Usability enhancements: PHD2 and SGP synchronization and resumes


Over the last few years, there are instances when SGP and PHD2 get out of sync. At all times, if I start a sequence via SGP and allow it to boot up PHD2, connect, calibrate and guide, all goes well. The niggles occur when you pause or abort and try and restart. Sometimes PHD2 does not start guiding, or the opposite, it may be guiding, yet SGP sits and waits for the guider to start up or settle - clearly it is out of sync somehow.

It is also sometimes the case that at the start of a new sequence, even before the first exposure is made, it is necessary to abort, make some changes to the control panel etc and restart. In these cases, not only does the abort move the sequence to resume status, when you hit resume, the missing elements of the sequence start up are skipped over and it is necessary to do a full abort, sequence reset and start over.

These general observations highlight some practical suggestions:

1 Can SGP and PHD2 communicate in such a way with regard to status, so that SGP does not have to assume a status, which, if it has been interrupted, could be out of date?
2 Can an abort, made before the first exposure completion, reset the clock so to speak, so the the sequence action button returns to ‘run sequence’ rather than ‘resume sequence’


I think that as far as number 2 goes, if you actually have no progress on the sequence, then yes, you can “reset” sequence progress and it will change to “start sequence.” Not sure how this would work, though, from night to night on the same sequence.

Best regards,


Craig - not quite - since the connections to PHD2 can be in a state of flux and to be sure that PHD2 synchronization is guaranteed, you also need to disconnect PHD2 and close it. It can be done, just a bit cumbersome.



Bumping post - one year on. Ken, please can you take a look and see if you can improve the robustness around PHD2 interaction with SGP. The problems I mentioned last year remain. SGP and PHD2 are just fine if you let SGP start up the sequence, I run into problems when I have to abort and restart a sequence. A pause / resume is normally fine, but if I abort and restart - that is when the problems set in. PHD will either not reconnect to the equipment (if I have done a disconnect all in SGP) or not start guiding and SGP hangs a little later on. I have even closed PHD2 on some occasions and it will fire up again but not connect. I can provide log files but it is completely repeatable and I’m sure I am not alone (I suspect some other posts with regard to PHD2/SGP interaction may well be the same issue) . I’ll put together a list of known command sequences that end in a problem. I don’t know whether it is PHD2 not updating some form of broadcast status, or SGP not enquiring and/or assuming a prior status.