The last couple of nights I was shooting the horsehead nebula from silicon valley, and it crossed the meridian around 11:15pm (though it's altitude was no where near 90). I had mount limits checked using 5-degrees and 90-degrees, but horsehead was nowhere near 90-degrees altitude (perhaps 50-degrees). The camera tab was taking a series of pictures, and the Phd2 tracker was tracking. Around that time, I started getting guiding errors with PhD2, though the sky was clear, and it should have had no issues. I switched over to the internal guider, and got the same issues--where I believe it said it couldn't correct RA. I Also, I believe it had crossed the meridian and didn't do the automated meridian flip I expected.

All these error went away when I disabled the mount limit and manually forced a meridan flip by asking it to track to something on the other side of the meridien (is there a way to simply request a flip, or an early flip?).

I'm a bit confused on the mount limit altitude meaning. Clearly what's important is preventing the camera end of the scope from hitting the tripod legs--so the scope's altitude when it's pointing at something crossing the meridien I suppose is 90, even if it's tracking something whose altitude is << 90.

Clearly, I suspect that the limit was somehow disabling the RA corrections and the meridian flip (though the mount was still tracking). I have no logs or other useful info for you. I'm sure the limit was set at 90-degrees. Sorry about that. If there's some kind of pilot error here, sorry, please let me know what I got wrong. Or, if you want some logs etc, I can try and re-create this and turn on some kind of logging as you request (please give instructions). I am running the latest stellarmate OS release on a raspberry pi.

Hy

Do you have the logs? The limits would disable tracking if it hits the lower or upper bounds and this should be logged.