Auto meridian flips with SGP


Peter Bresler
 

i finally had a successful autoflip with the settings suggested. PHD2 on in SGP, and SGP recovery if the guide star is lost.


Tom Zepf
 

On Tue, Nov 9, 2021 at 07:51 AM, Ray Gralak wrote:

Hi Tom,

 

Of course, APCC will do that using the settings shown in your screenshots. You have not set non-zero values for "Flip Offset" and "Flip Offset Padding".

OK, I misunderstood the UI. I saw the checkbox for "Limit to Meridian" above the "Flip Offset" and "Flip Offset Padding" and assumed it needed to be checked for those values to take effect. But then it would not have achieved what I wanted, so I didn't adjust the values. I now see they are disconnected and just happen to be (nearly) lined up vertically. Good grief, sorry!

 Flip Offset essentially moves the flip point sent to SGPro, so that SGPro has time to complete an image before the mount reaches the actual meridian limit. Typically you want to set the Flip Offset to the maximum duration of the image, plus a couple of extra minutes.


Ah, this language would be very helpful in the help file! I read the help file a dozen times, but had a hard time understanding what it was trying to say for "Flip Offset" and "Send Limit to SGPro".

Perhaps also something to the effect of "Minutes Past Meridian to Flip will be adjusted in SGPro Meridian Flip Options" might also help in the wording for "Send Limits to SGPro". After I finally figured out that was the value being adjusted, it all made much more sense.
 
 

 Maybe it would help if you took a look at the help page for Meridian Limits. You can click the "?" icon in the upper right corner of the "Operations" group box, as shown in this screenshot (info has not been added for “Flip Padding” yet):


Believe me, I did, but somehow it did not make sense to me. Probably something to do with "The Fog of Astrophotography" and not enough sleep and a frozen brain. It makes sense to me now, thanks for the help!

    Tom


Ray Gralak
 

Hi Tom,

 

You wrote:

> 1.      APCC adjusts the Meridian Flip settings in SGPRo erasing any delay or fudge factor that might have

> been in the SGPro settings before. See Showing-SGPro-Adjusted-Meridian-Flip-Options.png for details.

> 2.      If Guiding is still going on, APCC halts Tracking before SGPro gets a chance to flip, so PHD2 throws

> an error, the sequence stops, and end of sequence steps are initiated before SGPro gets a chance to flip.

 

Of course, APCC will do that using the settings shown in your screenshots. You have not set non-zero values for "Flip Offset" and "Flip Offset Padding".

 

Flip Offset essentially moves the flip point sent to SGPro, so that SGPro has time to complete an image before the mount reaches the actual meridian limit. Typically you want to set the Flip Offset to the maximum duration of the image, plus a couple of extra minutes.

 

Flip Offset Padding is a new control added in the beta. It adds or subtracts a little extra time to account for any time discrepancy between SGPro and the mount. Note the value is in minutes and can be positive or negative.

 

> Ray, have you tried this with the latest Beta and SGPro and gotten it to work? If so, I'd love to see your

> settings so I could give it a try. :-)

 

Maybe it would help if you took a look at the help page for Meridian Limits. You can click the "?" icon in the upper right corner of the "Operations" group box, as shown in this screenshot (info has not been added for “Flip Padding” yet):

 

 

-Ray

 

> -----Original Message-----

> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Tom Zepf

> Sent: Monday, November 8, 2021 7:53 PM

> To: main@ap-gto.groups.io

> Subject: Re: [ap-gto] Auto meridian flips with SGP

>

> On Mon, Nov 8, 2021 at 08:46 AM, Ray Gralak wrote:

>

>

>          Hi Tom,

>

>

>

>                      I tried the latest Beta and I still had the same race condition issues, but there's a good chance I

> just didn't

>                      configure things. correctly.

>

>          Exactly, what configuration settings did you use? I can't correct or promote the software to a release

> version without logs and settings information. Just saying it didn't work is not going to help! :-)

>

>          Thanks,

>

>          -Ray

>

> I've zipped up log files and screen shots showing the configuration settings. You can find them here:

> https://drive.google.com/file/d/11LqdWemaDSeLpSZoXX9wO3QtOzNQLTcY/view?usp=sharing

>

> From what I can tell, if you have APCC send the limits to SGPro, it basically runs things right up to the wire,

> and SGPro shows a flip time that is within seconds of what APCC thinks is the limit where it will stop tracking.

