MDM Trouble Report for 2015 Sep 04

Telescope: 2.4m
Observer(s): Frank (OSU)
Instrument: OSMOS

Problem(s) Encountered:
Changing the disperser, slit, or filter resulted very often in 
complaints about being out-of-position (every fifth or six times
when a change had to be initiated). Luckily, the reset command always 
worked nicely, but the frequency of this happening is 
a bit worrisome.
Below is an example of one of the error messages, resulting also
in a bright red warning sign on the prospero status window
at the appropriate place :


Setting disperser...
 Error: Command returned error
ERROR: DISPERSER DISPERSER=FAULT Mechanism out-of-position, in-position sensor not asserted. Reset DISPERSER to recover
 Error setting the Disperser       
 Programming Error: invalid error code:  -99
 DISPERSER request aborted with errors.
 Execution error in Prospero command.
 Command: disp 2


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Submitted on 2015 Sep 5 [1:21:23]