Help from EQMOD users


Looking over our requests for help over the last few months there is a distinct trend…

More than 75% of (mount / pointing / flip) issues are derived from users using EQMOD. I am not saying EQMOD is bad software, just that it seems to provide a lot of ways for users to find themselves in states that are not-compatible with SGPro. The others seem to be related to issues with other modeling software or just general confusion…

This has me wondering… for those of you out there using EQMOD successfully with SGPro, good centering, successful flips, etc, is anyone willing to write up an “EQMOD checklist” for use with SGPro. Is there any such thing? I know that there is the “physical” setting. Are there others that get folks in to trouble? Neither Jared or I have mounts that can use it so our help is feedback is pretty limited here…

I wish we were wealthy… but we would be willing to offer any such person (or group of solid contributors) a lifetime of free upgrades and SGPro addons for their work.

Autocenter fails after EQMOD meridian flip
Auto Meridian Flip not showing time to flip
Using SGP but PHD2 not recieving 'Side of pier'!

I am not experienced enough to write a complete checklist but would like to mention one point that seemed to improve my pointing greatly.selecting the nearest point transformation instead of the 3–Point Transformation. Because plate solving works so great recently I decide why go through the initial 3 to six star alignment, and just skipped it and tried to go straight thought to my target. I ran into some problem here with the 3–Point Transformation since after each plate solve and sync eqmod update the model but I guess since these point were all cluster around the target and did not have sufficient space between them it affected the accuracy badly. Nearest point seemed to resolve this

Object centering 101


I use eqmod with great success with sgpro. I am happy to document what I do and will try to answer questions. The first things that come to mind.

A) Don’t use any pointing model at all. Let plate solve manage the whole alignment process.
B) Set side of pier to physical.
C) Do not enable meridian flip in the eqmod software. Let sgpro manage the process.
D) Set the meridian flip at 2 degrees past meridian.
E) Set the mount meridian software limits at greater than 2 degrees.
F) Set the epoch in the mount as J2000
G) Alignment/sync user interface set to “dialog based”.


Is anyone managing to do meridian flips with EQMOD?

I agree with Scott’s recommendations. I would like to add to make sure you get your version from the files area in the EQMOD Yahoo group. There are a number of versions on the net that are old and often appear to be the latest version.


Same. I agree with everything Scott said with the exception of a pointing model. If I don’t use a pointing model and my Polar Align is far off SGP gives me an pop up window saying that the plate solve is very far off and could be incorrect. This requires user intervention and requires me to uncheck the end sequence box and then dismiss.

Setting the alignment/sync to “dialog based” is critical. If you get too many syncs the scope wont move when it plate solves and will just keep trying to it reaches the attempt limit.

One extra thing I have been noticing is weird things that happen occasionally when I use PEC with PEMPRO. For some weird reason EQMOD will lose the PEC. When this happens it does not track until I turn PEC and set it to Sidreal only or I reload the PEC data from pempro. So I just have one extra setup when I setup. When I unpark I just check EQMOD the PEC data is still there.


Scott’s list contains all the essentials.

The meridian limits to set can vary from the 2 degrees that Scott states, but the important point is to set them in Eqmod and to not enable the flip in Eqmod. Then set the meridian trigger in SGP (Degrees Past Meridian to Flip) less than that set as the soft limit in Eqmod.



The only setting I set differently is SideOfPier. I set it to V1.24g

Let me explain why. When I started using SGP (2 years ago?) Evething worked fine with EQMOD, then my laptop blew and I reinstall everything and the flips started to fail. The problem was that Chris Chilito (EQMOD developer) reworked the SideOfPier logic to improve it. I don’t remember the details but he was running some sort of ASCOM compliance test and the pervious logic was not ASCOM compliant.

Some people reported issues with SGP and he change the logic, he aded Physical or Pointing option (I don’t remember) But the issue didn’t go away, so he kindly put back the old logic as a third option, the old logic is V1.24g

Ever since I’ve been using this option without any issue.




I agree with Scott. With a permanent setup my mount is perfectly aligned. So far I only had a couple of successfull meridian flips, but the last time they all seem to fail for one reason or another. I still wonder why the Time To Meridian is different between SGP and EQMOD. It’s always that according to EQMOD, the meridian flip is passed it’s time while according to SGP, it’s still 15-30 minuten until the meridian. If I stumble upon something worth mentioning I will post it here, but so far Scott has all the essentials covered.



Thanks for the feedback and some great tips. A couple of additional notes from me.

