Astro-Physics AP1100 APCC Pier Flip Failure

Sequence Generator SGPro Support
1

Description

Generally pier flips have been working with SGP 4.0.0.680 and APCC on my AP1100, however last night it failed an unattended pier flip and aborted my sequence for the night. So I lost about 5 hours of imaging.

It has been working, but I was always worried that I might run into the same issue as I have when I do a delayed counter weight up pier flip. When using APCC and using the delayed counter weight up functionality, everything works fine with SGP until the actual flip is commanded. When my AP1100 mount slews from a counter weight up position it performs a “Safety Slew”. First the mount only moves in RA to get to a counter weight up position as this prevents the dec from rotating the scope into pier. The mount pauses for a couple of seconds after the RA has moved to counter weight level before it starts the move the requested RA/DEC or pier flip.

This is when I think the problem occurs. SGP thinks that the mount has already completed the slew and gives the error that the scope is still on the West side of the pier due to this delay. I currently have the pier flip delay set to 1 min past the meridian to prevent the scope from oscillating back and forth during the plate solve after the pier flip, but it looks like this time the safety slew delay caused SGP to abort. It would be really good to get this fixed as then I could use the delayed flip feature of APCC and SGP, but at the very least, this needs to be made reliable with a standard flip.

I have included both log files, and will also post it on AP’s forum. But I don’t want to get caught between two companies blaming each other. SGP and AP are both premier companies in my mind and I just want to get this working.

Link to Logs

https://drive.google.com/drive/folders/1OIw_Wl-woeZOhckmpu6_BLrnRSlvSoQv?usp=sharing

Useful Info

OS: Windows 10
Ver: SGP 4.0.0.680 64-bit
APCC Version 1.9.0.7

2

I put the same post on Astro Physics web site, and I think that I now understand what happened. When SGP reached my meridian flip offset of 1 minute, it commanded a pier flip slew. However, because there was a target offset created from the plate solve in SGP coupled with the error in the pointing model in APCC, the mount saw a slew command that was still west side of the pier. So, the mount did not pier flip and SGP saw that error and aborted. I need to figure out the best way to make sure that when SGP commands pier flip coordinates they are close enough to the mount model to prevent this failure in the future.

Perhaps I need to use Sync under Telescope Sync behavior instead of Target Offset?

3

I just want to reinforce that this was not an issue with either SGP or the APCC programs. Rather, a settings issue that I had. I will use Sync from now on to ensure that the mount and SGP are both operating with the exact same RA/Dec from the plate solves. That way I shouldn’t have issues with RA being so far off on a Pier flip to cause the mount to stay on the West side of the pier.