Flip Calibration Data

Sequence Generator
1

Hello.

Last night’s meridian flip failed. Looking at the log file I could not tell if it was a post-flip centering problem that caused SGP to stop or if it was a guiding issue. The log file does state that calibration data was flipped. I seem to recall a calibration flip is only needed when ST4 guiding not when pulse guiding which is what I have been doing. It is the first time I am seeing that statement. I never press the Flip Calibration Date, and last night the flip was unattended.

The log file can be found here. I appreciate some insight into what could have happened.

Thanks

2

It looks like it failed due to a bad plate solve:

[08/27/20 00:28:44.153][DEBUG][Telescope Thread][SQ;MF;CE;] Auto center validation frame failed to solve. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.153][DEBUG][Telescope Thread][SQ;MF;CE;] Auto center validation frame solve failed. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.153][DEBUG][Main Thread][SQ;MF;CE;] Adding sequence level notification: Auto center validation frame solve failed. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.261][DEBUG][Telescope Thread][SQ;MF;CE;] Sending Notification: Error - Auto center validation frame solve failed. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.261][DEBUG][Telescope Thread][SQ;MF;CE;] Auto center failed! Auto center validation frame solve failed. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.268][DEBUG][Telescope Thread][SQ;MF;CE;] Close centering dialog...
[08/27/20 00:28:44.268][DEBUG][Telescope Thread][SQ;MF;] Center telescope message completed...
[08/27/20 00:28:44.268][DEBUG][Telescope Thread][SQ;MF;] Telescope thread is IDLE...
[08/27/20 00:28:44.555][DEBUG][Main Thread][SQ;MF;] Centering dialog is closed...
[08/27/20 00:28:44.555][DEBUG][Main Thread][SQ;MF;] Adding sequence level notification: Auto center failed! Auto center validation frame solve failed. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.642][DEBUG][Main Thread][SQ;MF;] Sending Notification: Error - Auto center failed! Auto center validation frame solve failed. Solve failed!  Maximum search limit exceeded.
[08/27/20 00:28:44.649][DEBUG][Pier Flip Thread][SQ;MF;] Something has gone wrong when centering after the meridian flip, but recovery mode is NOT active!
[08/27/20 00:28:44.652][DEBUG][Main Thread][SQ;MF;] Adding sequence level notification: Something has gone wrong when centering after the meridian flip, but recovery mode is NOT active!
[08/27/20 00:28:44.776][DEBUG][Pier Flip Thread][SQ;MF;] Sending Notification: Error - Something has gone wrong when centering after the meridian flip, but recovery mode is NOT active!
[08/27/20 00:29:14.554][DEBUG][Main Thread][SQ;] Adding sequence level notification: Failed to complete automatic meridian flip, aborting sequence!
[08/27/20 00:29:14.684][DEBUG][Sequence Thread][SQ;] Sending Notification: Error - Failed to complete automatic meridian flip, aborting sequence!
[08/27/20 00:29:14.903][DEBUG][Pier Flip Thread][SQ;] Meridian Flip: Procedure complete
[08/27/20 00:30:16.389][DEBUG][Sequence Thread][SQ;] Blocking Pier Flip: Failed to meridian flip, aborting sequence (True)
[08/27/20 00:30:16.390][DEBUG][Sequence Thread][SQ;] Aborting sequence: Failed to meridian flip

Jared

3

Thanks, Jared. What is it about flipping calibration data? Is it common for SGP to do that automatically after a flip?

4

Yes, you can see where it was also flipped in your log:

[08/26/20 23:29:14.740][DEBUG][Pier Flip Thread][SQ;MF;] Meridian Flip: Telescope command to meridian flip has completed
[08/26/20 23:29:14.745][DEBUG][Pier Flip Thread][SQ;MF;] Meridian Flip: Telescope has performed meridian flip
[08/26/20 23:29:14.745][DEBUG][Pier Flip Thread][SQ;MF;] Meridian Flip: Flipping Auto Guider calibration data

PHD2 also detects that the mount has flipped and will also handle this when connected via ASCOM.

Jared

5

So this is common then?

6

I’m not sure what you’re referring to as “this”? SGP did the “normal” stuff it always does to perform the flip…all of that was successful until your plate solve failed which is what caused the flip to fail.

Jared

7

By “this” I meant “flip calibration”. I should have been more clear.

8

Yes, SGP will always issue a “Flip Calibration Data” to PHD2 whenever a meridian flip occurs.

Jared

9

In PHD, flipping the cal data is also dependent on the guider optics. A straight through refractor is different to an off axis guider.
[update] I think this is not always the case. In my case, I was getting confused with the polarity change between Paramount DirectDrive and some other guiding interfaces.

10

Interesting. I have read their documentation and did not see that.

11

Yes, there are some options you may need to configure based on your guiding optical train inside of PHD2. These should be easy to test. Calibrate on one side…flip, see how the guiding goes after that. If everything is still on track do nothing. If dec goes off the rails toggle the option to not flip Dec. Also different mounts will automatically reverse Dec whenever you flip as well so there are a lot of options here.

If your mount is connected via ASCOM, PHD2 will automatically detect the flip and handle the calibration data flipping as well. You should never need to manually flip the calibration data in PHD2 if your mount is connected via ASCOM…and doing so would likely cause your guiding to be messed up at least in Dec.

Jared

12

Jared, that is what I thought too: ASCOM mount and not needing to manually flip. The reason I was asking is because I noticed it the first time I was looking at the log. Also if PHD2 automatically does it, and SGP also does it, would they not cancel each other out?

I have not had any issues with this to date. Just wondering.

Thanks

13

No, PHD2 recognizes this when connected via ASCOM and will silently prevent the cal data flip from SGP. If just connected via ST4 then PHD2 will flip the calibration data as SGP requests whenever it requests it.

Jared

14

Good to know. Thanks.