SharpCap Forums

After successful plate solving I receive this error message:


The Dutch part of the error message: <the object reference is not set to an instance of an object>

The mount will move a bit but afterwards the alignment is totally lost.

With my Celestron Nexstar Evolution 8 mount no sync error is generated.

Attached is the log file retrieved just after this event.

SharpCap V.4.0.8282
Windows 10
ASCOM Platform V.65-SP1
Planetarium program: CPWI or Stellarium (same error with both, so probably ASCOM error).

Hi,

I think there might be a bug in the way that SharpCap is talking to the mount here - I will try to add a fix for the next update, but I'm not sure if it will work correctly or not.

The SE mounts are a bit odd - although they are AltAz, from the ASCOM point of view they work more like an equatorial mount - for instance the mount claims it cannot sync to AltAz co-ordinates. In the current version, SharpCap tries anyway (some mounts lie about their capabilities and say they cannot do things that they actually happily will do). After the sync to AltAz fails, SharpCap tries an RA/Dec sync, which then also creates an error from the ASCOM driver. What I don't know is if the second failure from the ASCOM driver is caused by the first incorrect attempt to sync to the AltAz co-ordinates or not - I will change around the code and we will find out

cheers,

Robin

Hello Robin.

Do you already had time to correct this issue?
This evening I probably have the occasion to test it with the 6 SE.
Thanks in advance.

Hi Roel,

yes, I did change the code so that the RA/Dec sync will get tried first - that should be in version 4.0.8315 and newer versions. Worth a try to see if it helps.

cheers,

Robin

I had the opportunity to test it tonight.
The following error is displayed:
<Could not sync mount to plate solve location. Method SyncToAltAz is not implemented in this driver.>
I have also included the log file.

Hi,

thanks for the log. This time SharpCap tried the RA/Dec sync first, which failed with an internal error inside the ASCOM driver Then SharpCap tried the AltAz sync as a backup, and that failed too.

Let me spend some more time on this - I have an SE8 mount here that I don't use often, but I can try to see if I can make the same problem happen.

cheers,

Robin

Ok,

so I can't test the setup you are using with CPWI because my hand controller is too old to be compatible with CPWI - I have to use the 'Celestron Telescope Driver' ASCOM driver, which works with my SE8/hand controller and has no problems with sync. Does that ASCOM driver option work with your newer hand controller?

cheers,

Robin

Yes that driver will work. I tested this (without CPWI) earlier with same sync problem.
But not tested it again after you changed the code.
So I will try again if weather permits.
For me the advantage using CPWI is that I can do a StarSense user auto align from inside the house (mini PC at scope).

Another consideration: I think when you update the firmware of your HC to the recent one CPWI will work.
Would it be possible to test that?

And known I see you used a standard Nexstar+ HC, where I use a StarSense HC.
That could also be a difference.
But CPWI doesn't run via the HC so I'm a little bit confused now.

Hello Robin.
Because of the bad weather forecasts I want to test the plate solve syncing inside the house.
Is their a way to test this without going outside? If yes, how do I perform this?
Thanks in advance.

Hi Roel,

you can test indoors by using 'Test Camera 1 (Deep Sky)'. Let it load the default M42 image, then connect the mount and manually move it to point somewhere fairly close to M42 in RA/Dec co-ordinates. Then run the plate solving, which should move the mount based on how far your 'somewhere close to M42' position was from the image position. Obviously the image won't change. If M42 is below the horizon then pick another image of a different target and apply the same steps.

I don't think my handset is upgradable to the firmware that supports CPWI, since it is an older Nexstar (non+) handset from about 2008 or so.

cheers,

Robin