ALFALFA Survey - Troubleshooting for a2010 Observations     Last update April 19, 2008

alfadatawin problems

• The Problem: When observing remotely you can't display data using alfadatawin.
• What To Do: Someone may have left the process running on dataview; check processes running on dataview (ps -ecf); if the alfa_data_grabber is running and owned by someone else (e.g. the previous observer), that's the problem. Call Mikael and ask him to kill the process.
• Reported On: 05/04/02, 08/04/18

Correlator Configuration

• The Problem: CIMA asks: "Correlator Configuration changed since last apply, continue?" when you attempt to begin observing.
• What To Do: Do not continue. Go back and hit "Configure WAPP ALFA" again. Either you did not configure the WAPPs or you hit the button too fast for CIMA to register the command. In the future, make sure CIMA reports back after pressing each button so you know the command was sent.
• Reported On: 05/05/12

Frequency Axis Scale Problem

• The Problem: You notice that the frequency scale on the waterfall plots suddenly switches from center 1385 MHz, range 1335-1435 Mhz, to some other range in one or more beams. This is due to a glitch in the WAPPs.
• What To Do: Continue observing. The frequency range should return to normal in the next drift. However you will have to correct the fits file with the incorrect frequency scale. To do this, copy the affected file somewhere else. Use the program fv to edit the affected parameters: CRVAL1 should be 1385000000.00, UPPERSB should be 0, and correct the sign of CDELT1 (see note from Mikael in log061101.) The easiest way to correct these parameters is to open the file in fv, click on ALL and then use the Calculate function to set the parameters. Run filecreator on the new file and replace .sav files generated from the original file.
• Reported On: 061101, 061209, 070328

Internal RFI

• The Problem: You notice a lot of strong RFI at unexpected frequencies.
• What To Do: A transmitter may have been left on in the dome. Check Rack 3 in the control room if you think this may be happening. Make sure the light in the top/middle of the bottom panel is off.
• Reported On: 05/05/18

Network Failure

• The Problem: When observing remotely, you lose connection with AO.
• What To Do: Wait to regain connection and start over. If you abort an observation, be sure to create a new fits file before beginning again.
• Reported On: 05/06/04

VNC Sessions Die

• The Problem: When connected via VNC from a remote site, VNC connection would drop. This occurred on a connection from Union College and is diagnosed as a local problem by Arun; see note below.
• What To Do:

  Checking the logins on `remote' I find:
   # last -10 a2010
   a2010     pts/10       adjuntas.astro.c Fri Mar  7 16:07 - 16:12  (00:05)
   a2010     pts/14       isp1-acad-nat1.u Fri Mar  7 15:13 - 15:14  (00:00)
   a2010     pts/11       isp2-acad-nat1.u Fri Mar  7 14:41 - 15:41  (01:00)
   a2010     pts/10       isp2-acad-nat1.u Fri Mar  7 14:34 - 15:18  (00:44)
   a2010     pts/12       isp1-acad-nat1.u Fri Mar  7 12:30 - 13:38  (01:08)
   a2010     pts/14       isp1-acad-nat1.u Fri Mar  7 12:28 - 13:37  (01:08)
   a2010     pts/13       isp2-acad-nat1.u Fri Mar  7 12:17   still logged in
   a2010     pts/12       caborojo.astro.c Fri Mar  7 12:16 - 12:28  (00:12)
   a2010     pts/11       isp2-acad-nat1.u Fri Mar  7 12:10 - 14:19  (02:08)
   a2010     pts/8        isp2-acad-nat1.u Fri Mar  7 11:15 - 11:48  (00:32)
  
   Presumably the `isp[12]-acad-nat1.u[nion.edu]' logins are yours.
   The names suggest that your Internet Service Provider (ISP) is using
   a translated ("NAT") network address for your external access.  This is
   usually implemented on a perimeter router, which could get overloaded
   if there are too few address translations available in the pool.  It
   may be worthwhile to check with your network people if this is happening,
   and perhaps get them to increase the size of the NAT pool.
  