I use eqmod v1.28b. Not the latest, but it works well so I have not updated.

My mount is a skywatcher AZEQ 6.

I have to setup the mount each time, so I polar align using the great drift tool in PhD2. As I am in the southern hemisphere, there is no easy polar star visible from the city. Once alignment is within 3", I start imaging. I also don’t bother with pointing model or PEC training. This takes about 15-20minutes.

I did initially have problems with meridian flips. Moving the degrees past meridian from 0 to 2 seemed to fix the issue. 1 degree still gave erratic results. The mount would sometimes flip, do a plate solve and flip straight back!! I would have gone further than 2 degrees, but I had mount clash issues at about 3 degrees.

I use plate solve2. This is generally reliable. Most meridian flip fails now are associated with the plate solve failing after the flip or coming up with crazy coordinates. Some of these are because the first plate taken after the flip starts before the mount has fully stabilized and the stars show some drift. The recovery mode usually fixes this as subsequent plates show no drift. An improvement would be a small delay (10s?) after the slew finished before the first plate.

I have noticed that the flip coordinates used by SGPro do not match the plate solve from prior to the flip. They have a small offset. I assume this is done on purpose to make sure the flip works. Irrespective, the mount moves to the correct coordinate in one or two iterations after the flip.

Hope this helps



When I was using SGP with my old NEQ6 almost all meridian flips failed because the telescope was quite a bit off after the meridian flip. With my new EQ8 (perfectly aligned and no cone error) I now have a better result. With the first clear night in a weekend I’m planning for a night of testing SGP doing flips because this is now the only thing that’s keeping me from shooting a whole night long with me sound asleep.



Regarding the time difference to Meridian flip. Eqmod calculates the time to Meridian. Sgpro calculates the time to the actual flip. So, if the flip is set 2 deg after Meridian, then sgpro will calculate flip as 8 minutes later than Eqmod.



Never had or have issues with meridian flip and center with eqmod (on the condition you do not build a model!!)

So I agree 100% with Scott,


From another thread.

Reply as linked Topic

Chris - If you mean V2.17l it was released in 2013. Its the latest version of EQASCOM on SourceForge. If you go on their Yahoo site they have released 15 versions since. The latest this October. They have made changes to pier side called “Pierside reporting swapped.” I don’t know why they all aren’t on SourceForge - maybe they are betas? Anyway, I was on 1.27l and had this problem. I switched to a later version 1.28g and haven’t had it since. However, I didn’t have the problem regularly so this may be a coincidence as weather has limited my recent imaging.

Reply as linked Topic

ChrisASCOM Developer2h
I’ve just joined their group, waited to be approved, and downloaded and installed the latest version 1.28k. I’m trying the simulator.

That one handles pointing state correctly as long as you select the SideOfPier option V1.24g. If the others are the same as in 1.27l.then they are all wrong.

Setting Physical is correct between hour angles 18 to 24/0 to 6 but fails with the unexpected pier flip at hour angles 6 and 18, this is what Jeroen is seeing.

This doesn’t seem to be something that should be user configured, the user is in an even worse situation than the developers when it comes to deciding which is correct.


So, it would seem that the latest version with Side of Pier Option V1.24g selected instead of Physical works all the time.


I’ve just read this too Tim and keen to know what to select as my pier side to ensure failsafe flipping in all positions.


As said by Tim “latest version with Side of Pier Option V1.24g selected” is the way to go, just done a series of tests and this combination gives consistent results.


“Latest version” is a trap, all it can ever mean is that it is the last version that you know of at the time that you posted.

In this case for people who go through the EQMOD front page to the Download link you get to the Sourceforge “Latest” version of 1.27l. There’s very little indication that there is another “latest” version in a restricted forum.

Always specify the version specifically.



Good point Chris. As Chris pointed out earlier he tested with 1.28k. A key thing to remember is that Eqmod does not keep their versions up to date on their Web page. You should join the Eqmod Yahoo group to get the latest updates.


The latest version mentioned above is version 1.28k, I have tested this as well as I can do indoors with a heq5 and it appears to work fine with the side of pier set to v1.24g instead of physical. Currently have no chance to check this with the weather we are having


Based on discussions above, tonight I trialed setting side of pier to “1.24g” instead of “physical”. Unfortunately, it does not work correctly with my setup on Eqmod 1.28b in the Southern Hemisphere. It causes meridian flips at odd times. As I have used “Physical” for several months with success, I will stick with it!




I was able to test this version and it works for me now!