Slewing and sync

Questions and answers about the best way to get started with Prism including: est hardware to use, software settings, etc..
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Posts: 11
Joined: Fri Apr 19, 2019 3:54 pm

Sun Apr 21, 2019 7:05 pm

I’m new to prism, I have the pro version. Some background. I have a paramount Myt, Celestron 8 Edge HD (using an attached moonlight focuser) and a Stellavue 130 refractor, QSI 683 wsg, Primalucelab Eagle 2 pro, and Sesto Senso.
I use SkyX to polar align and run Tpoint and turn on pro track.
I have successfully connected to all my equipment. My question is when I slew to a target does prism also do a sync. If so, will this mess up my tpoint. In the ASCOM settings for the mount I check “ Inhibit Sync to protect Tpoint”. Will this prohibit any sync in prism. I also use SGP and sync must be turned off.
I have not used prism to do any imaging yet, still learning how to set all parameters, watching videos and reading manual..
Are there any other concerns I might encounter using the paramount. I did learn from the forum to have SkyX running in the background.
Posts: 128
Joined: Thu Aug 23, 2018 8:22 pm
Location: Missouri, USA

Tue Apr 23, 2019 1:50 pm

Ed, I can't really say with 100% certainty as I'm still learning Prism and I find out more and more everyday that I did not know about this hobby.

I'm using an Orion Atlas mount via EQmod. The behavior appears to be that if you command a slew there is no sync sent. If I then take an image and platesolve it I'm prompted saying something like "do you want to sync the telescope position to this?" yes sends a sync (I've never clicked no). There is a right click command in prism called "sync telescope to here" or words to that effect, I am not sure if that means "center here and sync" like other programs or not.

I decided today that I need to setup the ASCOM simulators and do a few more tests in prism.

I am not familiar with Tpoint, but I used to be an SGP user myself. In SGP I notice the same behavior, if SGP platesolved a sync would be sent but not on just a slew command.

I assume that both applications would be sending the sync via ASCOM so if your mounts driver has a way to block them then that should be "below" the layer of SGP or Prism and thus be prevented from getting to the mount.

To be on the safe side you may want to setup a simulator if available to do some testing. I believe that there is a specific checkbox buried in the settings I remember seeing something about check this box if you have a micron mount or wording like that.

Hope that helps somehow, I'm sure someone with more knowledge and experience will come along shortly.
Posts: 11
Joined: Fri Apr 19, 2019 3:54 pm

Tue Apr 23, 2019 4:07 pm

Thank you for the reply. I agree slewing does not do a sync. Where sync might be applied is after an automatic function. For example, after a meridian flip which would need to be plate solved. Also on an automatic run. Scope slew to first target, plate solve and sync to center target. Focus, etc.
The ASCOM driver for SB paramount allows you to inhibit any sync to protect the Tpoint model for the paramount mount. My concern is when prism tries to perform a sync it will throw up its hands and fail. This is all theory because I have not tried it because weather has not cooperated. Until I can get outside and test, I hoped others on the forum might have some input. I am sure there are a Prism users using SB paramount mounts or Hamza could share some insight.
I know using SGP this was a major problem for paramount users. It was finally resolved by the programmers putting in another option called offset target. I am not quite sure how that works, but suspect when plate solve is done, the mount centers the target from where the scope is pointing to the actual ra and dec coordinate without a sync.
With an excellent PA and tpoint model all my targets are dead center always without ever syncing.
Hamza Touhami
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Posts: 564
Joined: Sat May 20, 2017 6:05 pm
Location: Phoenix,AZ

Wed Apr 24, 2019 12:20 pm

remember that PRISM is a software, the driver decides whether to accept a sync, reject it or whatever else. in the case of Paramounts, theSkyX ASCOM driver is where you to choose to now allow sync, as an example.
Hamza Touhami | Site Administrator
Posts: 11
Joined: Fri Apr 19, 2019 3:54 pm

Wed Apr 24, 2019 2:55 pm

Thanks, Hamza.
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