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Starting and Monitoring IVS sessions on the Hobart 12m

PC Field System

Start the schedule with e.g.


as usual. Then send a start message to IVS.

If in the operations room, start econtrol:

Applications -> AuScope Hobart -> econtrol

Click on the boxes next to “StatusMonitor“ and “Logging and Operator Input”. This should trigger the program to connect to pcfshb and you’ll see a status window and log window. If you don't see any information updating in the status window, type [ctrl]-[shift]-e to start the server process on the field system. You can send PCFS commands and comments from the bottom of the log window. Note you won’t see the log window update until the next scheduled command is sent.

During the experiment, the following checks can be made. Please log them using the new Checklist GUI rather than the paper checklist:

Please go through the checklist as often as you like but at least once every 2 hours. Below is an explanation of the current list of items to check during an observation:

  • HMI: Antenna drives OK
    Check the antenna status display in HMI on the Windows PC (to view it, start a VNC session via the Applications menu to timehb). If DRIVES STATUS, SOFT LIMITS, DEMAND LIMITING and HARD LIMITS are all green then all is well.
  • HMI: Time OK (i.e. SNTP server OK)
    Check the antenna status display in HMI on the Windows PC (to view it, start a VNC session via the Applications menu to timehb). If the CURRENT TIME area reports SNTP SERVER OK, then the controller knows the time. If not, the antenna probably doesn't know where its pointing, there's a problem.
  • Antenna on source and tracking
    In econtrol, type onsource and check the antenna is tracking, which it should be provided a new source command hasn't recently been issued.
  • Autocorrelations OK
    At the end of every scan, the postob procedure will run a script to extract some Mark5 data and display the autocorrelations of the 16 channels in the PCFS VNC session. Good data should contain quite flat bandpasses and zero phase. See autocorrelation spectra plots for an example and what problems to look out for. If there's a problem, the DBBC may need reconfiguring.
  • delays OK, stable and within 1us (clkoff, maserdelay)
    In the econtrol, issue the commands clkoff and maserdelay. These values should be within 0.5 microsecond of each other and stable (i.e. similar results if you issue the commands again). The monitoring software will calculate the difference for you and should ring an alarm if the difference is not acceptable. See this entry in the common Problems section for a remedy.
  • Maser status OK
    Check the “Standard VCH-1005A Manager” display on the Windows PC (to view it, start a VNC session via the Applications menu to timehb). Green numbers are good, red are bad. Here's an example of how it should look:

    Report any red numbers to Brett ASAP. if you see mention of 'Battery', the maser has lost mains power and is running on it's UPS. If so, tell Brett immediately.
  • mk5=mode? correct
    Check mode with this command in econtrol: mk5=mode?. The result should be
    /mk5/!mode? 0 : ext : 0x55555555 : 2 : 2 ; for R1 and R4 experiments,
    /mk5/!mode? 0 : ext : 0x55555555 : 4 : 2 ; for OHIG, APSG and CRF observations.
  • mk5=dot? response nominal
    This is a check of the Mark5 decoder time. Check the time offset in the formatter with this command in econtrol:mk5=dot?. Make sure it reports a small offset (~<10ms) as the final value, that syncerr_eq_0 and that FHG_on or FHG_off depending on whether it is currently recording or not.
  • disk_pos OK
    The command disk_pos in econtrol should report three values - the current number of btyes recorded, bytes at start of previous scan and bytes at start of current scan. If not currently recording, the first and third values should agree. It is normal for Yarragadee disk_pos to lag its expected value due to regular stows for USN uplinks.
  • Weather (wth) being logged
    Look through recent messages in the field system log for output from the wth command, which will look like this:\\/#wx#/16.1,1007.9,58.6\\Also make a note in the log of present weather conditions (if you're at the observatory).
  • S-band Tsys OK (~15-17)
    Check recent output from a systemp12 command (don't execute it unless the Mark5 is NOT recording) to see is the S-band Tsys is within the expected range: about 15 to 17 cal units. Look for “tsysS” in the log. Make a note in the log if it is outside this range. If it persists, or the values vary wildly, there may be a problem.
  • X-band Tsys OK (~5-7)
    Check recent output from a systemp12 command (don't execute it unless the Mark5 is NOT recording) to see is the X-band Tsys is within the expected range: about 5 to 7 cal units. Look for “tsysS” in the log. Make a note in the log if it is outside this range. If it persists, or the values vary wildly, there may be a problem.
  • Any problems or concerns logged
    If there are any other issues or unusual behaviour, report it in the log by typing a comment preceeded by double quotes in econtrol
  • Field System time (monit2) agrees with station time
    Compare the clock shown in the monit2 display in the PCFS VNC session with the station clock (if you're at the observatory) or with the TAC32 GPS clock in the Tac32Plus display on the Windows PC (to view it, start a VNC session via the Applications menu to timehb). The seconds should tick over together. If they don't, the clocks probably need synchronizing. To run the monit2 status monitor, enter this command at the pcfshb prompt in the VNC session
    /usr/bin/xterm -name monit2 -e /usr2/fs/bin/monit2

