Date   

Re: Lost communications with mount

weihaowang
 

Hi Deonb,

Thank you.  Unfortunately I don't have a Mac with bootcamp enabled.  About 8, or 9 years ago, I started with
bootcamp for telescope control.  Then I found it very unstable.  Surprisingly, with the same Windows installation,
once the bootcamp partition was converted to Parallels VM, it worked very nicely.  Since then, I just stick to
Parallels for telescope control.  So far, it works quite well for controlling various cameras and iOptron and TAK 
mounts.  So I doubt it is a VM related issue, but this is nevertheless a possibility.  I just don't know how to 
verify this.





--

Homepage:

http://www.asiaa.sinica.edu.tw/~whwang/

Astrobin gallery:
http://www.astrobin.com/users/whwang/


Re: Lost communications with mount

deonb
 

George, he's running a Windows 7 virtual machine on the MAC (so I assume he's running Windows 7 in something like Parallels).

So it will still use an ASCOM driver, but using an emulated USB port from the VM.

Wei-Hao do you have an option to do a test inside bootcamp?


Re: Lost communications with mount

George
 

Wei-Hao,

 

If you are using a Mac, then you are not connecting to ASCOM (ASCOM is Windows only).    You are using Sky native drivers.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of weihaowang
Sent: Wednesday, December 30, 2020 12:57 AM
To: main@ap-gto.groups.io
Subject: [ap-gto] Lost communications with mount

 

Hi,

I am doing table-top testing of our Mach2 (before we can put it on a proper tripod).  I use TheSky6 in a Windows 7 virtual machine on my Mac.  GTOCPS5 is connected to the computer with a short USB2.0 cable and converted to USB-C to the Mac.  Under TheSky6, I connect to Mach2 with ASCOM V2 Driver.  The ASCOM driver sometimes connects to Mach2 by itself, sometimes through a virtual port under APCC Pro.  Either way, the behavior doesn't change.  Using different cables doesn't solve the problem either.

What I do is just do a very small slew near north pole under TheSky, and let the mount track.  Almost always, within just a few minutes, TheSky shows an error message saying "Lost communications with mount."  At almost the same time, the mount makes a very tiny sound, which sounds like it parks itself.  I suppose this is not something I want to see during a real observation/imaging session.

This is my first time using an Astro-Physics mount.  So I may have done something wrong.  Please let me know what I can do to solve this, or what I can provide for diagnosis.

Cheers,
Wei-Hao


 

--

Homepage:

http://www.asiaa.sinica.edu.tw/~whwang/

Astrobin gallery:
http://www.astrobin.com/users/whwang/


Re: Connecting to ASCOM generates new ASCOM window. #ASCOM_V2_Driver

George
 

Michael,

 

Contact me and I can check over your settings.   Have your astro computer with you.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Micheal Fields Jr via groups.io
Sent: Tuesday, December 29, 2020 11:49 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] Connecting to ASCOM generates new ASCOM window. #ASCOM_V2_Driver

 

I was using the most recent release of APCC Pro and the same thing was happening.  I updated to .11 today and the same thing remains.

Not sure if there is a new ASCOM V2 driver but I'll go look.

Anyways, I connect to the mount via ASCOM and it pops up the ASCOM window for each connection.
N.I.N.A generates one, PHD2 guiding generates another.  

Not 100% sure what I am doing wrong but I am sure it is just a setting somewhere.   What am I doing wrong?


Re: Should Mach1 users follow the APCC Pro upgrades? #APCC

Ron Kramer
 

Uninstall sgp. Install Nina.   Be done with being wary. Seriously.  And it’s free and will reside alongside sgp for a while as you test it. If sgp was good there would have been no reason for Nina.  I used sgp for two years not because it was good but because it usually worked.   Now Nina works and is 👍 

On Tue, Dec 22, 2020 at 8:05 PM Ray Gralak <groups3@...> wrote:
> The only problems I have with my current versions is that sometimes the WiFi stops working (a known problem I
> believe) and sometimes, at random, APCC loses it's USB connection to the mount and the mount stops tracking. Are
> either of these problems addressed in the upgrades?

Neither of these two issues is an issue with APCC. If you are having USB problems, it is likely being caused by a bad cable, a problematic USB hub, if you are using one, or the USB driver or USB device on your computer.

