Disturbing Entry into the …402 release notes

I was going to setup the new SGP version on my “production” computer when a line in the release notes caught my eye. It reads:

I am running a remote roll off shed and the telescope must be at park before the roof can be closed. Will now SGP not check anymore if the scope is at park before closing the roof? Is there some timeout so that the roof will be closed no matter what?

I can imagine the roof cutting short the top 30% of the scope and I hope this is not true …

Kind regards,

This was done in response to the discussion at Beta Parking scope in Infinite loop I believe.

You make an excellent point : It does not seem clear from that description whether or not SGP will honor the “Park Mount First” checkbox now in Observatory settings. It SEEMS like it’ll tell the telescope to park, but not wait to see if it actually is before doing other thing…including telling the roof to close.

Good catch…be interested to hear the response.

The sequence might end, but the mount controls the order of execution (not the sequence). This will not be affected.

Perhaps I’m being dense here (highly likely) but I don’t really understand your statement, Ken :

The sequence might end, but the mount controls the order of execution (not the sequence).

How is the mount controlling anything?

If I followed the other thread, what happens now is that SGP tells the mount to park, but then does not wait for ASCOM to return before moving on to the next step…which might well be to tell the roof to close.

If that’s the case, then even if everything functions normally, simple timing (mount slews slowly, roof moves quickly) could create a crash.


Not really sure how to explain this… SGPro is a multithreaded application. The sequence itself runs on one thread and telescope actions happen on a different one and observatory actions happen on their own thread. All of these threads are independent of one another and they are all running at the same time. If the sequence tells the mount to park and then does not wait… who cares? The sequence is not controlling when the observatory shutter closes. The sequence thread asks the telescope thread to park and then moves on and does dumb sequence things. The telescope thread is now in charge and controls when the dome shutter is closed. It is slaved to the telescope and will not shut until the conditions you specified are met.

That was the part I wasn’t getting. :slight_smile: I knew SGP dispatched various threads to do things, but I thought they were two different threads, and essentially SGP would say “Hey mount, park” in one thread, and then “Hey roof, close” was one of those “dumb sequence things” it might do in yet another thread, without consulting the mount.

Makes sense now. Much obliged to you for dumbing it down for me. :slight_smile: