Meridian flip issues SGP/EQMod

Hi Tim,

I have some doubts:

A) Don’t use any pointing model at all. Let plate solve manage the whole alignment process.

D) Set the meridian flip at 2 degrees past meridian. (8 minutes in later SGP releases)

E) Set the mount meridian software limits at greater than 2 degrees.

Ponit A)… Where is that option? Eqmod or SGP?
Point D)… That’s inside SGP. OK
Point E)… Where is it that option? Is it in SGP? In Eqmod?

I have a Neq6 Pro 2 mount, and uses it through Eqmod.

Thanks
Fernando

It’s better to use Version 1.28m and use the Pointing mode.

Physical only works half the time, for hour angles in the range -6h to +6h. For the other half of the hour angle range it’s wrong.

I realise that the good hour angle range is the area that people use most of the time but there are traps at each end. If your sequence happens to finish slightly after +6h then the pointing state suddenly changes and SGP fails.
I’m not sure what happens if you start slightly before -6h but the pointing state will be wrong and SGP could easily struggle.

IMO it’s a shame that EQMOD has so many options for pointing state. The only one that complies with the specification is Pointing and AFAIK the only version for which that works over the whole of the Earth is version 1.28m.

Apparently the other modes are to satisfy applications that need different interpretations but that just means that there are two applications that are wrong.

There’s a case for allowing for cone error in the pointing model. This will mean that a sync on one side of the meridian will be close when a pier flip is done. Without this a mount that’s synced in one pointing state could have an error of twice the cone error when a flip is done.

Chris

Hi Fernando,

A. In EQMOD in the center of the main page under Alignment/Sync click on the litttle page icon to open your pointing model. Delete all your alignment lists and untick all the choices that add new alignment points. Back on the main EQMOD page set the user interface to dialog based.

D. In SGP open the Equipment Profile Manager and under “Telescope” tick “use Auto Meridian Flip” . Click the box next to it that says “SET” . This opens the Meridian Flip Options. If your version says “Degrees past meridian to flip” put 2. If it says “minutes past meridian to flip” put 8. Tick auto center meridian flip.

E. This option is a safety feature in EQMOD.to prevent the scope crashing into the mount.if the meridan flip fails for any reason. Its found on the main page of EQMOD. Under Mount Limits Tick “Enable Limits”. Click on the little wrench symbol next to that to open up the box to set your limits. You will have to test it but just make sure you don’t set the limits so they kick in and park the mount before the pier flip works. You can easily set this up indoors.

Hope this all makes sense…

Sorry for the question, but I used always physical and I never had an issue, an imager on the same continent had this issue and then someone mentioned the fix of selecting 1.28 this is confirmed to be working …

But I can’t figure out that -6 to 6 Ha is working, then how can one have the issue … our objects are always in that range … so just for my understanding can someone explain the edge case?

/Yves

Thanks for your help!! I currently have version EQMOD 1.27. I have to switch to a new version?
Thank you,
Fabiomax

Yes, the fix was applied to 1.28m. You can get this version from the file section on the EQMOD Yahoo group. Then after you install this version select side of pier to pointing. Also make the other changes as in post 5.

Thanks Tim,
first of all I apologize because I’m not good with softwares :frowning: . I could not find this version on the yahoo group. But I found this (versione k):

Do you think that’s okay?
Thanks again,
Fabiomax

1.28k is OK if you are in the Northern Hemisphere, not in the South.

Select the “Pointing” SideOfPier mode.

Chris

Chris,

So which version is recommended for the south hemisphere, I use 1.28m as per previous posts and haven’t noticed any problem

Thanks
Uri

Thank you Chris,I installed k version and I set pointing. No limits selected on eqmod
Cheers,
Fabiomax

Thank you Tim for your answer.
And sorry for the delay in thanking you!

I had other different problems, but finally checked all successfully.

But I had to do a change: I had to set the eqmod settings in Jnow, instead of j2000, mainly because Thesky6.

Thesky6 has no way of setting the epoch (or I didn’t find it). With eqmod 1.28m set in J2000, when I slew to any target with TheSky6, the target is always placed with an offset. Never centered. And when I sync with SGP the scope position, I see that the solved coordinates correspond to those in Jnow!.

