Setting up Pulse Guiding with EQMOD

[RowlandA]

Hi Hamza,

I am evaluating Prism Advanced and have enough working to do an automated unguided run all night. I'm impressed with the depth of this software!

I have not yet been able to get Prism guiding to calibrate using EQMOD and a SIrius EQ mount. I can calibrate with PHD2 so I'm pretty sure EQMOD and the mount are OK.

I get this error message after calibration:



And here's a typical graph:



I have tried increasing the calibration time from the default 10 seconds to 20 seconds for RA and DEC both, but am getting about the same result. The "Distance" measurement shown during calibration is 0.0 or 0.0x where x is usually between 1 and 5.

My initial guess is that the something is configured wrong and the commands from Prism to EQMOD to cause movement during calibration are not causing any such movement. Pulse Guiding is enabled in EQMOD:



I'll post more setup info in the next message.

Thanks,
Rowland

[RowlandA]

Here is some additional setup info for my guiding issue:

My Telescope setup:



Guide Camera setup:



Message I get on connecting the Observatory indicating ASCOM Pulse Guiding selected:

[RowlandA]

Calibration parameters - I have tried with 10 and 20 seconds:



EQMOD Pulse Guiding parameters - initially the RA and DEC rates were 0.1x Sidereal, I boosted to 0.7x during the run from which all these screenshots were obtained.
I also tried varying minimum pulse width from 20 to 50 and didn't see any difference.



I'm sure I have something simple wrong here, but after two nights of trying I figured it was time to ask the expert !

Thanks for having a look,
Rowland

[Hamza Touhami]

Hi Rowland and welcome to the family.

I would like to point out that I appreciate it very much how you answered your question. I will put notes in red below:

Calibration parameters - I have tried with 10 and 20 seconds:


I suspect that the FFT intercorrelation has not identified your stars properly to see their motion. Can you please uncheck the box in the autoguider parameters above called "Auto/Star field detection" ? This will cause a manual click with the mouse on the same star of your choosing. Worth noting, are you using an ST-4 cable between the guider and the mount by chance?

EQMOD Pulse Guiding parameters - initially the RA and DEC rates were 0.1x Sidereal, I boosted to 0.7x during the run from which all these screenshots were obtained.
I also tried varying minimum pulse width from 20 to 50 and didn't see any difference.



I'm sure I have something simple wrong here, but after two nights of trying I figured it was time to ask the expert !

Thanks for having a look,
Rowland

[RowlandA]

Hi Hamza,

Thanks for your reply. FYI, I am -not- using an ST4 cable from the camera to the mount.

Our weather forecast is not good for the next few nights, but I'll try your suggestion ASAP.

In one of my earlier attempts I did have the "auto star recognition" checkbox unchecked and used the red crosshairs to pick a star but got similar results (failed to calibrate for same reason). I did make a couple of changes between then and my most recent attempt - mainly around setup of the mount and camera in an attempt to properly configure it for ASCOM pulse guiding through the mount so it is worth trying it again without auto-detect of a star.

Otherwise, does my setup look correct as far as using ASCOM pulse guiding to the mount?

Prism is working hard right now taking darks and bias frames. I did try an evaluation last Fall and had a number of crashes so I gave up, but it's been stable now and it was probably some hardware or software glitch on my end the first time I tried. Hoping it all goes well this time!

Thanks,
Rowland

[Hamza Touhami]

Thanks for giving it a second chance Rowland, I appreciate it. the dead giveaway of guider issues is the amount of motion between guider calibration steps. If it something like 1 or 2 pixels of motion, something is preventing PRISM from actually moving the mount. I had an EQ8 and ran beautifully with PRISM for months.

[RowlandA]

Hi Hamza -

We got some decent skies tonight and I continued the test. I turned off the "auto star detection" in the Calibration setup and got some better results.

This time the RA and DEC axes showed movement during the calibration images, but the parallelogram didn't close on the last leg. Calibration failed, but now I believe I know what the problem is. I am evaluating Prism on a temporary setup, and I'm sure now that the Sirius EQ mount is overloaded and having trouble moving.

I have a Losmandy GM811G mount on order and this is the mount where I would be using Prism. I don't have a delivery date yet, I'm guessing 4 to 6 weeks. I'll see if I can make progress until then with a more lightly loaded SIrius EQ mount.

Do you have any reports of Prism working on the Losmandy mounts with the Gemini 2 controller? I may not have much time left on my evaluation license of Prism once the Losmandy gets here.

I do like Prism though, it's very nice to have everything in a single program.

Thanks for your help,
Rowland

[Hamza Touhami]

Yes, many users use the G11/Gemini 2 without a hitch, I had the G11 and liked it very much.