> I made these logs with Simulation gear (bad weather for a few days ahead), but with real gear, what seems to

> happen is something like this:

>

>

> 1.      APCC adjusts the Meridian Flip settings in SGPRo erasing any delay or fudge factor that might have

> been in the SGPro settings before. See Showing-SGPro-Adjusted-Meridian-Flip-Options.png for details.

> 2.      If Guiding is still going on, APCC halts Tracking before SGPro gets a chance to flip, so PHD2 throws

> an error, the sequence stops, and end of sequence steps are initiated before SGPro gets a chance to flip.

>

> What I have, is a way to make this work with "shallow" hard-wired "flip within a degree or two of the meridian at

> all declinations". See the settings earlier in the thread for that. But I don't get the "deep" counterweight up flips

> that would be nice.

>

> What I think I need, is a configuration that allows for the travel into the counterweight up position if declination

> and meridian limits allow it, but I cannot figure out how to do that with the knobs I've tried turning.

>

> Ray, have you tried this with the latest Beta and SGPro and gotten it to work? If so, I'd love to see your

> settings so I could give it a try. :-)

>

> Thanks,

>

>     Tom


Luca Marinelli
 

Hi Tom,

I am traveling right and cannot post screenshots but I have no problem with automated meridian flips with APCC 1.9 and SGP V4.680 on both an AP1100 and Mach2 with APCC sending limit to SGP with the appropriate flip offset for the length of my exposures.

I have posted screenshots of APCC meridian limit configuration and SGP meridian flip window and if you search posts under my name they shouldn’t be hard to find. 

If everything is setup appropriately you should see the flip time in SGP change when you modify the flip offset in APCC. 

Best,

Luca 

On Nov 8, 2021, at 7:53 PM, Tom Zepf via groups.io <tjzcos@...> wrote:

On Mon, Nov 8, 2021 at 08:46 AM, Ray Gralak wrote:
Hi Tom,

I tried the latest Beta and I still had the same race condition issues, but there's a good chance I just didn't
configure things. correctly.
Exactly, what configuration settings did you use? I can't correct or promote the software to a release version without logs and settings information. Just saying it didn't work is not going to help! :-)

Thanks,

-Ray 
I've zipped up log files and screen shots showing the configuration settings. You can find them here: https://drive.google.com/file/d/11LqdWemaDSeLpSZoXX9wO3QtOzNQLTcY/view?usp=sharing

From what I can tell, if you have APCC send the limits to SGPro, it basically runs things right up to the wire, and SGPro shows a flip time that is within seconds of what APCC thinks is the limit where it will stop tracking. I made these logs with Simulation gear (bad weather for a few days ahead), but with real gear, what seems to happen is something like this:
  1. APCC adjusts the Meridian Flip settings in SGPRo erasing any delay or fudge factor that might have been in the SGPro settings before. See Showing-SGPro-Adjusted-Meridian-Flip-Options.png for details.
  2. If Guiding is still going on, APCC halts Tracking before SGPro gets a chance to flip, so PHD2 throws an error, the sequence stops, and end of sequence steps are initiated before SGPro gets a chance to flip.
What I have, is a way to make this work with "shallow" hard-wired "flip within a degree or two of the meridian at all declinations". See the settings earlier in the thread for that. But I don't get the "deep" counterweight up flips that would be nice.

What I think I need, is a configuration that allows for the travel into the counterweight up position if declination and meridian limits allow it, but I cannot figure out how to do that with the knobs I've tried turning.

