SharpCap Forums

I could use some help understanding this behavior of the sequencer. When I try to do a sequence step that moves the mount (it is an equatorial mount) to an Alt/Az coordinate, I incur an error indicating that the tracking on the mount must be off. If I turn the mount tracking off and then execute the move mount to Alt-Az, it works fine; this seems to support that the mount is capable of accepting Alt/Az gotos.

I scanned the Sharpcap documentation and the sequencer commands and there does not seem to be a command to turn on/off tracking?? This is certainly not a big deal and I think I may be able to work around it by writing and calling a special program that communicates directly with the mount.

Why would I ever consider using Alt/Az gotos on an equatorial mount, one may ask. I am working on a automated alignment script and it occurred to me that the usual approach would be to align to a star, sync the mount and then move on to the next alignment star, repeat until the alignment is complete.

However, with plate solving, there is nothing sacrosanct about doing a goto to star location. Given that is the case, it would seem to make sense to goto a number of locations based on Alt-az coordinates, rather than star locations and do plate solving and syncing at those locations. If this worked, it would eliminate the need to pick the stars for each alignment session.

Hi,

what you are encountering is a 'feature' of the ASCOM driver you are using - some drivers will happily slew to AltAz co-ordinates when tracking, others won't (there is nothing in the ASCOM standard documentation that defines whether it is legitimate - at least nothing I can see). That essentially explains why this isn't something I can document in the manual, since the info would vary from mount to mount.

In general, there's not really much of a reason to use the slew to AltAz co-ordinates, but it was easy to add to the sequencer, and someone will no doubt find a use for it.

You can turn tracking on or off using the sequencer with the 'Set mount tracking rate to ...' command - one of the options is to set 'None' as the tracking rate.

cheers,

Robin

Robin,

Thanks again for your help. I didn't see that set tracking rate could be set to none. Off to experiment.

Just tried setting the tracking rate name to "none" and then commanded the Alt/Az move and it it worked a treat. Thanks again!