Page Comparison

...

Traceback (most recent call last):
    File "/home/sashab/Documents/sashas_python_scripts/pixis/ConvertPIXISRawToFits.py", line 143, in <module>
        convertRawToFits(source_file, target_file, source_dir = source_dir, target_dir = target_dir, target_suffix = target_suffix, header_elems_to_add = additional_header_elems); 
    File "/home/sashab/Documents/sashas_python_scripts/pixis/ConvertPIXISRawToFits.py", line 49, in convertRawToFits
        flat_img_arrays = [struct.unpack(img_fmt, data_set) for data_set in separated_data]
    File "/home/sashab/Documents/sashas_python_scripts/pixis/ConvertPIXISRawToFits.py", line 49, in <listcomp>
        flat_img_arrays = [struct.unpack(img_fmt, data_set) for data_set in separated_data]
struct.error: unpack requires a buffer of 2097152 bytes

OTHER SIGNS OF ERROR: 

• Identified instrument is a Demo: 
  • (Something like): PIXIS: 100B (SN:12345:Demo) [E2V 1340 x 100 (CCD 36)(B)]
• Temperature set point is -40 degrees C: 
  • (Something Like): Temperature is -40 degrees C

SOURCE OF PROBLEM:

 The computer cannot connect to the camera, and is therefore generating data off of the 'Demo' PIXIS instrument.  This artificial image does not conform to the format expected by the code that converts the .raw image to a .fits image, and the code fails with the above error. 

...

• Make sure that camera AC-DC converter (black, labeled PIXIS Camera) is turned on (switch is flipped to | rather than 0). 
  • Power strip has a green light to indicate it is turned on, though it is covered by black aluminum tape.  You can peel back the tape to check, if you like. 
• Make sure USB connecting computer to camera is plugged in at both ends (perhaps give the ends an extra push to make sure they are connected).
• Make sure camera power cord is connected to the camera. 

PROBLEM: When attempting to move stage, system throws an error like: 

Traceback (most recent call last):
    File "/home/sashab/Documents/sashas_python_scripts/pixis/moveStageToFocusPosition.py", line 22, in <module>
        zaber_stage.home( )
    File "/home/sashab/anaconda3/lib/python3.7/site-packages/zaber_motion/binary/device.py", line 323, in home
        call("binary/device/home", request, response)
    File "/home/sashab/anaconda3/lib/python3.7/site-packages/zaber_motion/call.py", line 46, in call
        process_response(response_buffers, response_data)
    File "/home/sashab/anaconda3/lib/python3.7/site-packages/zaber_motion/call.py", line 122, in process_response
        raise convert_exception(response_proto.error_type, response_proto.error_message, response_buffers[1])
zaber_motion.exceptions.binary_command_failed_exception.BinaryCommandFailedException: BinaryCommandFailedException: Command 1 with data 0 resulted in error code 1.

OTHER SIGNS OF ERROR: 

• Zaber translation stage does not move, so focus does not change even when different focus values are given (with the -f command line option)

SOURCE OF PROBLEM:

 The computer is having some issue passing commands to the translation stage.  It can connect to the stage, but the stage will not accept commands. 

POSSIBLE SOLUTION(S): 

Either the connection between the stage and the computer needs to be reset or the stage is otherwise occupied

To reset the stage connection, try the following (in sequence): 

1. Disconnect and reconnect the USB, pausing for about 10 seconds before reconnecting
   1. Grey USB cord, at time of this writing 
   2. Did this solve the problem?  If so, stop here.  If not, next step. 
2. Disconnect and reconnect the stage power, pausing for about 10 seconds before reconnecting 
   1. Either look for AC-DC converter labeled 'zaber' on the powerstrip
   2. Or open up OSELOTS and unplug from stage gearbox (center of spectrograph base) 
   3. Did this solve the problem?  If so, stop here.  If not, next step. 
3. Reboot control computer. 

If none of the above work, the stage may be under some other motion control.  Most likely, the manual knob to move the stage is not perfectly centered 

1. Open OSELOTS and locate the knob on the zaber translation stage gearbox 
2. Turn the knob to move the stage to approximately halfway along its control axis 
3. Center the knob until the stage is still
   1. There is a slight catch at the knob center position, but it is very subtle
   2. The stage can appear still, but in fact still be slightly engaged.  Watch the stage for at least 30 seconds to make sure it is truly still 
4. Now that stage is not moving due to its internal motion control, it should be controllable over USB once again. 

PROBLEM: Translation stage slipping 

OTHER SIGNS OF ERROR: 

• Two images taken with same focus position do not show same focus results
• Two images with similar but not identical focus positions show focus results that appear identical 
• If the stage is watched while moving, wormgear rotates, but stage does not move smoothly or does not move at all
  • Occurs most obviously when the stage is moving AWAY from home, rather than towards home 

SOURCE OF PROBLEM:

 The internal gears of the translation stage have lost good contact.  This often happens after OSELOTS has been transported (vibrations loosening the screw connections)

POSSIBLE SOLUTION(S): 

 Thankfully, a typically easy fix. 

1. Find the smallest hex key in the OSELOTS toolkit. 
2. Locate the small hex-hole on the top of the stage (the threaded part on which the focusing lens is mounted) 
3. Tighten this screw until it is firm (over-tightening should not be necessary) 
4. Repeat stage motion test, and verify that stage moves smoothly to and (especially) away from home. 

PROBLEM: Acquired images show very little or no light, particularly noticeable with calibration light sources: 

Here is an example of such an image (right panel of Figure below), taken with the HG-2 calibration light source.  Notice how the lines in the right panel are very ragged; not the clean image of the fiber tip, as seen through the slit, that we hope for (left panel): 

OTHER SIGNS OF ERROR: 

Images taken of the sky show little or no light, although all connections are good and the lens is on sky. 

...

If the system is not working, the light shining through the slit will be either non-existent, very faint, and/or ragged. 

SOURCE OF PROBLEM:

The multimode optical fiber and the 5 um slit have slipped out of alignment.  OSELOTS requires manual realignment. 

POSSIBLE SOLUTION(S): 

Be warned, this is a ~1 hour process.  We are working on designing a more user-friendly repair process.  At no point in this process should the fiber be removed from Here are the steps (somewhat difficult to describe in text): 

...