SGP and PHD2; How to Start



When assigning PHD2 as the guider to the sequence, should the guider be running already or should it be left to SGP to launch and run the guider? I have tried both ways tonight and the “starting guider” message is perpetual. I have disabled guiding in SGP and am ot dithering just so that I can keep the sequence running with guiding going separately. I would like to know the proper way.




Things to double check:

  • “Enable Server” is checked in the PHD2–>Tools menus
  • You have the right profile configured for PHD2 in the SGP guider settings (i.e. the same equipment profile you would select in PHD2 when conencting your equipment)
  • Your guide settings in SGP are correctly set in the COntrol panel (and not just in the Equipment Profile view)

Other than that, you could upload your SGP logs here so we can see what’s going wrong.


Steve, thanks.

Assuming all is well, what is the process:

[1] Let SGP launch PHD2, get it to connect to its equipment, get it to loop, get it to begin guiding (calibrating if needed)?

[2] Have PHD2 ready to loop, then start SGP and let it command PHD2 with loop and guiding/calibrating?

[3] Have PHD2 guiding then start SGP?

What does SGP expect?




I use option #1 - I just let SGP open, start, connect, loop and guide PHD2.

And yes, if there is no calibration, PHD2 will automatically do one when SGP tells it to start guiding. Alternatively, you can configure SGP to tell PHD2 to re-do calibration every time you move to a new target (this is needed if your connecting to PHD2 via ST4 instead of ASCOM)


So you don’t know what SGP expects and prefers to do, but you know that with letting SGP take control from beginning you have had success.



And as I’ve posted on other threads, I had issues why trying to pre-start PHD2 to different states. Now, I get consistent success by just not starting PHD2 at all, and letting SGP fully control it.

Others may have a different story :slight_smile:


That is good to know. I hope SGP will also chime in and let us know what the design is and what is recommended. It looks like there may be an issue in my setup, and I will share the log this afternoon. And if there are flexibility in operation I would like to know about them.



…testing again tonight I discovered that SGP wants PHD2 be running and equipment being connected, ready for calibration in order for SGP to successfully launch PHD2. And there is a problem that the notification on the bottom left of the screen is somewhat deceiving: even though it may have made contact and has initiated calibration process it still says “trying to connect to guider” or something like that.



So you were able to get it working? :slight_smile:

And just to clarify terminology: In this case you had already pre-launched PHD2 and connected it to your equipment (but I assume had not started looping yet?).

When you say “for SGP to successfully launch PHD2” I think you mean “for SGP to successfully connect to PHD2”, as it has already been launched/opened.

I don’t actually think SGP “wants” a specific start procedure: When it tries to connect to PHD2, it will first check if PHD2 is already running, and launch it if if is not. If PHD2 is already running, SGP will just try connect to it, so either scenario (PHD2 running or not running) should work.

Anyway, if you now have a start procedure that works for you, stick with it!


I tested it at various stages. While PHD2 was not launched (not running), SGP was perpetually trying to start it. When PHD2 was active but no equipment connected yet, SGP was perpetually trying to start it. When the equipment was connected in PHD2, then SGP took control, began looping and initiated calibration. However, its message still was that it was perpetually trying to start PHD2.

It would be nice for a developer to chime in and let us know what the intent is any way although I now have a workflow.



I would like to know why SGP does not only disconnect camera and mount, but why does it not shut down PHD2? It effectively shuts down my EQMOD and my focuser, camera and filter wheel.


Hey NovaTJ,

Might be better to start a new thread on that question.

As I understand it, SGP does stop guiding and disconnect from PHD2 when a sequence ends, so not sure that leaving the PHD2 app open would cause any problems.



No, I don’t have a problem with it staying open, just wondering why SGP does such a good job closing the other pieces of hardware and software, but not PHD2?


Fair enough.

There does appear to be a shutdown command that SGP could send to PHD2 (…maybe it will be added at some point :slight_smile:


I never had a problem connecting to PHD2, no matter what I did it connected and started guiding and sequencing. Whether I started it manually or let SGP start it, it didn’t matter, until I changed guiding cameras. I setup a new profile for the new camera, ASI 290mm. Now can’t get it to work. It will start PHD2 and go through the whole setup, but hangs up waiting for PHD2 to start guiding when it is already guiding. Also, SGP usually picks out terrible stars to guide on. What I have been doing is using SGP to plate solve, then using SharpCap to capture my lights. Problem with that is I can’t dither…


One problem that I see is that it takes SGP a long time to stop trying to start something it has already started, and then to move on. Occasionally I just tell it to stop and I reconfigure it to not know there is a guider.