Re: Testing homing limits resulted in motor stall errors with Mach1 #APCC


Roland Christen
 


'm afraid to repeat these tests as there could be potential problems with the hardware,
The "Motor Stall" warning will occur when unsafe limits are exceeded. This is not a warning that something is wrong with the motor or electronics, it is simply telling you that the software has turned off the power to the motors to prevent your scope from being damaged. At this time we use the same error code for all situations where the motor power has been turned off. It probably could be changed to indicate not "motor stall" but "motor power deactivated".  However, we have many other software challenges right now and this one will have to wait a bit. Be assured that nothing bad has happened to your electronics or the motors.

Rolando


-----Original Message-----
From: Leo Shatz <leonid.shatz@...>
To: main@ap-gto.groups.io
Sent: Fri, Jul 31, 2020 6:22 am
Subject: [ap-gto] Testing homing limits resulted in motor stall errors with Mach1 #APCC

Hello,

Recently I had a very good remote session with Howard Hedlund from A-P, who helped me to setup meridian and homing limits. I did some tests following the session and I've got some issues I'd like to raise here:

Meridian flips were fine, I didn't run in any problems with flips going the wrong way, as long as the red telrad circle was staying within meridian limits. However, I had motor stall event triggered a couple of times in the following situations:
 
- I've defined an action of "stop tracking and slewing and park in place" in homing limits and let the mount perform unsafe pier flip. When it hit the homing limit (well before colliding with the pier), the mount stopped, the message saying that limit was reached and dialog box flushing. Few moments after that, since SGP was configured to perform parking on its own, it tried to perform parking but failed as mount was already parked. I've seen a yellow flashing sign in APCC indicating an error and there was freshly triggered "motor stall" event.
 
- I did the slow slew (at rate x200) to move CWs up higher until it reached the homing limits, the mount stopped again with a message from APCC and there was another motor stall event.

After both cases I was able to unpark the mount and perform slewing in both axis (without manually turning power off/on to the mount).
 
I'm afraid to repeat these tests as there could be potential problems with the hardware, although it looks to me more like a software glitch under these circumstances. I hope it's not actually caused by a physical issue with the mount, but possibly a software issue where there is some race condition in detecting abrupt change in motor speed and control signal stopping the slewing/tracking at horizon limit.

Leo Shatz
 

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