Greetings,

having upgraded to ACP8 from ACP6, the very first image of the night of course yields a SyncToCoordinates from ACP as I still have few correction points in ACP's pointing corrector. But the odd thing is that most often after ACP receives the pointing error from Maxim, instead of slewing to the original intended target, it slews to the very same coordinates the scope has been told to sync to, thus the scope moves not at all, and the image is of course still off from the original one. Then ACP slews to the original intended target. Odd because this only seems to occur perhaps 80% of the time (beyond maximum error?). More problematic is that the offset occurs night after night, of the same magnitude (0.3 deg in RA). I had no such issue with ACP6.

My setup is a DIY, the Dec and RA axis are 17 bit absolute encoder, so the HA and Dec of course never drift. I am using current sidereal correction which yield topocentric scope coordinates. I ask because the 0.3 deg is just about the time between the image was taken and the sync is issued. I would have thought that absolute encoder require no Sync as ACP keeps track of all correction throughout the sky and should remain static throughout time (barring frost upheavals, etc).

Where may lie the problem?

Cheers