That being said, you should always update to the latest version (currently APCC Pro v1.8.8.9, or APCC Standard v1.8.8.0). If there are any issues you can always reinstall the version you had installed previously. You can even recover previous settings from APCC's  Backups folder.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

> -----Original Message-----
> From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Nick Iversen
> Sent: Monday, December 21, 2020 3:25 PM
> To: main@ap-gto.groups.io
> Subject: [ap-gto] Should Mach1 users follow the APCC Pro upgrades? #APCC
>
> I'm a bit wary of all these updates to mount firmware and APCC Pro because I see them as mainly for Mach2 users.
> I'm on P01 firmware and APCC Pro 1.7.1.5 and WiFi 04 and I'm scared of going to P02 and 1.8 in case I lose, say, the
> ability for Sequence Generator Pro to do a meridian flip.
>
> Essentially - what is new and what are the advantages of the upgrades?
>
> The only problems I have with my current versions is that sometimes the WiFi stops working (a known problem I
> believe) and sometimes, at random, APCC loses it's USB connection to the mount and the mount stops tracking. Are
> either of these problems addressed in the upgrades?
>







Re: Changing polar alignment...Ground shifting?

deonb
 

+1 for the advice on Pier Engineering. It worked out well, I can kick/pound my pier as hard as I can and at 2800mm FL have no visible vibrations transfer onto the scope.

I don't even have that big of a pier - I wanted to make sure it's not too heavy to lift back out again with my tractor. It's 18" wide below ground (3.5' deep)  and 8" wide above ground so comes in just around 1070lbs (920 lbs below ground, 150 lbs above). But because the concrete pour has been allowed to follow the contour of the compacted soil (Pier Engineering thread), it's held firmly in place. It's a good principle.

I built it in 2 stages with the below ground stage poured first and rebar sticking up out of it. I then embedded a piece of wooden "dovetail" across the top of the wet concrete, waited 2 weeks, chiseled out the wooden dovetail again, then poured the narrow sonotube part around the rebar and into the dovetail slot. Just make sure your rebar placement doesn't interfere with where you want the L-bolts of the pier plate to go (North aligned generally).

It's been rock solid since I poured it, until this week. It would hold polar alignment perfectly for weeks, and then suddenly the next day it's off by 15'. Fix it, then again, next day off by 15' again. Couldn't figure it out until my wife mentioned that the news was reporting earthquakes this week, and the days lined up perfectly. Was concerned there since the timing also aligned with when I put on the Mach2GTO, so I was quite thankful to hear about the quakes!

Oh well, that's why it's important to have a bolted design like Dan's Pier Plates that you can just re-level. Couple of turns with the wrench and the top plate is back to level.


Re: Changing polar alignment...Ground shifting?

Phillip H Coker <pcoker36@...>
 

I drilled three 1" holes 15 Inches into the base spaced to match the slots in the flange at the bottom of the 10" diameter steel pier. I epoxied three threaded 1" x 18" steel bars into the holes which left about three inches protruding above the base. With nuts and washers on the bars beneath and above the flange, it was very easy to adjust the pier to be perfectly vertical and it never moved in the five years I used it. The base was not concrete however. I lived on the side of Cheyenne Mountain in Colorado Springs at the time and had my observatory sitting over a megaton boulder.
Phil

On Dec 30, 2020, at 00:30, Dale Ghent <daleg@elemental.org> wrote:


Ouch. If you really want to know if it's your pier then you can get a digital inclinometer and periodically measure the pier on two axes to get an idea as to what's going on.

I'm going to auger out and pour a pier footer in the upcoming spring and I've been taking heavy notes from a good thread on the CN observatory forum called "Pier Engineering":

https://www.cloudynights.com/topic/652025-pier-engineering/

The basic takeaways are from the author's experiences are:

1. Auger, don't dig out, the hole for the pier, and remove all loose material from the side wall and bottom
2. Pour the footer into the hole, using the hole itself as the form. You can use a sonotube form or whatever for the top several inches to give it a finished aesthetic above ground, but for the majority of it you want direct contact with the surrounding compacted soil.
3. Mind your frostline
4. A bunch of other things that should be considered aside from basic hole digging and concrete pouring

The reasoning is that you'll have concrete directly in contact with the existing undisturbed and compacted soil instead of loose fill. There is also no sonotube that will ultimately decay and leave voids between the footer and the surrounding soil. These voids invite shifting, and the lack of loose fill surrounding the pier means that it will be better supported and more stable.

I'm no soil engineer but it makes sense and, in my case, I really have to nail it on the first try because the place where I want to put a pier is the only location in my yard that I get the most sky... so a do-over would mean a less ideal location, even if it's just a few feet to the side.