Ray, have you tried this with the latest Beta and SGPro and gotten it to work? If so, I'd love to see your settings so I could give it a try. :-)

Thanks,

    Tom


Tom Zepf
 

On Mon, Nov 8, 2021 at 08:46 AM, Ray Gralak wrote:
Hi Tom,

I tried the latest Beta and I still had the same race condition issues, but there's a good chance I just didn't
configure things. correctly.
Exactly, what configuration settings did you use? I can't correct or promote the software to a release version without logs and settings information. Just saying it didn't work is not going to help! :-)

Thanks,

-Ray 
I've zipped up log files and screen shots showing the configuration settings. You can find them here: https://drive.google.com/file/d/11LqdWemaDSeLpSZoXX9wO3QtOzNQLTcY/view?usp=sharing

From what I can tell, if you have APCC send the limits to SGPro, it basically runs things right up to the wire, and SGPro shows a flip time that is within seconds of what APCC thinks is the limit where it will stop tracking. I made these logs with Simulation gear (bad weather for a few days ahead), but with real gear, what seems to happen is something like this:
  1. APCC adjusts the Meridian Flip settings in SGPRo erasing any delay or fudge factor that might have been in the SGPro settings before. See Showing-SGPro-Adjusted-Meridian-Flip-Options.png for details.
  2. If Guiding is still going on, APCC halts Tracking before SGPro gets a chance to flip, so PHD2 throws an error, the sequence stops, and end of sequence steps are initiated before SGPro gets a chance to flip.
What I have, is a way to make this work with "shallow" hard-wired "flip within a degree or two of the meridian at all declinations". See the settings earlier in the thread for that. But I don't get the "deep" counterweight up flips that would be nice.

What I think I need, is a configuration that allows for the travel into the counterweight up position if declination and meridian limits allow it, but I cannot figure out how to do that with the knobs I've tried turning.

Ray, have you tried this with the latest Beta and SGPro and gotten it to work? If so, I'd love to see your settings so I could give it a try. :-)

Thanks,

    Tom


Ray Gralak
 

Hi Tom,

I tried the latest Beta and I still had the same race condition issues, but there's a good chance I just didn't
configure things. correctly.
Exactly, what configuration settings did you use? I can't correct or promote the software to a release version without logs and settings information. Just saying it didn't work is not going to help! :-)

Thanks,

-Ray


Peter Bresler
 

Thanks for the info.....I will  try to set it up.


Tom Zepf
 
Edited

On Sun, Nov 7, 2021 at 12:02 PM, Marcelo Figueroa wrote:
The latest beta version of APCC allows to set a time window for the flip so that SGP can run it without conflict between the two. Personally I have not tested it, I am waiting for the final version (not beta).
 
In the meantime I simply disable the meridian limits option in APCC and let SGP do it all on its own, it works perfect.
I tried the latest Beta and I still had the same race condition issues, but there's a good chance I just didn't configure things correctly.

I didn't want to run without a fail-safe tracking stop enforced by the mount (APCC) - I like to have two sets of controls for things that can damage my equipment, so I've gone this route. I setup my iOptron mount the same way - the mount fail-safe stopped at 2 degrees, but I had SGP flip at 1 degree past the meridian. I'm probably just paranoid, that's all!


Marcelo Figueroa
 

The latest beta version of APCC allows to set a time window for the flip so that SGP can run it without conflict between the two. Personally I have not tested it, I am waiting for the final version (not beta).
 
In the meantime I simply disable the meridian limits option in APCC and let SGP do it all on its own, it works perfect.


Tom Zepf
 
Edited

I have struggled with this a great deal as well. This may not the best configuration for your circumstance, but the following screenshots of APCC and SGPro settings work reliably for me now.

I could be off-base, but I believe *not* checking the box to send updates to SGPro and allowing counterweight up slews were what finally got this working. There seems to be some sort of race condition I could never work around.

In my case, I am using a meridian limits file I tweaked in an editor to just be a simple 2 degree limit east and west, but this should work with any set of limits. Be aware, if you aren't, that SGPro cannot do a meridian flip "underneath" the pole. But this configuration is rare and will cause the scope to stop tracking in that case, so it should fail safe.

I did spend a great deal of time using the very useful ASCOM Sky Simulator to debug this in daylight hours. https://sourceforge.net/projects/sky-simulator/

Now, because I'm a glutton for punishment, I'm working on replicating my workflow in N.I.N.A. which seems much more flexible, speedy, and has developers actively working on it.

Good luck and clear skies!

   Tom











Peter Bresler
 

I have yet to program a successful auto meridian flip with SGP. Should APCC meridian be set to execute a flip? What should the telescope settings in SGP be? An ancillary problem is that if PHD2 guiding is set in SGP, and the guide star is lost, the sequence aborts.