Re: Occasional error in guide speed - massive overcorrections


Just to update this, in case anyone else runs into the issue:

I found at least one cause of this pulse guide rate discrepancy. Seems if I issue any manual guide commands directly through APT, it will set OnStep pulse guide rate to whatever APT is configured for "m" or "s".  PHD wont realize this has changed and will attempt to guide expecting the normal slower rate.  To fix the issue on the fly, I have used the app to manually guide at the normal 0.5x rate, after which PHD2 guides correctly again. Additionally, you can manually guide through PHD2, however you need to change the guide rate and then change it back to the desired rate.   If you don't change the rate away and back, PHD2 will assume its already guiding at .5x and wont issue the command to set the guide rate.  At least that's the best I can figure.

So to sum up, its not an issue with OnStep, but a conflict between two different programs setting the guide rate and not knowing the other has changed it.

On 5/20/2021 8:11 AM, GuitsBoy via wrote:
Hi All -

Ive searched on this topic a few times in the past, but not really getting any hits.  Please excuse me if this has already been covered, and I simply missed it.

I'm experiencing a strange issue on very rare occasions, and I cannot seem to find a pattern that causes this to happen.  I'll be all set up, and happily image my first target for the night using APT, PHD2 and Device Hub with the ASCOM driver. I'll finish my first run of subs, do a goto to the next target, and star guiding.  As soon as PHD2 issues the first small correction, the mount makes a MASSIVE correction, as if its guiding at full slew speed.   Ive attempted manually guiding at .5x, Ive attempted disconnecting the mount and issuing the :R1# command through Arduino Serial Monitor.  Ive disconnected and reconnected each program.  Nothing seems to help until I reboot the laptop, and power cycle the mount, starting from the home position.    This is really no big deal to do on occasion, since my telescope is just a few feet from my back door.  But how do people with remote observatories handle this?   BTW, I've experienced this same behavior with multiple onstep mounts, and different laptops, so I don't believe its isolated to my specific build, unless something was copied between the two.

Has anyone else experienced this?  Is there a common cause?  Any suggestions on how I can help narrow down the suspected software glitch?


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