Hope the cause of your tilting has an easy solution.
/dale

On Dec 29, 2020, at 22:04, Tom Blahovici <tom.va2fsq@videotron.ca> wrote:

Hi
I thought I would ask the experts here about my shifting polar alignment.
5 years ago I rented a backhoe, and dug a hole 7 feet deep in my backyard. I then poured a concrete pillar in a form 3'x3' by 6 feet deep. On this I have a paramount pier.
All the earth was filled in and I have used this mostly over the winter. Last year all was fine. This year I had about 1 minute of arc drift in each axis using pempro.
Recently I started noticing that my stars appeared trailed during long exposures and autoguiding was acting up. PHD 2 told me my polar alignment was off by 4 degrees. . So today I checked my polar alignment with pempro and sure enough, 4-6 degrees off in drift. I have put it back to within 1 minute.
I thought I was golden with such a pier. Recently we had a lot of rain and then the temperatures have been going between + 12C and -12C. Could this be a factor? How often do you check your alignment?
Thanks


Re: Changing polar alignment...Ground shifting?

Dale Ghent
 

Ouch. If you really want to know if it's your pier then you can get a digital inclinometer and periodically measure the pier on two axes to get an idea as to what's going on.

I'm going to auger out and pour a pier footer in the upcoming spring and I've been taking heavy notes from a good thread on the CN observatory forum called "Pier Engineering":

https://www.cloudynights.com/topic/652025-pier-engineering/

The basic takeaways are from the author's experiences are:

1. Auger, don't dig out, the hole for the pier, and remove all loose material from the side wall and bottom
2. Pour the footer into the hole, using the hole itself as the form. You can use a sonotube form or whatever for the top several inches to give it a finished aesthetic above ground, but for the majority of it you want direct contact with the surrounding compacted soil.
3. Mind your frostline
4. A bunch of other things that should be considered aside from basic hole digging and concrete pouring

The reasoning is that you'll have concrete directly in contact with the existing undisturbed and compacted soil instead of loose fill. There is also no sonotube that will ultimately decay and leave voids between the footer and the surrounding soil. These voids invite shifting, and the lack of loose fill surrounding the pier means that it will be better supported and more stable.

I'm no soil engineer but it makes sense and, in my case, I really have to nail it on the first try because the place where I want to put a pier is the only location in my yard that I get the most sky... so a do-over would mean a less ideal location, even if it's just a few feet to the side.

Hope the cause of your tilting has an easy solution.
/dale

On Dec 29, 2020, at 22:04, Tom Blahovici <tom.va2fsq@videotron.ca> wrote:

Hi
I thought I would ask the experts here about my shifting polar alignment.
5 years ago I rented a backhoe, and dug a hole 7 feet deep in my backyard. I then poured a concrete pillar in a form 3'x3' by 6 feet deep. On this I have a paramount pier.
All the earth was filled in and I have used this mostly over the winter. Last year all was fine. This year I had about 1 minute of arc drift in each axis using pempro.
Recently I started noticing that my stars appeared trailed during long exposures and autoguiding was acting up. PHD 2 told me my polar alignment was off by 4 degrees. . So today I checked my polar alignment with pempro and sure enough, 4-6 degrees off in drift. I have put it back to within 1 minute.
I thought I was golden with such a pier. Recently we had a lot of rain and then the temperatures have been going between + 12C and -12C. Could this be a factor? How often do you check your alignment?
Thanks


Lost communications with mount

weihaowang
 

Hi,

I am doing table-top testing of our Mach2 (before we can put it on a proper tripod).  I use TheSky6 in a Windows 7 virtual machine on my Mac.  GTOCPS5 is connected to the computer with a short USB2.0 cable and converted to USB-C to the Mac.  Under TheSky6, I connect to Mach2 with ASCOM V2 Driver.  The ASCOM driver sometimes connects to Mach2 by itself, sometimes through a virtual port under APCC Pro.  Either way, the behavior doesn't change.  Using different cables doesn't solve the problem either.

What I do is just do a very small slew near north pole under TheSky, and let the mount track.  Almost always, within just a few minutes, TheSky shows an error message saying "Lost communications with mount."  At almost the same time, the mount makes a very tiny sound, which sounds like it parks itself.  I suppose this is not something I want to see during a real observation/imaging session.

This is my first time using an Astro-Physics mount.  So I may have done something wrong.  Please let me know what I can do to solve this, or what I can provide for diagnosis.

Cheers,
Wei-Hao


 

--

Homepage:

http://www.asiaa.sinica.edu.tw/~whwang/

Astrobin gallery:
http://www.astrobin.com/users/whwang/


Connecting to ASCOM generates new ASCOM window. #ASCOM_V2_Driver

Micheal Fields Jr
 
Edited

I was using the most recent release of APCC Pro and the same thing was happening.  I updated to .11 today and the same thing remains.

