Odd behaviour Meridian flip and dome slaving

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Set-up:

  • SGP
  • Mesu 200 mount via “SiTech-II telescope” in equipment profile
  • UNIWERSAL dome via “LesveDomeNet” in equipment profile

Last night I was imaging M42.
As time for an Automatic Meridian Flip was nearing, I got a dialog box saying that the next frame was too long and that there were 17 seconds remaining before the meridian.

I overrode the count-down (–possibly should not have–) and told SGP to flip in the dialogue box. (I can’t find the dialogue box in the documentation, so I don’t recall the precise wording.)

The mount did not move (!), but the dome slewed.
The Auto MF process started to platesolve: the platesolve failed, probably because the dome had moved, but not the scope. The camera had taken a picture of the dome wall.

Equipment profile is set to Auto MF.

  • Auto MF is set to “Wait for Meridian” and “Auto-center after MF”.
  • Minutes past horizon: 0.
  • Auto MF auto-close delay: 30

Could anyone tell me what I may have done wrong for the scope not to move upon Auto MF?

Thank you,
Kris

2

On many scopes, SGP does a flip by sending a slew command to the scope. In that case, if the scope thinks it is before the meridian, no flip will happen. It’s best to wait until a few minutes after the meridian before attempting a flip because the meridian time in SGP and the scope may not precisely agree.

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Thank you, DesertSky,

for your useful input.

I’ll adjust my settings to flip a few minutes post-meridian.

I’ll play around with this when I return to my observatory in March…

Are you using the same set-up by any chance?

Any suggestions on whether it is preferable in SGP to use POTH twice (for scope and dome) rather than a direct connection to SiTech II and LesveDomeNet?

Best regards,
Kris

Kris:

The mount did not move

On many scopes, SGP does a flip by sending a slew command to the scope. In that case, if the scope thinks it is before the meridian, no flip will happen. It’s best to wait until a few minutes after the meridian before attempting a flip because the meridian time in SGP and the scope may not precisely agree.

4

I don’t have any experience with domes but based on other responses I have seen I think you want to have SGP control the scope and the dome directly without POTH.