Ekos auto meridian flip says it does, but doesn't

[JamesF]

I have a strange problem with Ekos/INDI and a NEQ6 at the moment where the mount is configured to auto-flip in the middle of an imaging run.  When the time comes (set to happen when the hour angle of the target is greater than 0.2 hours), Ekos waits for the current sub to finish, logs that it is doing the flip, reports that it was successful and then re-aligns and restarts guiding before continuing with the next sub.

Only the mount has not flipping moved.  It does not flip at all and I have no idea why.  If anyone has has any smart ideas what might be going wrong, please do tell.

I have a second mount configured exactly the same (as far as I am aware) that seems to work exactly as I would expect.

James

[david_taurus83]

I had that as well with my AZEQ6. I'm pretty sure when I first setup the scheduler it worked first time. But after that it didnt and I never worked out why?

[JamesF]

So if I'm going mad, I may well not be the only one :)

I'm not sure that's progress, but it may be reassuring :D

James

[wimvb]

Works for me (AZ-EQ6 with eqdir cable and EQMOD driver). Although I must admit, it hasn't always in the past, for reasons that were beyond me.

I do regular updates of my software.

Have you tried switching the computers that control the mounts? Ie, computer from mount 1 (not flipping) on mount 2 (flipping) and vice versa? That should tell you if it is the mount (including cable) or the software that is to blame.

[MCinAZ]

Do you have any way to see traffic between Ekos and the mount driver or between the driver and the mount?

[vineyard]

Hello, not sure if its the same problem, but I've been having problems w EKOS, guiding and I think meridian flip as well.

It starts off fine, and then - judging by the records the next morning - at some point the mount moves, tries to recalibrate, the guide exposure fails and the whole sequence aborts.  Judging by the time that this happened for the target last night, I think it may be the meridian flip that's doing it?  Which is strange b/c its been fine in the past (and I haven't knowingly upgraded my installation)?

I'm going to rummage on indilib forums to see if there is anything going on at the moment.

Cheers,

Vin

[wimvb]

1 hour ago, vineyard said:

Hello, not sure if its the same problem, but I've been having problems w EKOS, guiding and I think meridian flip as well.

It starts off fine, and then - judging by the records the next morning - at some point the mount moves, tries to recalibrate, the guide exposure fails and the whole sequence aborts.  Judging by the time that this happened for the target last night, I think it may be the meridian flip that's doing it?  Which is strange b/c its been fine in the past (and I haven't knowingly upgraded my installation)?

I'm going to rummage on indilib forums to see if there is anything going on at the moment.

Cheers,

Vin

Clouds can also cause this. 

Anyway, try to do the flip when the mount is well PAST the meridian, so the mount won't flip back and forth during attempted platesolving & goto. 

[vineyard]

1 minute ago, wimvb said:

Clouds can also cause this. 

Anyway, try to do the flip when the mount is well PAST the meridian, so the mount won't flip back and forth during attempted platesolving & goto. 

Thanks wimvb.  I will keep an eye on that - I don't think there were any clouds last night here (v clear, and the last subs taken show no sign).  I thought the flip just happens automatically (is it possible to control or calibrate when it happens)?

Cheers!

[MarkAR]

51 minutes ago, vineyard said:

(is it possible to control or calibrate when it happens)?

Cheers!

Yes to a certain extent.

In the mount control, tick meridian flip, tick hours, input the time past MF you want. Its decimal so 0.1 will be 6 minutes past MF.

The mount should then auto flip once it has past the time set and finished its current exposure.

I've set mine to 0.05, others up to 0.15 or more.

[JamesF]

I think the change Wim suggests helped for me, though I really need to understand the internals of the process a bit better -- how Ekos thinks it knows where the mount is and how the mount thinks it knows where it is.

I think once you've found a target, the mount largely just blindly attempts to track at the required rate (eg. sidereal) forever.  When Ekos decides the flip needs to happen, I believe it just says to the mount "go <here>" where <here> is actually exactly where the mount is currently pointing.  But, if in processing the request the mount determines that it's on the "wrong" side of the meridian, it will flip over.  If the mount doesn't think it is past the meridian yet, it won't flip.

So it looks to me as though the physical position of the mount, the mount controllers idea of the position of the mount and Ekos's idea of the position of the mount can all get a bit out of sync.  How that happens and what's required to correct it is something I'm not sure I understand.  I'd guess however that if you don't have a mount model set up and the position is way out when you move to your first target after starting everything up, perhaps that's an indicator that there's an issue.

By leaving the flip until, say, 0.1 or 0.2 hours after the meridian I guess there's thought to be a better chance that both Ekos and the mount will agree about which side of the meridian it needs to be.

James

[wimvb]

2 hours ago, JamesF said:

how Ekos thinks it knows where the mount is and how the mount thinks it knows where it is.

(Park position,) plate solve and time. If you point at a target, and that target crosses the meridian, so must your mount. But as you say, if there is an error in the position, that will affect the flip. If you use more points in your mount model in Ekos, goto accuracy will increase, and maybe that will improve the flip as well. 

Edited June 1, 2020 by wimvb

[wimvb]

3 hours ago, JamesF said:

By leaving the flip until, say, 0.1 or 0.2 hours after the meridian I guess there's thought to be a better chance that both Ekos and the mount will agree about which side of the meridian it needs to be

Very likely. Ekos sometimes gets confused when I try to point the scope close to the meridian. It tries to flip when it shouldn't. 

[JamesF]

2 hours ago, wimvb said:

(Park position,) plate solve and time. If you point at a target, and that target crosses the meridian, so must your mount. But as you say, if there is an error in the position, that will affect the flip. If you use more points in your mount model in Ekos, goto accuracy will increase, and maybe that will improve the flip as well. 

In my case, park is in the normal position, yet the first slew to a target with no mount model could be as much as fifteen degrees out after plate solving.  How does that happen?  Something must have a poor idea of where the mount actually is somewhere along the line.

James

[wimvb]

How about the accuracy of the observatory location and time zone? That shouldn't put the first goto 15 degrees off, though. That's a whole time zone! (in ra/longitude at least) 

[vineyard]

Hello, so I set the meridian flip in mount control to 0.1 hrs as per above suggestions (thanks Mark, I wouldn't have noticed those bits in EKOS otherwise).  And fingers crossed it seemed to have worked - got a full night's worth of data.  Hopefully that was what the problem was and it doesn't recur 🤞🏾  Thanks all!