I've got a CEM120EC2 and it's been working well with Ekos.

Hi,

I have a GEM28 and no issue except the park position setup as the home position, but the setting seems to be not saved par the handset. The driver is not the problem.

Fred,

If you don't mind, I've got a question about my iOptron GEM28 mount with Ekos.
I started with my RPi4/8G with the Astroberry 2.0.4 image and had some issues with the meridian flip. I now am trying with Stars 2.6.4 stable on Ubuntu 22.04.2 LTS. It looks like both have this issue that sometimes Ekos will initiate the MF, but it immediately says that the MF completed and failed.

My issue seems to be that sometimes the pier side is wrong in the Ekos mount tab. Do you know where Ekos gets that info? Is there a way to force it to sync up with which side the mount actually is?

As long as the pier side is correct in Ekos, it looks like the MF will work.

Thanks,
Pete

Welcome to the forum, Pete!
Could you please post your logs. Without them it's difficult to help. Here is an explanation how to do this:
www.indilib.org/support/logs-submission.html
-Wolfgang

Pete,

First, I agree with Wolfgang that having a look at the logs will help diagnosis.

The only times I've had trouble with meridian flips has been when I haven't had the meridian flip settings established correctly. There are other threads that cover this but, for my part, I set the mount to STOP at 5 degrees past the meridian (can be done via the mount's handset or via the 'Meridian Behavior' tab on the INDI Control Panel for the mount). In the Mount tab in EKOS I set the Meridian Flip if HA>2 degrees. The key is that the EKOS setting is 2 or 3 degrees less than the mount setting. In this way EKOS will control the slew (meridian flip) rather than the mount setting. The difference of 2 or 3 degrees is to allow enough time for any long exposure to complete before initiating the flip.

I've spent no time on the pier side settings and can't really help you there if that turns out to be the problem. As long as the time, location, and home position are established I've not had the problems you've indicated. Again, the log files may provide some clues.

Here's a log file with MF failures. I'm not sure what verbosity was set when this happened, hopefully there's enough info in it. I'll bump up the level and see if I can get it to happen again.

I've had this mount for a couple of months, so I'm still learning about it. At first I wasn't aware of the Meridian Treatment settings in the HC. It was defaulted to 'stop at position limit' and the position limit was 0 in the HC; of course that caused MF (and autotracking) to fail. Now I have the HC position limit set to 10 deg and in the mount tab of Ekos it is set to flip at +5 deg.

Thanks,
Pete

Hi Pete,

One quick question - looking at your log, it shows you are running 3.5.5 (with a build date in 2021). In your original post you had indicated problems with 3.6.4 (actually the post said 2.6.4 but I assume you meant 3.6.4). Can you clarify?

Fred,

The log I attached was with 3.5.5 (Astroberry Server 2.0.4). So yes, an old build. I built a SD card yesterday with Ubuntu 22.04.2 and KStars 3.6.4 and I noticed that it started out with the pier side being incorrect, but I don't have logs of that build failing the MF. I'll see if I can reproduce with the newer build.

I should have stated initially that I think its 90% likely the issue is either an incorrect setting or something I'm doing wrong.

Thanks,
Pete
--
iOptron GEM28, Redcat 51, Nikon D7500, WO Uniguide 32/120MM, ZWO ASI120MM Mini

Hello,

I have an iOptron GEM28. The last use with V3.6.4 and the scheduler, the MF didn't run well. After it, the object was not in the right position. And I have to delete all images taken after. And more, I think guiding was out of order also.

It was very curious. I was confident, cause before, with 3.5.9, the MF was perfectely executed.

The weather being very bad, I can't do another try. Next time, I'll pay attention to the log.

Pete,
when reading your logs it looks like you have the typical problem with meridian flips that EKOS calculates your mount being very close behind the meridian, but your mount firmware assumes being before the meridian. This is typically a problem that location or time do not 100% match between your mount and EKOS.

As a resolution I would recommend that you a value of 0.5 degrees and not to 0.0 as it is currently.

Btw, I cannot confirm that the INDI shows the wrong pier side. INDI reports Pier Side: West (pointing East), which should be correct.

HTH
Wolfgang

Wolfgang,

Thanks for looking at the log. I thought that I had the flip set to occur after the meridian had occurred, but I was playing with settings in that run. Is the value you're talking about 'meridian diff' ? Is that value in hours?

I'm attaching another log that has a MF failure, this one has:
I have a GPS dongle connected to the RPi, it appears that Ekos sends the time & location to the mount since I've configured KStars to use GPS for location and time. I see this in the log:But I'll double check that when I start KStars.

Thanks again for your help. We have clouds for the next few days, so I"ll be doing indoor testing to see if I can reproduce this again.

Pete

Hi Pete!

Based on your comments it looks like you know this but if it helps in any way, here is the language from the INDI driver page for iOptron mounts. I've generally set the EKOS MF at 2 degrees past and the mount's MF at 5 degrees - that difference more than covers the longest exposure I might expect to take.

FROM THE INDI DRIVER PAGE:
You have to let the mount track some time AFTER CROSSING MERIDIAN, otherwise MF is not going to happen. In iOptron driver, the Meridian Behaviour setting Flip or Stop does not matter here, since Meridian Flip will be triggered by the client (e.g. Ekos); but the Limit you set does matter. Basic rule is:

0 < Client Limit < Mount Limit

Example: set Client (e.g. Ekos) to trigger MF 3° after crossing the meridian, and set mount limit to 6° after crossing meridian. You must set the 6° in the iOptron INDI driver.
Ekos limit should be greater than 0, because Ekos and mount must exactly agree on which side on the meridian we are: allowing to track some degree after crossing it, relaxes the precision needed and accounts for small difference in models and approximations between Ekos and mount firmware.
Mount limit should be greater then Ekos limit, because some time is usually needed to complete the running capture when filp time occurs (should be: MOUNT LIMIT - EKOS LIMIT > LONGEST EXPOSURE PLANNED). And MOUNT LIMIT should be small enough to avoid the mount smashing your equipment on a tripod leg.