Re: Heads-up on possible abrupt parking problem #APCC #Absolute_Encoders #Mach2GTO


Howard Hedlund
 

Dave's theory was a good theory, but I'm afraid it wasn't correct.   Here was my response to him sent well after his post, so I repeat:  At the time it was a god theory.   The short-term quick-fix is to simply set the park timer to a larger value.  I suggested 5 minutes.  
Response:

I still think something is causing a restart or an extended timeout of your computer.  Have automatic Windows updates been either turned off or else set to a time when you are not imaging?

  • The timekeeper for the park timer is in the GTOCP5 control box, not the computer or APCC.  APCC simply tells the park timer to start its specified countdown.  After that, the mount counts down its time like an egg timer.  If the timer goes off, the mount parks.  It is APCC’s job to keep resetting the timer before it goes off.  The default timer is set for 1 minute, but APCC generally resets it every 8 or 9 seconds, so the countdown never even gets close to going off.
  • The MGBox ‘s GPS times are consistently off by a couple seconds compared to the PC time throughout the log.  Polling occurs every second.  I never found a discrepancy anywhere close to 2 minutes 48 seconds.
  • After initially setting the time in the GTOCP5, there were no corrections to the mount time sent until AFTER the event, and that was a 1 second correction.  If the PC had corrected its time, an equivalent change would have been sent to the mount within a few seconds.  There was no correction sent to the mount. 
  • Computer time was about 2.9 seconds ahead of the MGBox’s GPS time before the glitch (fancy technical term).  It was about 3.4 seconds ahead after the glitch.  That certainly wasn’t a correction to the time.
I am not an expert using Windows Event Viewer, but I would like to see whether it confirms my suspicions.
HH

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