SGPro Fails to Center On and Slew To at Sequence Start


My target is NGC7023, in the general neighborhood of the star Deneb.
I’ve been running this same setup, target and Sequence for a few nights. Last night was the first time SGPro did this.
I had opened the OBS around 4:30pm. I opened SGPro and connected camera, scope and dome. Then used the hand controller on the scope (Meade 12"LX200 Classic) to slew to Deneb. Everything was left on and running.
A few minutes before 6:00pm I manually centered Deneb, sync’d, and manually focused with a B-mask. Nothing new about this approach.

I started the Sequence at 6:00:08.
Scope reported at 6:00:14 that it was slewing to the target. However, nothing moved, scope remained on Deneb.
Plate Solve2 began and reported at 6:01:05 that the scope was pointed at Deneb’s RA and Dec.
Scope and Dome began slewing to NGC7023’s RA and Dec at 6:01:15.
Everything aligned and all worked well from thereon.

I’ll be doing the same target again tonight and will report on whether it fails to initially Center and Slew.



Not sure here, I’ll need to look deeper…

[12/6/2015 6:00:14 PM] [DEBUG] [Sequence Thread] Telescope: Slewing to J2000 RA: 21.0019444444444 Dec: 68.1636111111111
[12/6/2015 6:00:14 PM] [DEBUG] [Sequence Thread] Telescope: Slew received J2000 coordinates, mount requires JNOW, converting…
[12/6/2015 6:00:14 PM] [DEBUG] [Sequence Thread] Telescope: Slewing to JNOW RA: 20.6991666666667 Dec: 45.3297222222222
[12/6/2015 6:00:14 PM] [DEBUG] [Sequence Thread] Telescope: Slewing to RA: 20.6991666666667 Dec: 45.3297222222222

It starts with the right DEC, but I guarantee that the JNOW equivalent of 68.16 is not 45.33


This is what I think was happening:

Dec 68.xx is the target value (NGC7023). And this is where SGPro was reporting that the scope and dome were heading - even though they weren’t.

Dec 45.xx is where PS2 was reporting the first plate solve was taken. This was Deneb, even though the scope was reported to have moved to NGC7023.

PS2 saved the day and had SGPro move the scope (finally) to its destination.

I ran the same routine this evening. This time everything worked well. Manually aligned, sync’d and focused with Deneb. The start of Sequence sent the scope to NGC7023. PS2 did its finishing work and all is well.

Likely just a one-off.



Maybe… I still don’t like the fact that I cannot figure out how the entire requested location seems to have been swapped out from under the slew process after the epoch conversion took place. I am not sure how this could happen and I’m very curious if you are able to reproduce. It can’t be data from a PS2 solve… from the logs, it looks like the first PS2 solve takes place after the slew. The swapped coordinates are seemingly directly from the scope itself (where it thinks it is pointing) and thus the reason no movement is observed… I just have no idea how a conversion of Epoch suddenly swaps the scope’s current position into the desired “slew to” location.