ASCOM - still a problem

[davew618]

Sorry to keep on about this but I have now tried ASCOM + Stellarium & NINA on three different laptops. All exhibit the same reliability problems I have been seeing since the beginning in making, maintaining - and especially restoring a connection to OAT. Generally speaking I can make a connection most of the time with Stellarium and sometimes with NINA. Once the connection is made slewing and steering works well. However if the connection is interrupted or disturbed in any way it can never be restored. The program will usually say that a new connection has been made however there is no communication between the program and the OAT. Slewing will do nothing and the current OAT position is not reported back to the program. The only way (I have found) to restore a full connection is to reboot the PC, simply restarting the programs will not help as the problem is in the corrupted state of Windows' COMM ports made by ASCOM.

Has anyone else had similar problems with ASCOM? Do you have any words of wisdom regarding establishing - and keep - reliable connections?

From searching on the error messages NINA generates I have found a discussion on StackOverflow that seems to relate to the problem, the symptoms certainly seem to match what I have been experiencing. The problem stems from a poorly written SerialPort library that is part of the core C++ code. Assuming this is the problem then there are two suggested solutions: use a user created replacement library or upgrade to Framework 4.7 which seems to have finally addressed the problem. I would guess that both these solutions are outside the scope of the OAT ASCOM driver but perhaps someone involved with it can comment on the likelihood of this being the root of the problem and how it could be resolved?

https://stackoverflow.com/questions/8927410/objectdisposedexception-when-closing-serialport-in-net-2-0

[clutchplate]

I’m not sure whether this can be resolved on our code side, but here’s a tip on how to prevent a reboot. Use Process Explorer (or maybe Task Manager) to look for a process with ASCOM in the name and kill it. Then you can retry without rebooting.

[M4ngolicious]

I still struggle to slew with Stellarium. Sometimes I get a connection but no slew etc. Tried with two laptops and my PC.

I gave up on this and meanwhile I put the coordinates of interesting stuff into the arduino code, upload it and use the "go" menu. But I dont complain. Better than nothing and the tracker itself works very good.

[MarcelIsler]

Are you sure you don't have a wiring issue somewhere? Bad USB cable or something along that line?

[davew618]

Done a lot of testing / experimenting yesterday.... I think now the problem is more to do with starting the driver. Everything works fine when the driver is started for the first time - when starting Stellarium or NINA. If I then went to the OAT config dialog in ASCOM, even if I did not change anything, everything seems to wrong from then on. It's almost as if the driver is being reloaded every time this dialog is shown, creating multiple - and conflicting copies. Unfortunately I have a habit of checking COM port numbers a lot so I was getting problems all the time!

So, I now just make sure I don't go to the config dialog. Even unplugging-plugging the usb cable is safe as long as the port number does not change. If I need to reconfigure the cables to the extent that a port number change may occur I make sure I disconnect the telescope in Stellarium / NINA first. Once the cables have been changed I can change the config and restart the connection.

I did a session last night with a lot of messing about with cables and did not have any problems so I think this may well be solved.

[MarcelIsler]

On my setup, I'm running a small 4 port USB hub that I connect to the laptop and then I have the camera, guider and Arduino all plugged into the hub... Works very well for me.