Failure after Meridian Flip

Things have been running smoothly for many sessions…until last night. Set up an RGB sequence to be followed by darks and biases. Everything was working great and I was sleeping. This morning I woke at 5 and saw the darks being captured, but the sequence had not finished the green filter and skipped the blue filter entirely. The last image was taken at 2:50 am (a green image). It appears that after that last green image the mount then meridian flipped and then problems started. It never took another light image for the next 90 minutes or so, and then started the darks. The mount was parked successfully and the flip flat closed, so SGP was mostly running well. There could have been an issue with PhD, but I closed that before I saw what was going on.
Here is a link to the log file. If you need the PhD log I can post that later.

I see where it changed the filter to position 3 around 2:50 am and then went through it’s process to settle the mount and performed an auto focus and then begin guiding.
At 2:52:32 it reported an unknown object in PHD. It then spent the next minute or so going through the process of settling the mount and completed that, only to come back and report that the next image could not be completed in enough time prior to the meridian flip. So it aborted it.

It looks as if at that point it moved on to the calibration frames and started capturing those.

There are people here much better than I to look at all of this, but that is what I’m seeing.



So, there are two things going on here…

1.) Your platesolve2 solves started failing. We see it every now and then and we have never fully been able to understand why. We see messages like this in the logs:

APM file found, but could not not be opened.

We know this means that PlateSolve2 froze and did not release the solve file so SGPro could open it. Unfortunately, we are not 100% certain why PlateSolve2 freezes, just that once it starts doing this, it won’t stop. The leading theory on this is that the “PlateSolve2.ini” has become corrupted. I would start by deleting this file (SGPro -> Help -> Open Log Folder) and then going through the PlateSolve2 setup again:

Because of this issue, SGPro kicked it over to Astrometry.NET for blind solve and the good news is that the blind solves were just fine. The bad news is that due to a bug, we counted the solve as no good and aborted the sequence. This has been fixed in betas of SGPro > (not released yet)

Hey Ken,

Is there a manual or something to help me learn how to read the logs? I would really love being able to spot things like this and be able to help myself and my friends? And who knows, if I get proficient enough at it I could help people that post issues.

It’s fun to be able to help people sort through a problem and then get things up an running.



There isn’t. The logs are difficult to read and require a fairly deep knowledge of the software’s code to interpret. Often they are not use in and of themselves and don’t become useful until cross-referenced with the source code. The best course of action to help others is to use a snippet of the logs that seems like it’s a problem and search the forum. This is why we discourage support by email… in order to build up this knowledge base. As a final thought, we do offer a version of logs that are intended to be more user friendly. These can be accessed via the notification system (Text File endpoint). They won’t give details, but are often pretty good at showing what and when something went wrong.

I did as you suggested and SGP ran fine last night until the meridian flip. It had no problems doing plate solves and there were no other hints of problems. The failure happened pretty late at night, I did not wake up in time, it had already mis behaved by the time I got to my laptop. I stopped everything, re-started SGP and was able to continue taking images (including plates solves) just fine.
Here is my log file:

Note that the last two nights are the first time I have seen any issue. I have had no problems like this for the last two years.

Just to be clear. The mount did do a meridian flip and ended up pointing where it should, it was only about 40 arc seconds from being pointed where it was before the flip.


Same issue happened again: PlateSolve: APM file found, but could not not be opened.. I don’t know if we will ever be able to determine what corrupts the PlateSolve2.ini file, but I have an idea that may help to stabilize and ease setup for PlateSolve2

Yeah, this is similar to the problem I had and reported a few days ago - the second plate solve starting while the first one was still running - same error message.