recorder tracks, this
command assigns the samplers to tracks in the formatter.
The samplers that can be selected are determined by the rack
type specified in the equip.ctl control file. For rack type vlba,
only the first eight BBCs can be used. For rack type vlbag,
up to fourteen BBCs can be used, but only the sign bit is
available. For Mark IV two bits for each of 16 VCs can be used.
For both VLBA and Mark IV racks, only the first track of a VLBA
style fan-out group needs to have a sampler assigned. For a Mark
IV rack, the lags can be assigned to specific tracks. It is an
error to assign a lag that is not generated by the fan mode
selected. This error will be reported when the formmater is
set-up with the form=... command. For
example lag +3 cannot be requested for 1:2
fan-out.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses VLBA or Mark IV track numbers.
Syntax: tracks=list
Response: tracks/list
Settable parameters:
list list of VLBA or Mark IV recorder tracks for which
to enable the corresponding formatter tracks. The tracks may
specified as values of 2-33,
as the VLBA "groups" of tracks not including the system tracks (v0,
v1, v2, v3),
or as the Mark III tracks in with the corresponding VLBA
"groups" (m0, m1, m2,
m3). For Mark IV add 100 to the track number
for stack 2.
Comments:
This command specifies which formatter tracks will be enabled
in the next form=... command that uses either
mode m or v. Please note
that although tracks are specified as recorder tracks, this
command actually enables the corresponding tracks in formatter.
Recorder enables (enable command) must also be
turned on for data to be recorded.
Note that a VLBA or Mark IV track number equals the Mark III
track number plus three. Consequently, odd Mark III tracks are
even VLBA or Mark IV track numbers and vice-versa. See the Track
Assignment Tables in the System Set-up Manual.
Also VLBA group numbers equal Mark III group numbers minus one,
but the VLBA groups include additional tracks. Note that this
command uses VLBA or Mark IV track and group numbers.
Syntax: tsys1=list
tsys2=list
tsys3=list
tsysa=list
tsysb=list
tsysc=list
tsysd=list
Response: tsys1/systemps
tsys2/systemps
tsys3/systemps
tsysa/systemps
tsysb/systemps
tsysc/systemps
tsysd/systemps
Settable parameters:
list List of modules for which Tsys will be computed.
Standard mnemonics allowed.
Monitor-only parameters:
systemps List of system temperatures, computed from
values retrieved by the tpi, tpical,
and tpzero commands. -1.0
means no current measurements available.
Comments:
This command calculates and displays system temperatures for
the different video and IF channels. The command pairs, tsys1/a,
tsys2/b, and tsys3/c
are synonymous. The calculations for the tsys1/2/3
and tsysa/b/c/d
commands use the noise calibration values specified in the caltemp1/2/3
and caltempa/b/c/d
commands, respectively. The formula is:
tsys = (tpi - tpzero) * (caltemp/(tpical-tpi))
tsys system temperature, as reported in tsys command
tpi cal-off reading, from tpi command
tpzero zero-level reading, from tpzero command
tpical cal-on reading, from tpical command
caltemp noise calibration source temperature, from caltemp
command.
For Mark III/IV racks, either USB or LSB system temperature is computed and displayed, depending on the last-measured values for the total power.
For Mark III/IV racks, the readings are listed from the
selected detectors in the order: VC01-VC14, IF1, IF2, IF3. For
VLBA racks, the readings are listed from the selected detectors
in the order: Lower Side Band: BBC01-BBC14, Upper Side Band:
BBC01-BBC14, IFA, IFB, IFC, IFD.
Syntax: upconv=chan1,chan2,chan3
Response: upconv/chan1,chan2,chan3
Settable parameters:
chan1 Upconverter frequency for IF channel 1, MHz. Default 0.
chan2 Upconverter frequency for IF channel 2, MHz. Default 0.
chan3 Upconverter frequency for IF channel 3, MHz.
Default 0.
Monitor-only Parameters: none
Comments:
This command specifies the frequency of the upconverter for
each Mark III channel. Use the lo command to
specify the local oscillator frequencies.
The LO and upconverter frequencies are used by program pcalr
and by the antenna calibration programs. These values along with
the video converter frequencies are used to calculate the phase
calibrator tone frequencies. For Mark III systems, the patch
command should also be used to specify which converters are on
each LO. For Mark III the effect of IF3 is automatically taken
into account, i.e., do not include the value of the IF3 LO in
the upconverter frequency.
Syntax: upconv=chanA,chanB,chanC,chanD
Response: upconv/chanA,chanB,chanC,chanD
Settable parameters:
chanA Upconverter frequency for IF channel A, MHz. Default 0.
chanB Upconverter frequency for IF channel B, MHz. Default 0.
chanC Upconverter frequency for IF channel C, MHz. Default 0.
chanD Upconverter frequency for IF channel D, MHz.
Default 0.
Monitor-only Parameters: none
Comments:
This command specifies the frequency of the upconverter for
each channel. Use the lo command to specify
the local oscillator frequencies.
The LO and upconverter frequencies are used by the antenna
calibration programs.
Syntax: user info=field,label,string,auto
Response: user info/field,label,string
Settable parameters:
field Field number, 1-4. No default.
label field or label, to indicate which to update. Default field.
string An arbitrary string with contents for field or label. No default unless auto is auto and field is 1 or 2, see comments below.
auto auto or literal.
Default literal.
