Caltech Submillimeter Observatory

Caltech Submillimeter Observatory Office,  111 Nowelo St., Hilo, Hawai'i 96720  Voice: (808) 935-1909 Fax: (808) 961-6273

Trouble Shooting

No Signal

Check

• Is everything on (SHARC dewar switch, gain 8000, A/D switch, Pre-amp switch, SHARC panel switches)?
• Is Beam-path unobscured (mirror covers, tertiary mirror)?


If all seems OK, start an OTF integration (say 'otf 300 2 2 2 2 2') go out to platform and wave hand in the SHARC beam. See if you see signal on the OTF strip chart as a result.

YES: SHARC is working. Possible promlems: SHARC warming up, badly mispointed, or source is really too faint for weather. To check if it is a warm-up problem, reconnect Lakeshore cable, and check thermistor. Reading should be >5000kOhms. If reading is less, call for help on what might be done...
 
NO: Either something is not connected (e.g. optical fibres), or SHARC is warmed up completely. To check for warm-up see above.

Frozen Integration.

1. Stop SHARC server on Mac (STOP button).
2. CRTL-Y in UIP, then type 'exit' at prompt.
3. (Optional, in case it fails without), clean up old SHARC processes on alpha1. (see instructions)
4. Start UIP.
5. Start SHARC server on Mac (left-arrow button)
6. Reissue Initialization Commands (see instructions)
7. Need to open a new datafile. Anything written to the old file beyond this point will likely be unreadable.

Antenna Computer Freeze

In the UIP type 'ant /nosync' to reboot antenna computer. If fails, exit UIP (ctrl-Y), and try again. If still unsuccessful it may be the backend causing the trouble. Reboot Backend.