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ASIAIR autorun randomly stops shooting

Posted: Sun Apr 19, 2020 2:55 pm
by herpmcderpington
When using autorun, the Asiair stops shooting after about 1 hour, and freezes for the rest of the night, even though it says "shooting" on the bottom right. I'm using version 1.4.3 on android. Is this a known issue?

Re: ASIAIR autorun randomly stops shooting

Posted: Tue Apr 21, 2020 9:43 am
by EricG
Are you sure it is not link to the guiding of with the dithering ?

Re: ASIAIR autorun randomly stops shooting

Posted: Tue Apr 21, 2020 8:52 pm
by Nordstern
I have a similar problem. auto run takes a picture and then it doesn't go on? does that not work with the dither function when guiding?

Re: ASIAIR autorun randomly stops shooting

Posted: Fri May 01, 2020 8:07 pm
by mmw09er
I had this problem last night for the first time... which is odd; the autosequnce stopped / got stuck after 14 captures. Everything worked fine the night before. There is plenty of space on the card so it's not a storage problem.

This morning I was doing some flats and it would get stuck after 2 of 5 captures. The Autorun log for the short session is below:

Log enabled at 2020/05/01 07:33:31
2020/05/01 07:33:31: Start Autorun
2020/05/01 07:33:36: Shooting picture 1#
2020/05/01 07:33:38: Download
2020/05/01 07:33:38: Shooting picture 2#
2020/05/01 07:33:40: Download
2020/05/01 07:33:41: Dither
2020/05/01 07:33:41: Settle
--- Capture progress got stuck here---
2020/05/01 07:34:04: Autorun Stop (I manually stopped it because the progress was stuck on 2 out of 5 captures)
Log disabled at 2020/05/01 07:34:04
Log closed at 2020/05/01 07:34:04

Any ideas why it gets stuck?


Re: ASIAIR autorun randomly stops shooting

Posted: Sat May 02, 2020 12:28 am
by W7AY
Hi Matt,

Short answer: turn off dithering when taking flats and darks.

What astro hobbyist calls dither is the process of moving the guide star by N pixels every now and then in the X and in the Y directions. (Different from dithering that we learn in college signal processing classes.)

This will cause all stars in the plate to land in a different pixel location to get around anomalies of CMOS sensors. When the stacking program runs, it corrects for the offsets. Once the mount settles down after the dither, the exposure in the main camera starts, and no further dither is applied until at least the end of that plate.

When you are taking darks and flats, there is no guide star. Or you are guiding on a stuck pixel. Either way, dither will never settle down.

When taking Lights, you have to make sure you understand the parameters in Dither Settings. Read up on Dithering in PHD2.

In short, do not exceed your mount's capability when you set the Stability and Settling time. If your stability selection is too small, a cheaper mount may not ever get there (so dither never completes). This can be cause by poor torque from the motors and/or poor backlash in the gears. This why legacy German mounts need to be carefully balanced and carefully biased. Balancing is required for good guiding too. This requirement is not needed for the mounts that use Strain Wave gears (the reason why I left a Takahashi mount for a RainbowAstro RST-135). The RST-135 has so much torque that you do not need a counterweight.

Clear skies

Re: ASIAIR autorun randomly stops shooting

Posted: Wed May 06, 2020 6:53 am
The reason why it stuck cause the dither never to settle down. In the new version, we set a 60 timeout on the settle. After that, the autorun will continue.

Re: ASIAIR autorun randomly stops shooting

Posted: Wed May 06, 2020 8:13 pm
by mmw09er
Many thanks, Ji.zwo and W7AY! I appreciate your explanations - they make complete sense! Clear skies! Matt

Re: ASIAIR autorun randomly stops shooting

Posted: Sat May 09, 2020 7:14 am
mmw09er wrote:
Wed May 06, 2020 8:13 pm
Many thanks, Ji.zwo and W7AY! I appreciate your explanations - they make complete sense! Clear skies! Matt
In v1.4.4 we set the dither settles down timeout to 60 sec. This would fix the issue.

Re: ASIAIR autorun randomly stops shooting

Posted: Tue May 19, 2020 1:03 pm
by mmw09er
OK... so finally after some additional attempts: I am still having the failed autorun procedure. Dithering is turned off. Last night's logs reveal it may be due to meridian flip complications. See attached log snippet imaging M51 from San Antonio, Texas. After 5 attempts to do the flip the unit gets stuck in a loop auto centering/platesolving. Any ideas?

2020/05/18 23:10:19: Shooting picture 20#. (the last photo that succeeded)
2020/05/18 23:14:21: Download
2020/05/18 23:14:31: Wait for Meridian Flip 1# (there were four more meridian flip sequences like these next few lines)
2020/05/18 23:14:31: Stop Guiding
2020/05/18 23:14:31: Stop Tracking
2020/05/18 23:21:06: Auto-Center Start
2020/05/18 23:21:13: Download
2020/05/18 23:21:23: Auto-Center 1#
2020/05/18 23:21:23: Mount slews to target position
2020/05/18 23:21:27: Expose
2020/05/18 23:21:34: Download
2020/05/18 23:21:35: Plate Solve
2020/05/18 23:21:37: Auto-Center Failed merid flip failed

The final meridian flip related log entry does something different
2020/05/18 23:25:41: Wait for Meridian Flip 5#
2020/05/18 23:26:41: Auto-Center Start
2020/05/18 23:26:48: Download
2020/05/18 23:26:52: Auto-Center 1#. (these last lines repeated over and over 1,200 times until I stopped Autorun.)
2020/05/18 23:26:52: Mount slews to target position
2020/05/18 23:26:55: Expose
2020/05/18 23:27:02: Download
2020/05/18 23:27:02: Plate Solve

I have come to think that maybe the Meridian Flip settings of the mount could interfere with things - what if it did a meridian flip before the ASIAir expected it, etc? Tonight I made change to my mount's settings (Ioptron CEM60) so that the ASIair should have a chance to manage the meridian flip before the mount is set to do it; and therefore should operate normally.

Re: ASIAIR autorun randomly stops shooting

Posted: Mon Jun 08, 2020 10:13 pm
by mmw09er
Replying to my own post to close this out ... as assistance to anyone else in the future.

I finally caught this in the act!

I verified that the ASIair was set to perform the meridian flip before the CEM60 was. I assume that if the CEM does it independent of the ASIair,then the ASIair would not know about the flip, and would therefore a) not plate solve to confirm it and b) later on it would attempt its own flip messing things up even worse. Better to let ASIair do it so it's workflow has a chance - i.e. plate solving upon completion to center the target again.

I think a point of failure I experienced last time - if clouds have come out or the focus of the primary or guider are affected by the flip, then ASIair cannot correctly verify the object is centered after the flip and therefore imaging workflow does not resume.