Monitor-only Parameters: none
Comments:
This command sets the specified "User Info" field or label. If
auto is auto, and string is
null, and if field is 1, then field
1 is set to the station name (specified in the location.ctl
control file) or if field is 2, then
field 2 is set to the source name (specified by the source=
command).
The usable length of string for all labels and fields
1 and 2 is 16 characters, for
field 3 it is 32 characters, for field 4
it is 48 characters.
Syntax: vcnn=freq,bandwidth,TPIsel,attenU,attenl
Response: vcnn/freq,bandwidth,TPIsel,attenU,attenl,
rem/lcl,LOlock,TP
Settable parameters:
freq Synthesizer frequency in MHz, value must be less than 500.00 MHz. No default.
bandwidth Final filter bandwidth in MHz, default 2. Choices for Mark III are:
0.125, 0.25, 0.5, 1.0, 2.0, 4.0, 0 (external filter).
Choices for Mark IV are:
0.125, 0.5, 2.0, 4.0, 8.0, 16.0, 0 (external filter).
Value may be integer for bandwidths of 1, 2, 4, 8, or 16 MHz.
May include a trailing parenthesized number. See the comments below.
TPIsel Total power integrator selection. Choices are ul, l, u, if, lo, gr (ground). Default u.
attenU USB attenuator, 0 or 10 db (default) only.
attenL LSB attenuator, 0 or 10
db (default) only.
Monitor-only parameters:
rem/lcl switch setting, rem or lcl.
LOlock LO lock/unlock staus, lock or unlock.
TP total power reading, decimal.
Comments: MAT module functions available.
For Mark IV, the seldom used internal 0.25 and 1 MHz filters
were replaced with 16 and 8 MHz filters, respectively, to
increase the maximum bandwidth.
The bandwidth parameter can include a trailing numeric argument
in parentheses. This argument is not parsed or checked. This
capability is provided so that drudg can include the bandwidth
expected for an external filter (nominal bandwidth 0.0) in the
VC set-up command. This does not control the bandwidth used nor
is it available in the command response. It is intended to
assist the operator in setting up the experiment by identifying
what external filter should be hooked up. It also assists the
VLBA log reading program by identifying what the bandwidth of
the external filter is supposed to be. As an example, to specify
external 2 MHz filters, drudg could specify bandwidth
as 0(2).
Syntax: wakeup
Response: none
Settable Parameters: none
Comments:
This command rings the internal bell on the terminal to alert
the operator. At Haystack and Westford, *ERROR* appears on the
video screen.
Syntax: worm=stack,scale
worm
Response: worm/stack,scale,fo,so,fi,si
Settable parameters:
stack Head stack to measure the speed of, read or 2 (default), or write or 1. Only the first character is checked. Only write is valid for VLBA.
scale Scale to use for speed measurement, update
(default) or new. Only the first character is
checked. The default uses the old scale and updates the speed in
use.
Monitor-only parameters:
fo Fast out speed.
so Slow out speed.
fi Fast in speed.
si Slow in speed.
Comments:
This command measures the inchworm speeds. It must be issued
once with parameters to set it up. Issuing the command without
parameters will start a measurement.
Measurements are made by moving the head stack for 1 second at
slow speeds and 0.1 seconds at fast speeds in each direction.
The before and after voltages are compared and the voltage scale
for that head stack is used to calculate the speed. This scheme
works best if the inchworm starts well away from the limits of
its motion.
Either the current (old) or the new voltage scales can be used.
The old scale is the one most recently read on Field System
start-up from the head.ctl control file. The new scale is the
most recently determined scale factor calculated by the hdcalc
command.
Syntax: wx
Response: wx/temp,press,humid
Settable parameters: none
Monitor-only parameters:
temp current temperature, degrees C.
press current barometric pressure, mbars.
humid current humidity, %.
Comments:
In the standard version of this command, used when the standard
met sensor package is available, temperature, barometric
pressure and relative humidity are automatically read from the
met sensor, displayed at the operator's terminal and written to
the Field System log.
If a nonstandard met package is used, a special
station-specific version of this command may be available.
If no electronic met sensor is available, a manual version of
the command may be implemented. It may prompt for the required
information as follows:
Enter current outdoor temperature (C):
Enter current barometric pressure (mbars):
Enter current humidity (%):
When the manual version of the command is used, the value for
pressure is checked to make sure it's greater than zero, and
humidity is checked to make sure it is between 0 and 100. A wakeup
command should be issued before manual wx when
included in a procedure in order to gain the operator's
attention.
Syntax: xdisp=on/off
Response: none
Settable parameters:
on/off on to turn on extended display, off
(default) to turn off. When off, commands
issued from within procedures are not displayed and ack
responses from modules are not displayed. All responses are
always displayed. When on, all commands and
responses are displayed.
Monitor-only parameters: none
Comments:
Immediate execution operator command.
Syntax: xlog=on/off
Response: none
Settable parameters:
on/off on to turn on extended
logging, off (default) to turn off. When off,
commands issued from within procedures are not logged and ack
responses from modules are not logged. All responses are always
logged. When on, all commands and responses
are logged.
Comments:
Immediate execution operator command.
Syntax: xyoff=xoff,yoff
Response: xyoff/xoff,yoff
Settable parameters:
x offset in X coordinate, in numeric angle/degrees format. Response is in degrees.
y offset in Y coordinate, in numeric angle/degrees
format. Response is in degrees.
Monitor-only parameters: none
Comments:
The antenna will move to the offset position when this command is issued. To return to the on-source position, issue this command with zero offsets.