Common problems

Formatter to FS time offset

You might get a

ERROR sc  -13 setcl: formatter to FS time difference 0.5 seconds or greater 

to fix this do a:

sy=run setcl offset

Note this error is likely to reappear regularly.

Note also that the error message

?ERROR sc  -18 setcl: program is already running, try "run setcl" instead.

has been seen recently when the command is issued from a terminal window. The problem has not been seen when the command is entered into the oprin window. If you do get this error when entering the command into the oprin window, please tell Jim.

FS time is out by several seconds

The origin of this problem is presently unknown but the FS time can get seriously out of step. To fix this, while not recording start the fmset program from an oper@pcfshb terminal and issue the ”+” and “-” commands, then quit from fmset (ESC). Restart fmset and the FS time should now be correct. You may need to resync the mark5B pps after this procedure.

Be sure to check that FHG=off. Sometimes if there is a power glitch while the Mark5 is still recording, it can get 'stuck' in record mode. This will need to be stopped with disk_record=off, then run fmset again.

clkoff reading is drifting or far from the maser-GPS offset

The clkoff command measures the difference in the 1 PPS (pulse per second) signal coming from the GPS with the 1PPS from the Mark5. The Mark5 1PPS has travelled through both the DBBC and Mark5 and is a good diagnostic of a timing problem in our hardware.

There are occasionally timing glitches (clock jumps) that cause the clkoff value to change. There are several possible causes:

  1. Spurious signals on the 1 PPS signal. For example at Yarragadee we sometimes see a clock jump when the antenna drives are powered on. We also sometimes see it as a result of poor earthing or a bad connection in the cable between the DBBC or Mark5
  2. DBBC problem. Sometimes the DBBC (which uses the 1PPS from the maser and passes it's timing on to the Mark5) can become unstable and the 1PPS signal will start to drift.

The easiest way to check for clock stability is to compare the clkoff and maserdelay values. The difference between these two should remain stable at around 0.3 us. The Log Monitor software calculates the difference and logs it as the “Delay difference”. If this value exceeds abs(0.5) us, an alarm is sounded (by default).

So what do I do if there's a clock jump?

The first thing to do is not panic. If the new delay remains constant and less than abs(20) us, the correlator can handle it. Re-setting the delay introduces another clock jump which makes the correlation more difficult. So the first thing to do is in the Log Monitor:

  1. Press “Acknowledge alarm”
  2. Under the “Configure” menu, select either:
    1. “Delay monitoring → Audible warning” which will make the monitor software beep every time it sees a > abs(0.5) us offset, rather than sound the alarm, or…
    2. “Delay monitoring → Silent warning” which will log that the offset is large but not beep or ring alarms. This should be used with caution!
  3. Now monitor the Delay difference and see if it has stabilised. You can do this in several ways:
    1. Watch the Delay difference values in the log monitor window. You can get more frequent updates by issuing regular clkoff and maserdelay commands from e-RemoteCtrl
    2. Get Log Monitor to extract a history of the delay and delay difference values by pressing the “Export Data” button. When you do this, several ascii files will be written to /vlbobs/ivs/logs. The file that will be of most interest is (e.g. for Yarragadee) /vlbobs/ivs/logs/yg_ddif.txt. You can open this file and read it's contents, or you can use a plotting program like gnuplot to plot the values. This is especially useful if you want to see if the new offset is stable or not:
      1. from a terminal window:
        cd /vlbobs/ivs/logs
        plot 'yg_ddif.txt' u linesp

        This will plot the delay difference against day number. You can use the right mouse button in the plot window to zoom in. Every time you press “Export data” the output files are refreshed and you can replot the values in gnuplot either by typing 'replot' or by pressing the “Replot” button in the plot window. Other possible useful files to plot are yg_maser2gps.txt, the difference between the maser and GPS 1PPS, and yg_fmout.txt, the difference between GPS and Mark5 output 1PPS.

