Troubleshooting An Overheating PXL Camera

All the error messages described in this page will be seen by the OA, not by the observer. Also, all the actions described here must be taken by the OA. These actions will probably require an interruption of observing to get the PXL camera working again.

The original source of this information is Nightlog Ticket K2-04864.

1. The Symptoms
2. The Solution
3. Discussion

1. The Symptoms

   The OA sees a number of error messages appearing on his or her console, generated by the waimanu cam_server program:

   waimanu cam_server [pid]: pxl current temp too warm [T]

   where [T] is number. NOTE that the number given as [T] must be divided by 100 to get the actual temperature of the camera in degrees C.

   NOTE also that the normal temperature set point for the NIRSPEC PXL camera is -25C.

2. The Solution

   When this problem occurs, the OA should take the following actions:

   1. Kill the XGuide or kcamtest software.
   2. Go up to the instrument, and go around to the right side of the instrument as viewed from the back (i.e., the right as you stand at the back of the instrument looking in towards the tertiary mirror).
   3. Remove the short middle insulation cover to gain access to the PXL CEU2 controller box.
   4. On the CEU2 controller box, there is a square button that should normally be illuminated green, and an LCD display that gives the temperature.
   5. If the button is red, note what the LCD display says then hit the button to reset the camera.
   6. If the button returns to green, wait and watch the LCD screen. After a few moments, the temperature should gradually begin to drop towards the setpoint of -25C.
   7. Watch it for a minute or so to verify that it is dropping, then replace the insulation cover and go back to a warmer place.
   8. NOTE: If at any point in the procedure the controller is not behaving as described above, call Rich Matsuda for further directions.

3. Discussion

   This type of problem has been reported twice. These problems are most likely due to some stuck bit or serial communications glitch between the controller and the camera. Resetting the controller as described has cleared the problem both times.

   Note that this type of problem, and these error messages from the cam_server, are not due to a glycol flow problem. However, it is still a good idea to check the glycol flow, just to eliminate that as a possible additional problem.

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   Last modified: 22 December 2000