Meridian Flip Fail - Log Snippet attached


I have been using SGP for about three years and have never had a problem with meridian flips. The last three nights I’ve been having problems.

I watched the imaging closely last night. I was taking 10 minute subs. When sub 13 was saved there were 8 minutes remaining until the meridian flip was scheduled. No flip occurred and Sub 14 started. Unfortunately, PHD2 thought it was now on the west side and ran away from the guide star. SPG parked the telescope. Here is a snippet of the log starting with the successful save of sub 13. I have also attacxhed a picture of my “flip” options.

Any help would be appreciated.


SGP_Snippet.txt (43.9 KB)



What are your settings on the Telescope tab of the control panel? That is where the flip is set up. What you are showing just causes a center after the flip (if any).


I think you should also check the box “Wait For Meridian” (Can’t check mine just now - sorry).


Thanks for responding:

Should “reverse Dec output after meridian flip” be checked? I didn’t have it checked.


Well, the flip didn’t happen because you told it not to.

  • Wait For Meridian is unchecked. This means if the mount isn’t to the time to flip, SGP will start the next frame…regardless of how soon the flip comes. If this is checked, then if “time before flip” < “exposure time of image”, SGP will wait for the flip, perform it, and then start imaging again. Since you state “8 minutes remaining until the meridian flip was scheduled”…SGP started the next frame.
  • Minutes Past Meridian to Flip is 8. Line 56 of your log shows this point had not been reached.

PHD appears to have “run away from the guide star” during a dither settle…not sure why that happened. I don’t THINK SGP ever tells PHD (or should have to) anything about “Scope is on this side”…that should, if memory serves, be the mount driver’s job, if anyone’s. Your log snippet suggests the same thing…doesn’t appear to be any signal form SGP that PHD should be doing anything different, or that mount side of pier has changed.

Frankly, I have a hunch that SGP not flipping is a bit of a red herring…true, it didn’t flip…but it had been told not to yet. So, it appears to have been cruising along quite happy, well aware of where everything was and what it was doing.

PHD log for that time period might prove helpful, to see if perhaps the mount driver told it something erroneous?

As for whether the Reverse Dec box should be checked…hard to say, since you don’t say what mount you’re using. That setting’s pretty mount-dependent ime.


Thank you for your “indepth” response. I think you’ve got me straigthen out. I’ll find out tonight!


Good luck!