Re: APCC/Driver exception

Ray Gralak

01:59:08 Illegal operation while parked
I think this says it all! The mount needs to be unparked before attempting a slew.


-----Original Message-----
From: [] On Behalf Of david w pearson via
Sent: Wednesday, November 3, 2021 4:52 PM
Subject: [ap-gto] APCC/Driver exception

Hi Ray,

I am getting this error from ASCOM/driver

"check_connected: Exception : bMustNotBeParked and g_bParked: True, True : SlewToCoordinatesAsyn"

Do you have any insight on this exception and what may cause it?

I use CCDCommander for my auto imaging script.
After parking the mount due to bad weather/Roof Closure, and being in a weather pause for maybe hours, i
get this error after coming out of a weather pause and restarting my imaging session.

CCDCommander log
01:59:08 JNow Coordinates: RA: 05h 29m 45.0s Dec: +34°26'29"
01:59:08 Slewing to Sh2-234...
01:59:08 Error Number: -2147220471
01:59:08 Illegal operation while parked

I have enclosed a summary txt file of CCDCommander and APCC(to shorter the search)

In summary....CCDCommander goes into weather pause, and tells APCC/driver to park and it does.
After the weather pause, CCDCommander tells APCC/driver to go to last image and it appears to do
that.....however, "at park" stays true.

question here.....when "at park" is true, does this just mean not slewing or tracking? Slewing and tracking
stays false.

CCDCommander discovers that the last object is not the planned object due to the weather delay, and tells
APCC/driver to slew to correct object, and the Exception occurs.

Mount is parked at alt/az of the last object when exception occurred and of course is still there upon
observing the mount next morning.

I realize my issue is an interface issue between the mount and CCDCommander, but maybe if there some
possible issues
that make this happen i can work around it or get Matt at CCDCommander to fix.

This has been a CCDCommander issue since i started in 2010 and has been noted by others over the years.
I have talked to Matt about it and he has given me workarounds to try, but none have worked.

So i decided to try to figure it out myself, and pass info over to Matt.

Any ideas what is causing the APCC exception?

I know this is not really your issue.....but a lot of us have been struggling with this for some are
probably our last hope.(pun intended!)
Thanks... if you choose to accept this challenge!! Hopefully easy for you!


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