Rotator throwing exception


#1

I’m running an Optec Gemini rotator, which is randomly failing to complete a rotation command. This typically only happens when moving the rotator as part of a meridian flip or when SGP is moving to a 2nd or 3rd target of the evening. However, last night it happened on the initial target start.

SGPro ver 3.0.2.91

Exception text:

[08/08/18 21:46:02.983][DEBUG] [PHD2 Listener Thread] PHD2 GetPhdStatus - Post-Wait: Stopped
[08/08/18 21:46:23.070][DEBUG] [Telescope Thread] ASCOM Rotator: Error in Move(abs) : CheckDotNetExceptions ASCOM.OptecGemini.Rotator
IsMoving Get System.NullReferenceException: Object reference not set to an instance of an object.
(See Inner Exception for details) (System.NullReferenceException: Object reference not set to an instance of an object.)
at ASCOM.DriverAccess.MemberFactory.CheckDotNetExceptions(String memberName, Exception e) in
c:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 630
at ASCOM.DriverAccess.MemberFactory.GetTargetInvocationExceptionHandler(String memberName, Exception e) in
c:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 664
at ASCOM.DriverAccess.MemberFactory.CallMember(Int32 memberCode, String memberName, Type[] parameterTypes, Object[] parms) in
c:\ASCOM Build\Export\ASCOM.DriverAccess\MemberFactory.cs:line 288
at ASCOM.DriverAccess.Rotator.get_IsMoving() in c:\ASCOM Build\Export\ASCOM.DriverAccess\Rotator.cs:line 83
at SequenceGenerator.AscomRotator.g5(Single A_0)
[08/08/18 21:46:23.071][DEBUG] [Telescope Thread] Rotate failed…

Full file (Dropbox):

SGPro log

Charlie


#2

That looks like the rotator disconnected. Maybe a cable getting pulled tight?

Thanks,
Jared


#3

@Jared

I have through the mount cabling that is well managed. The Optec focuser has locking cables, so they can not be jiggled loose. My experience has been that the NullReferenceException is usually thrown when there is an invalid pointer to the object.

My recovery has been to simply terminate SGP and then restart everything. This has always cleared the problem.

Charlie


www.mainsequencesoftware.com