I have searched the Forum for Solver and Sync issues and have seen that others have similar issues as I do, but I have not found a definitive solution. If I have overlooked it, perhaps someone can point me towards it.
The problem is this: Tis the time for the annual Messier Marathon, so I thought I could set up a schedule in Ekos and see how quickly I can image all Messier objects at 60s exposure per object, followed by slewing, solving, guiding and imaging of the next one, and so on. A nice endurance test for Ekos.
Unfortunately, I did not get very far. After several restarts two different things had happened: 1) The mount rapidly loses synchronization, i.e. after plate solving the mount would always be a variable distance (up to a degree or more) off target. The displacement would be detected correctly and displayed also in KStars, but the mount would never slew to the correct position. It would indicate that it was slewing, but the next plate solve would again be very close to the previous - wrong - position. I.e. Ekos detects that it is in the wrong position, sees the correct one, but then slews back to the wrong position. After doing this several times, the scheduler gives up and goes to the next target. Which then also will not be found, this time the displacement is greater than before. After a few iterations the telescope points to random coordinates in the sky.
2) The second problem is different. In that case, Ekos solves the position of the target, but it is several arcmin off target, yet states that the target is within acceptable range (less than 1 arcmin, in this case). Since the target is not centered, I try then to run the solver again, which very quickly tells me that the target is within acceptable range, but now it is off by several arcmin more. Repeat that a few times and the target will have drifted off the frame completely while the solver still tells me that it is within acceptable range.

Has anyone seen a similar behavior? I am using EQMod on an Orion Atlas Pro AZ/EQ-G (set to EQ, mode, of course).

Jo

Do you have previous sync points saved up? Try to clear them all before you start your session. In the mount tab, you can clear the alignment model. There is also option in the scheduler settings (Settings --> Ekos --> Scheduler): Reset Mount Model after Alignment Failure. Make sure this is checked. I might also add another option to reset mount model when starting a new job to make sure we're in a 'clean state'.

That seems to have corrected the problem for the most part. I will do a "stress-test" running the scheduler through 30+ different objects using single short exposures with the full range of tracking, focusing, guiding and capturing to see how it behaves under the most adverse circumstances.
Thanks!
Jo