Communication problem between PHD2 and Nitecrawler rotator?

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Kevin Quin

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Oct 22, 2025, 10:22:09 PM (13 days ago) Oct 22
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I think my rotator has stopped communicating with PHD2, even though the settings all look correct.  The other night guiding/tracking was perfect until NINA switched to my second target, then it started zigzagging - alternately giving move commands in RA and then Dec.  I suspect the problem is that PHD isn't getting notified that the rotator ran 45 degrees (as instructed) when NINA switched to the new target.  If anyone could see if this shows in the logs, I'd appreciate it.  THe log is here:   https://openphdguiding.org/logs/dl/PHD2_logs_UaB9.zip

My alternative theory is that the rotator (Moonlite Nitecrawler) is actually running in reverse from the direction it's supposed to run.  I need to have NINA's reverse setting ON to get the platesolve to work properly, and I suspect that setting isn't' sticky enough.  Sometimes when NINA starts up the sequence the reverse setting is set to OFF.
Thanks for any help.  

Kevin

Brian Valente

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Oct 22, 2025, 11:05:05 PM (13 days ago) Oct 22
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Kevin

I responded to you in the AP forums as well. the rotator is connected and registering the different angles, but your guiding is not correct. PHD has a reverse option as well, which may be what you need

In other words, if NINA rotator is working correctly, but PHD rotator is not, enable this. 

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Brian Valente

Bruce Waddington

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Oct 22, 2025, 11:49:48 PM (13 days ago) Oct 22
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Kevin, if you want to avoid going in circles and wasting a lot of time, please follow the full procedure for determining the correct value of 'Reverse angle' in PHD2:

https://openphdguiding.org/man-dev/Basic_use.htm#Rotator_Selection

Regards,
Bruce

Kevin Quin

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Oct 23, 2025, 9:51:32 AM (13 days ago) Oct 23
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Thanks Brian and Bruce.  I followed the procedure in the documentation when I first set this up a year ago, and found the only settings that allow both PHD2 and platesolving (to avoid having the rotator continuously "hunt" for the right angle but never find it) to work properly are to leave the PHD2 setting unchecked, the ASCOM setting unchecked, and the NINA setting to ON.  I'll run through the procedure again tonight.  Maybe a software update in one of the apps has changed something?  I'll try to find out.  

Bruce Waddington

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Oct 23, 2025, 11:45:28 AM (13 days ago) Oct 23
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Yes, the point of the procedure is to do a systematic, bottom-up set of tests to figure out the right setting at each layer in the software "stack".  I seem to recall that NINA might have made a change in this area some time ago but don't hold me to that.  Obviously, there is a solution to be had.

Regards,
Bruce

Brian Valente

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Oct 23, 2025, 11:48:28 AM (13 days ago) Oct 23
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>>>  I seem to recall that NINA might have made a change in this area some time ago but don't hold me to that.

I recall this as well (having my own rotators and dealing with this). I think Dale is somewhere around here and can correct us if needed



Kevin Quin

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Oct 23, 2025, 12:34:26 PM (13 days ago) Oct 23
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IIRC the move from NINA 2 to NINA 3 changed the direction of rotation.  But I've been using NINA 3 for at least a year.  Anyway, I should get some clear spaces between the clouds tonight to try this out.

Kevin Quin

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Oct 23, 2025, 10:21:23 PM (12 days ago) Oct 23
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After running through the test protocol, it looks like the correct settings are to have the reverse checked in PHD2 and the reverse in NINA set to on.  I could swear I've been running it for the last year with the PHD reverse unchecked.  But I replaced my PC recently, so maybe I got the settings wrong. Anyway, it's working so far.  

Bruce and Brian, thanks for all your help on this!

Brian Valente

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Oct 23, 2025, 10:24:56 PM (12 days ago) Oct 23
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Glad to hear you got it sorted Kevin, thanks for the update

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