Re: Dec limit in Mach2

Roland Christen


I have alerted the members of our software team about your issue. It may very well be a simple error in the user entries in APCC. We had one other user last year that had a similar problem and it was fixed in his APCC entries, but I don't remember what specifically we advised him to look for. We'll get your mount running properly with APCC, so hang in there.


-----Original Message-----
From: Luca Marinelli <photo@...>
Sent: Sat, Jan 30, 2021 3:07 pm
Subject: [ap-gto] Dec limit in Mach2

I have been battling an issue with the Mach2 that is difficult for me to pinpoint. I am using the Mach2 with APCC Pro, I finish an imaging session by parking the mount to Park 3. When I start APCC at the beginning of an imaging session, i initialize the mount by unparking from latest park position. The coordinates reported by CP5 are correct. When I launch the imaging run and start by slewing and centering on the target via plate solving, often the mount will hang mid-slew. AP ASCOM and APCC will report that the mount is slewing but the motors are not running. There is usually an error message of motor stall and also a notice of Dec limit reached. I have not set up Dec limits, the mount is not hitting against the mechanical Dec limit.

Last night to avoid this problem I started the session by issuing a Find Home command immediately after unparking from Park 3. The slew and center to the target went well and the imaging run started without errors. This morning when I went to shut down I found that the mount was parked in place close to Park 3 but not exactly. There was a fault triggered northern limit reached error message. I unparked, issued a Find Home command, parked at park 3 and all was well.

I am not sure if it is an issue with the CP5 or APCC Pro. It appears that the mount somehow gets lost easily and it requires frequent Find Home commands, even without having issues incorrect recals. I wonder if there are still leftover settings from when I used this computer and APCC Pro with the Mach1 that was recently replaced by the Mach2 that are causing these issues.

I am attaching a couple of screenshots demonstrating the messages and problem and a link to log files from the last few sessions.

Thank you,


Roland Christen

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