PulseGuide command to mount has failed

[Stephen Martin]

After many months of successful guiding my C8 on NEQ6 mount with 120mm guide scope via NINA and GSS, I started getting the above error message in PHD2 with both dec and ra running away to crazy high numbers. Tried a new calibration which was successful and guiding worked for a few mins, but then the error message reappeared again. Also tried changing the USB cable and the USB port on the PC but no success. Mount responds to commands OK and slews to target and everything fine, so I don't think its the EQDIR cable. Any suggestions to try? Logs here...

https://openphdguiding.org/logs/dl/PHD2_logs_aKA2.zip

Thanks

Stephen

[Brian Valente]

Hi Stephen

PUlseGuide command failed is a fairly common issue when the mount doesn't respond in a reasonable time. This can be tricky to hunt down: could be connectivity issues (USB cable, port, etc.), software not responding, etc. There were something like 14,000 pulse guide fails, so until you can hunt down the source of this and resolve it, it's likely to continue being an issue. Is it possible to use an alternate driver just to confirm it's not within GS Server?

Aside from that, your guidelog shows some other issues you should address:

1. you are not using darks or defect map for your guide camera, highly recommended

2. 1 sec guide exposures is pretty short - can you increase that a bit? the reason i ask is because:

3. you are getting a lot of lost guidestars. When this happens during calibration (it notified you of this issue) you should re-do the calibration until there isn't a lost star event. It resulted in a questionable calibration. 

otherwise, your guide star is varying in signal quite a bit that results in many lost star events. It looks like you had highly variable seeing conditions towards the end of your night:

(star SNR is in yellow: it should be roughly a straight line)

If that's passing clouds, not much can be done with that, but increasing your exposure time can help here

Brian

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[Stephen Martin]

Hi Brian

Thanks for the response, I appreciate you taking the time to help.

I had switched from EQMod to GSS as I was getting some odd mount behaviour with EQMod previously that went away after switching to GSS. I will try tonight clear skies permitting to use EQMod and see if that works or not. 

I normally do use the dark library but this must have become deactivated after I switched the camera to another to try and rule out an issue with the guide camera/cable.

The conditions weren't great with lots of passing cloud and I suspect that was the cause of the lost guide stars. I will try a longer exposure though. The calibration attempt was just me trying to check if it would move the mount appropriately, which it seemed to. Here is a log from my last successful session. https://openphdguiding.org/logs/dl/PHD2_logs_kyCR.zip 

If it works tonight with EQMod I will try a reinstall of GSS from scratch. And if it is still problematic with EQMod I think I'll have to order a new EQDIR cable.
Thanks

Stephen

[Bruce Waddington]

Just to add to what Brian said - I consider this to be a bug in the driver even though it might not be the primary cause.  With this driver, once one of these timeout conditions happens, the driver continues to report that the mount is still moving - forever.  We don't know whether that's true - seems unlikely - but there should be a timeout and "stop" procedure in the driver itself.  We don't know whether the underlying reason for the problem is a comm failure between the driver and the mount but I think the driver should be more robust than this - we don't see other drivers with this behavior.

Good luck,

Bruce

[Rob Morgan]

Stephen,

if you continue to see issues you might try posting the GSS session logs to https://gss.groups.io/g/main/topics

--Rob

[Stephen Martin]

Thanks for the suggestions. Last night I had a few hours of clear skies to start with at least. I tried my usual setup with GSS first and after a while started to get the pulseguide command error message and Dec flew off the guide graph. I switched to using EQMod instead of GSS and had issues with the same error message and also NINA losing connection to the mount. I suspect then its a communications issue with either the EQDir cable or the PC USB hub? Here are the logs from last night
https://openphdguiding.org/logs/dl/PHD2_logs_NeMA.zip

Thanks

Stephen

[Brian Valente]

Stephen

>>> I suspect then its a communications issue with either the EQDir cable or the PC USB hub? Here are the logs from last night

Pulse guide failing is not uncommon, there's nothing from the PHD side to indicate what is the cause of it, we only know the mount did not respond in the time expected. 

It's definitely worth trying a new cable, switching ports on your computer, inspecting/cleaning the cable contacts, etc.

To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/0baabf22-a714-4389-891e-1ccff9d3169dn%40googlegroups.com.