Re: Odd APCC-PRO behavior with horizon limits "Time before limit reached" #APCC

Ray Gralak


I guess it is possible there is a bug in this calculation. When I get a chance I'll try to reproduce the values from your horizon limits file and the sky position captured in your screen shot. I am not sure I have all of the information though as you only provided the ASCOM log and not APCC or PNT files


-----Original Message-----
From: [] On Behalf Of Eric Weiner
Sent: Sunday, December 26, 2021 11:56 AM
Subject: Re: [ap-gto] Odd APCC-PRO behavior with horizon limits "Time before limit reached"


It's not obvious to me how that could occur without some other artifact. I'm open to suggestions from those
with computer science backgrounds. To me it seems like APCC did the calculation wrong at some point, and
I just happened to see it before changing tabs. I could be totally wrong of course. Also, I'm fairly certain that I
switched back and forth between the Meridian and Horizon tabs when I first noticed the horizon limit error. I
wanted to see if the Meridian limit was being reported correctly, which it was. I can't be certain because it was
getting late (and I had a few drinks over Christmas day), but I think the "correction" occurred when the limit
was reached. I just happened to be looking at the Site tab when that happened. The 23' 59" time remaining in
the screenshot was taken when I first noticed the error, so easily a couple tens of minutes before the
correction occurred.

For completeness, the horizon countdown timer was operating when it was displaying the incorrect "time
before limit reached." It wasn't just a static screen, and we're talking a several hour delta between what was
displayed and what the actual limit was. In hindsight I wish I would have let it run out to see if it triggered the
"Stop Tracking" command. I don't usually monitor an imaging session, so I have no idea if this has happened
before or if it was just a one-off fluke. If the situation recreates itself I'll let the limit timer expire to see what

I was paying attention this time simply because I was exercising a fully automated N.I.N.A. advanced profile
for the first time, including a Dec Arc model (Awesome plug-in Dale, thanks!) and Smart Meridian Flip. The
APCC GUI was sometimes minimized, and sometimes not. It's set to stay up front when not minimized, so
there were plenty of opportunities for the screen to refresh itself. I was hours into the run before I noticed it.

As a sidebar, I highly recommend N.I.N.A. for those who haven't tried the latest incarnation. It has come a
long way, very elegant. I was a SGP user for several years before trying N.I.N.A. 2.0 after reading comments
on it from other AP owners. The versatility the advanced profile sequencer provides is really quite impressive.

I'll keep an eye on this moving forward.


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