      2. Seperate windows [0|1|2] can be opened for each station by replacing the final command above with:
        set terminal 'wxt' 2; plot 'yg_ddif.txt'

So when do I need to reconfigure the DBBC, run fmset etc?

If the delay difference is stable you don't need to do anything.

If the delay difference is more than 20 us, or gets so large that the clkoff or maserdelay values lose precision, run fmset to get the delays back to something manageable. Make sure you are not recording while running fmset! Issuing a halt command from e-RemoteCtrl followed by disk_record=off is usually a safe method.

The first thing to do is try the command


in e-RemoteCtrl. Check to see if this worked by typing clkoff and maserdelay. If this doesn't fix it, proceed with the steps below.

If the delay difference is drifting (usually linearly), the DBBC probably needs reconfiguring. This can be done from e-RemoteCtrl as follows (again, best to halt the schedule and make sure you're not recording):


Monitor how things are going in the DBBC VNC session. A reconfig takes about 2 minutes. When it's completed, synchronise the dbbc:


Then in a terminal window on pcfs[hb|ke|yg], run fmset to get the clocks lined up.

Now resume observations with a cont or schedule= command.

PCFS log window reports problem with

This occurs when communication with the power sensor (a USB device) in the IF rack is lost. The power sensor is required for System Temperature (Tsys) measurements. The solution is to cycle power to the sensor by unplugging it's USB connection into the Field System PC and then plugging it back in again. If you are not at the site, and cannot contact anyone on-site to fix it, you can disable the Tsys measurements as follows:

On pcfshb:

pfmed: pf,station
pfmed: ed,systemp12

An editor will start. Comment out the command by putting a double-quote at the start of the line. It should then look like this:

"sy=/usr2/oper/ &

Now exit the editor, and

pfmed: exit

Lastly, please make a note in the log that Tsys measurements have been disabled.

It is possible to remotely reset the power sensor at both Yarragadee and Hobart. You should first follow the procedure outlines above, then kill any remaining or processes running on pcfsyg/pcfshb (use ps -ef | grep ReadPower to identify the process IDs). Become root with su and issue the command

/etc/init.d/AgilentU2000 restart

It will run a series of procedures to toggle the power and then try to re-establish communications. It may take two tries to get it fully working - when it is ok, you should get a blithely cheery message to this effect, and be wished good luck. When you receive this message, wait for a break in the recording and test the power sensor by running /home/oper/ All being well, there should be no timeouts although the measured power is likely to be nonsensical (there will be bogus values written into the data from the previous timeouts). If it fails with timeouts, persevere with the /etc/init.d/AgilentU2000 restart procedure. Once you have it working, repeat the pfmed process and remove the comment from the systemp12 procedure.

Antenna off source and not moving in Azimuth

Currently there’s a fault that sometimes develops in the Hobart 12m drives (or the control software) that causes the antenna to stop moving in Azimuth. If this happens the station alarm should sound and the PC Field system will report an error like this:


You will also notice that the antenna control/monitoring GUI (called HMI) on the Windows PC will show constant azimuth position, and probably the Azimuth brakes on. You can see this display by starting up a VNC session to timehb.

To fix this problem, click on “Reboot System”, then either wait for the schedule to send the antenna to the next source, or look back through the schedule and re-issue the last “source=…” command. (Note the ‘onsource’ command doesn’t seem to remedy the problem at the moment. Check the snap file for the syntax of the command & the most recent usage). The “Reboot System” button is shown here:

The above screenshot shows the antenna in a healthy state. You will see various boxes in the POWER and DRIVES STATUS areas go red when there’s a problem.

If econtrol gets closed during an observation

Recording continues as econtrol is a front-end viewer for the field system, so don't panic :)

When you restart econtrol from the menu it may be unable to load the telescope information (the drop-down menu boxes), and the terminal from which econtrol runs produces “Can't open interface” type errors. If this happens, in the econtrol window (the green one, not the terminal) press Control+shift+e, and then try to open one of the drop down boxes again - this time the icon in the bottom right corner should go from red through 'connecting' to green, the information will now load, and observing can continue as normal.

/home/www/auscope/opswiki/data/pages/operations/monitoring_hb.txt · Last modified: 2014/12/17 09:53 by Warren Hankey