Losmandy GM811 / Gemini 2
NINA
Last night was the first time I tracked an object through the meridian. I had NINA programmed to flip 5 minutes past the meridian, with a maximum of 10 minutes. Use pier side was ON.
I'm using a refractor, so my safety limits are:
EAST=94
WEST=95
WESTERN GOTO=0 (I think... I found it set to 0 but I had it set to 2.5 the last I looked)
The target crossed the meridian and when the exposure completed (I was using 8 minute exposures, so between zero and 8 minutes after meridian crossing), NINA said it was doing a meridian flip. All the steps completed and it re-centered and began tracking again. However, the meridian flip never actually occurred and a couple minutes later the scope tracked into the western limit and stopped. I backed it up manually, did another GOTO from NINA and it flipped and I continued imaging normally.
I am trying to figure out why the flip never actually occurred in spite of NINA saying it did. I assume NINA does a meridian flip simply by commanding a GOT and my guess is that the issue is my western safety limit in conjunction with the NINA settings?
If I am analyzing this correctly, with a western limit of 95, I have 20 minutes of tracking past the meridian before it tracks into the limit and stops. I have reconfigured NINA to perform a flip if the object is between 2 and 18 minutes past the meridian and I have left the western GOTO limit at 0. Am I correct in assuming that if an exposure finishes with the object between 5 and 18 minutes past the meridian, NINA will do a simple GOTO.... which should succeed because the object will be between 5 and 18 minutes past the meridian (with a western goto limit of zero)? And if an exposure finishes with the object at 4.9 minute past the meridian, NINA will begin a new exposure that will (with 8 minute exposures) leave the object at a max of 13 minutes past the meridian.... which will trigger a flip on completion?
Kinda makes my head explode ;)
Side question..... what is the easiest way to unlock the mount if it has hit the safety limit and stopped? Can this be done remotely or does it have to be at the HC? I went out to the scope and could not back it up with the HC. I had to do a PARK and then stop it part way. At that point it resumed tracking and responded to a SLEW from NINA. Since my target was now west of the meridian, the mount flipped and everyone was happy. Was there an easier way?
Paul
--
Paul Goelz
Rochester Hills, MI USA
pgoelz@...
www.pgoelz.com
