Shane AO  

Problem: Illegal Value

Manifestation:

• Failure during progression of script:

  user@shimmy:∼/u/user/observers/lgs/saocon_setups/seeing-logging.sh

  of the form:

   
     Exception in thread Data timer: 
     Traceback (most recent call last): 
     File "/usr/lib64/python2.6/threading.py", line 532, in __bootstrap_inner 
     self.run() 
     File "/usr/lib64/python2.6/threading.py", line 736, in run 
     self.function(*self.args, **self.kwargs) 
     File "/usr/local/lick/lib/python/scripts.py", line 346, in save_data 
     shaneao.self.save_data(shaneao.state) 
     File "/usr/local/lick/lib/python/rtc.py", line 651, in save_data 
     hdu.header.append((keyword,value,key)) 
     File "/usr/local/lick/lib/python/pyfits-3.2.4-py2.6-linux-x86_64.egg/pyfits/header.py", line 1194, in append 
     card = Card(*card) 
     File "/usr/local/lick/lib/python/pyfits-3.2.4-py2.6-linux-x86_64.egg/pyfits/card.py", line 443, in __init__ 
     self.value = value 
     File "/usr/local/lick/lib/python/pyfits-3.2.4-py2.6-linux-x86_64.egg/pyfits/card.py", line 564, in value 
     raise ValueError('Illegal value: %r.' % value) 
     ValueError: Illegal value: [48, 39]. 
     

• Failure in response to "Actions... Save telemetry data...", or its equivalent command: data(), which similarly complains of:

   
     ValueError: Illegal value: [48, 39] 
     

Solution/Recovery:

• Exit the script (if it has not already done so).

• Stop shaneao software. In ShaneAO terminal:

  >>> exit()

• Re-start shaneao software: From VNC background pull-down menu, select:

  shaneao

Cause:

• A dither script has been introduced (May 2021) to enable limited (2-arcsec) dithering in LGS mode, even in the absence of Tip-Tilt motors:

  user@shimmy:∼/observers/lgs/scripts/lgs-ttroi.tcl

  Some keywords relating to the coordinates of the (region of interest, ROI) in TTPeeko were introduced. The normal coordinates of the centre of ROI prevailing during May 2021 ShaneAO were: (48,39).

  However, it seems that the newly-introduced ROI keywords/modifications sometime yields unintended consequences.

Associated:

• Peeko/TTPeeko
• Report of the present ROI (i.e. box centre, size): >>> tt_roi()
• To re-size ROI, use the following convention: >>> tt_roi([xcen,ycen],[xdimension,ydimension])

  For example: >>> tt_roi([48,39],[10,10])

  A limitation demands that even numbers MUST be used for box dimensions.

Change Log:

2021-05-30: First version.