   Regards,
   -arun
  Reported On: 08/03/07
  
  

No Data

• The Problem: The telescope monitoring windows report that data is being taken, but your data files are empty.
• What To Do: Make sure you have control of the telescope. The telescope operator may have pointed the telescope for you and then not given you back control. If you abort an observation, be sure to create a new fits file before beginning again.
• Reported On:

Power - Switching power from emergency generator to commercial

• The Problem: The telescope operator warns you that power will be switched from emergency generator to commercial. You lose pointing for a few seconds during the switch.
• What To Do: You will lose the 10-minute drift during which the power is switched. You may not have to restart CIMA if everything (power levels, tracking, pointing) looks normal after the switch.
• Reported On: 05/06/01

Power - Rising Power Levels

• The Problem: The power levels displayed for each beam and each polarization should remain blue. For the power levels to occasionally flicker orange is normal. But the power levels may begin to rise in one or more beam and continue rising.
• What To Do: Abort the observation, adjust power, and begin the observation again. If you abort an observation, be sure to create a new fits file before beginning again.
• Reported On: 05/05/20

Strong RFI at 1367 and 1382 MHz

• The Problem: You notice strong RFI at 1367 and 1382 MHz frequencies.
• What To Do: The radar at Punta Salinas naval base has been mistakenly left on (see this link.) Tell the telescope operator to call Punta Salinas and tell them to turn off their equipment.
• Reported On: 06/16/10

Swap Space

• The Problem: CIMA reports that observer2 is out of swap space.
• What To Do: Report the problem to Arun and wait until he has made more space.
• Reported On: 05/04/10

VLBI Warning

• The Problem: CIMA says:''WARN VLBI control initialized'' at the beginning of a run.
• What To Do: Nothing. So far we have not noticed a problem when this occurs. Emmanuel assures us everything is okay.
• Reported On: 05/06/12, 05/02/26

WAPP chip error

• The Problem: CIMA says one of several things:
  • WARN wappdata buildup logic error
  • WARN WAPPDATA confused cleared n dumps
  • WAPP(1) ERROR counts don't match for chip n
  • ERROR spectral line, read data error
• What To Do: Abort your observation, exit CIMA and start over. Be sure to restart the WAPPs. If you abort an observation, be sure to create a new fits file before beginning again. Often this will fix the problem, but sometimes nothing can be done to "unconfuse" the WAPPs (as on 05/05/09). Giacomo replaced board on WAPP 3 in an attempt to fix the WAPP problem on 05/05/05. As reflected in the dates below, this problem was much more frequent in the past than it is now.
• 2008 Update:   There are now warning messages which appear in orange and are not fatal. Keep an eye on the waterfall plots; if the beams all appear to be there, then probably everything is ok. Abort and restart only if beams disappear or you are uncertain. If you want to check records in a FITS file, you can follow the instructions on checking FITS records in IDL.
• Reported On: 05/08/17,05/06/08, 05/05/31, 05/05/10, 05/05/09, 05/05/05, 05/04/09, 05/04/02, 05/03/28, 05/03/26, 05/03/22, 05/03/21p, 05/03/20, 05/02/26, 05/02/25, 05/02/21, 05/02/20, 05/02/18, 05/02/16, 05/02/14a and many, many other dates

WAPP not running

• The Problem: CIMA says: WAPP not running
• What To Do: Abort observation, restart the WAPPs, adjust power, and start a new fits file. Then begin observing again. If you abort an observation, be sure to create a new fits file before beginning again.
• Reported On: 05/04/02

WAPPs won't adjust power

• The Problem: One or more of the WAPPs fail to adjust power when you hit "Adjust Power". CIMA gets hung: WARN: Executive is busy, waiting WAPP adjust power
• What To Do: You need to do more than simply restart the WAPPs. Restart the executive, reapply the IF/LO setup, restart the WAPPs, configure WAPP ALFA and adjust power.
• Reported On: 05/02/16

Waterfall plots won't show up

• The Problem: The waterfall plots at AO show no data even though the telescope monitoring windows report datqa is being taken.
• What To Do: The data may be there, even if the waterfall plots aren't showing it. Check the fits files directly. The waterfall plots work best if they are started up after the observations begin. You may have to restart them in the middle of a run if they stop showing data.
• Reported On: 05/05/22