SGPro not controlling PHD2 properly

My usual telescope is a William Optics GT81, which I use with a ZWO ASI120mc guide camera and a separate guide scope. For galaxy season, I am now using a Meade LX200 SCT with a ZWO 174mm as the guide camera on an off axis guider.

Gear other than that is the same ZWO ASI183mm mono cooled camera, ZWO EFW filter wheel, Losmandy GM8 mount.

I have controlled the the GT81 setup with SGPro and the GT81 for a couple of years now, and had no issues, SGPro controls PHD2 properly, starting and stopping the guiding process correctly.

It’s taken me a while to get used to the LX200, and originally I controlled it with APT (Astro Photography Tool). But have now migrated to SGPro. I have separate PHD2 profiles for the two telescopes, and separate SGP equipment profiles, the guiding part of which calls up the relevant PHD2 profile.

If I start PHD2 stand alone, with the LX200 profile , the guiding works fine. But if start the SGP sequence (with the right SGP Profile), it slews to near the target correctly, plate solves for the auto centre process, then says “Starting Auto Guider”… but it never does, and the sequence doesn’t start. It does the same whether the guiding has been already been started independantly or not. If PHD is alread stared I can see that it is actually guiding correctly, so it’s not an issue that it can’t find a star or anything like that.

It seems purely to be an issue of the two programs not communicating.

I haven’t yet reverted to trying the GT81 setup, I’ll try that next time out.

Has anyone any suggestions as to how to diagnose, or fix the problem…



I run into problems if I mess with PHD2 while trying to use SGP. What works for me is to independently calibrate PHD2 at low DEC and then save the calibration and shut down PHD2. I do this just once while my rig is assembled or not altered.
In SGP, let it fire up PHD2, connect the camera and mount and let SGP entirely run it. For many years, if you go independently into PHD2 and pause/stop/start it, it sometimes loses sync between SGP and PHD2 and the two wait patiently for Xmas.

Thanks Buzz. Sounds like good sense.

I have a slight issue there. I have two ZWO cameras, the only way I can get the correct allocation of those cameras is to disconnect my main camera, and then start PHD2 and connect to the guide camera.

Then plug in my main cam and connect to SGP. Both cameras are then allocated to the correct program.

So I can’t let SGP actually boot up PHD, it needs to be already connected. But what I can do is to make sure PHD, although connected, is not actually running and see if SGP actually kicks it into life.

I sometimes have the same issue with my two QHY cameras. The QHY cameras have several ASCOM ‘devices’. Imaging and guide camera 1 and 2. Once I set the imaging and guide camera, it remembers that in the ASCOM driver for next time I power up. Does the ZWO behave similarly?

You’d think we’d learn would you, I now have 3 ZWO cameras, and no others!.

About a year ago, I did try asssigning the cameras to ascom camera 1 and ascom camera 2. The programs correctly picked the right cameras, so I could leave both leads connected. I’m pretty sure though that I lost some functionality … I couldn’t set parameters (gain maybe?).
Perhaps worth me trying this again, I know the drivers have been udpated…

More information…
1)It seemes to be only with this set of gear, the GT81 stuff still works.
2)If I start with PHD2 running, but not looping, I can see that SGP starts PHD, chooses a star, asnd starts guiding… It then just sits there saying… "Starting the auto guider-please wait… forever… BUT…
If I stop PHD guiding, SGP recognises the fact, and end the sequence…
So, it isn’t talking, but it is really!