I changed last night eqmod settings to Jnow, and then the slew is perfectly centered. The star is in the middle of the image, with no offset.

And made a little sequence with 4 targets without problems. But I couldn’t check the meridian flip because of the clouds.

I don’t really now if it’s mandatory to set eqmod in J2000 or its Ok also in Jnow, as SGP understand it.

Thanks
Fernando

1 Like

Hi Fernando - The key is to get all your programs/platesolvers using the same epoch. It was recommended that EQMOD users start with J2000 because the majority of other programs and plate solvers are using J2000 as the default. So, this kept everything in the same epoch. Certainly EQMOD can also run successfully in JNOW. Just make sure all other programs and plate solvers are also using JNOW. Sorry for any confusion.

Hi,

Hope someone can help with failed Meridian Flip.

Eqmod 1.28
SGP: 2.4.3.21
Log file: Dropbox - File Deleted

I have inserted “[Uri]” in the log file in relation to the following issues;

[14/12/15 3:02:21 AM] [DEBUG] [Telescope Thread] [Uri] ASCOM Telescope: Invalid Operation Exception in Sync : SyncToCoordinates() RaDec slew is not allowed while scope is not Tracking. (System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. —>

What is the meaning of the above error ?

[14/12/15 3:02:21 AM] [DEBUG] [Pier Flip Thread] [Uri] Meridian Flip: Solve and Sync was Successful

Then later in the log file

[14/12/15 3:02:27 AM] [DEBUG] [Pier Flip Thread] [Uri] Meridian Flip: Telescope failed to perform meridian flip

What was the reason for the flip failure ?

Many Thanks
Uri

Usually means your mount was parked, but I can’t say for sure. Would need the ASCOM logs to see what happened. The only visibility we have is that your mount is no longer tracking, so as far as SGPro is concerned, it is done.

No request to park the mount was sent from SGPro…

Thanks Ken,

Yes, the telescope parked, but why ?, is that an issue with Ascom/Eqmod (I wouldn’t want to bother you with this issue if it’s nothing to do with SGP)

I couldn’t find any log file under my documents\Ascom folder other than some Ascom.Profile files which show date/time as of yesterday morning (I have updated to version 6.2).

Are the log files stored somewhere else ?, under what name ?

Thanks again
Uri

Ken,

I have the same issue as Uri. Can you please indicate what the issue might be or settings that need to be tweaked.

Regards,
Stephen

I’ve spent some time looking at the log and things seem to go wrong at about 02:58. There are messages from PHD saying that it is having trouble guiding -

“Your Max RA Duration setting is preventing PHD from making adequate corrections to keep the guide star locked. Increasing the Max RA Duration setting will allow PHD2 to make the needed corrections.”

This is an indication that tracking has stopped. PHD is trying to compensate by issuing ever larger guide corrections.
The mount is just past the meridian.
Could there be a limit in the mount on how far it can track past the meridian? If it tracks too far it stops tracking.
SGP knows nothing of this so when it issues a sync command it fails because the mount is not tracking.
Does this make sense? If so the solution is to allow the mount to track further past the meridian.

Chris

The other event if you hit the EQMOD meridian limit is that the plate solve fails because the stars show drift, then SGP goes into recovery mode, but never takes a frame which can be plate solved and eventually aborts the sequence. You can check if this occurred by looking for the plate solve frames which are stored in user/appdata/local/sequencegenerator/temp after your SGP session. (Note these files are deleted each time you run SGP). If the plates show drift, that’s probably what happened.

Scott

Thanks very much Chris,

Here is the screenshot of PHD log viewr which indeed indicates aproblem has occured at that time. I think you may be right, Interestingly, I have done several indoor test and never had a problem.

I use Synscan 3.36 on AZEQ6 mount. in the setup I see ‘Auto flipping’ set to 'Auto flip. I’m not sure whether this may be a problem, I use EQmod so aren’t all mount settings ignored ?

Abd BTW, is there any Ascom or EQmod Log ?

Thanks Uri

You need to check with the EQMOD people about what logs they produce.
That PHD graph is interesting, the run away in Ra is pretty obvious. The way it starts and is so uniform indicates that it is the mount has stopped tracking.

A short plate solve exposure might still be able to solve and in this case it is solving.