Not sure if there is a new ASCOM V2 driver but I'll go look.

Anyways, I connect to the mount via ASCOM and it pops up the ASCOM window for each connection.
N.I.N.A generates one, PHD2 guiding generates another.  

Not 100% sure what I am doing wrong but I am sure it is just a setting somewhere.   What am I doing wrong?

Ok I deleted all virtual com ports and removed the traces and then unchecked auto start and auto config.  This seems to be working fine now.  Only one ascom interface popped up.


Re: Changing polar alignment...Ground shifting?

Woody Schlom
 

Tom,

 

There are places where the ground swells and shrinks over the year depending on moisture content and/or freezing.

 

Freezing ground with lots of moisture in it causes swelling.  I think it’s called frost swell – or something like that.

 

Another ground condition that causes seasonal rising and falling is a high clay content.  Apparently clay swells when it’s wet and shrinks when it dries.

 

Huston, TX is famous for seasonal ground rising and falling due to moisture content.  I understand the ground in Huston can rise and then fall at least a FOOT depending on moisture content.  And this goes for buildings, parking lots, and single-dwelling houses.  And weight means nothing.  If the ground wants to swell and rise – 100,000 lbs. of concrete is nothing.

 

And here in Southern California we have earth quakes – which moves the ground up, down, and even sideways.  After a really big quake, some of the guys in my club with permanent piers have to re-adjust P.A.

 

So there are several possible causes of PA changing.

Woody


Re: Changing polar alignment...Ground shifting?

deonb
 

I think he might be from Anacortes (if he's the same Tom as from Astromart).

If so, Tom, you had an earthquake the day before yesterday:
https://pnsn.org/event/61707166#overview


Re: Changing polar alignment...Ground shifting?

M Hambrick
 

Do you live in an area where the water table is close to the surface, or where the bedrock is far below (e.g. Texas Gulf coast) ?


Re: Changing polar alignment...Ground shifting?

Mike Dodd
 

On 12/29/2020 10:10 PM, deonb wrote:
4-6 */degrees/* of drift? (Not minutes?).
That's what I was going to ask. If it's off by that much, you should be able to put a level up against the pier (or just look at it) to check if it is still plumb.

It seems unlikely that rain could have shifted a 3x3x6 concrete block that much. That's 8,100 pounds of concrete -- a huge mass!

Was there an earthquake in your area by chance?
That would be the only thing that would move such a mass. Where are you located?

I've built two concrete piers without any super-duper footers. The most recent is 12" in diameter, rising about 66" above the ground, and sunk about 40" in the ground with a 24" "blob" of concrete at the bottom for a footer. I used a power earth auger to dig the hole, then hollowed-out the bottom for the "blob" footer. Definitely nothing special about this pier, but it hasn't moved in four years. It DOES have an observatory around it, so it's sheltered from rain.

Tell us more, please!

--- Mike


Re: Changing polar alignment...Ground shifting?

deonb
 

4-6 degrees of drift? (Not minutes?).  

Was there an earthquake in your area by chance? We had a few over the last week, and my polar alignment has been all over the place.


Changing polar alignment...Ground shifting?

Tom Blahovici
 

Hi
I thought I would ask the experts here about my shifting polar alignment.
5 years ago I rented a backhoe, and dug a hole 7 feet deep in my backyard.  I then poured a concrete pillar in a form 3'x3' by 6 feet deep.  On this I have a paramount pier.
All the earth was filled in and I have used this mostly over the winter. Last year all was fine.  This year I had about 1 minute of arc drift in each axis using pempro.
Recently I started noticing that my stars appeared trailed during long exposures and autoguiding was acting up.  PHD 2 told me my polar alignment was off by 4 degrees. . So today I checked my polar alignment with pempro and sure enough, 4-6 degrees off in drift.  I have put it back to within 1 minute.
I thought I was golden with such a pier. Recently we had a lot of rain and then the temperatures have been going between + 12C and -12C.  Could this be a factor?  How often do you check your alignment?
Thanks


Re: Continued: (Field curvature with Flatteners and compressors)

lmbrabec@...
 

Really cool information Roland!  Would you by chance have any data to share with TEC140FL with the QTCC?  I'm early on trying to fine tune my new TEC140FL with a QTCC and ZWO ASI294MC Pro camera to minimize star elongations in the corners of the image.  I'm curious how sensitive it might be to minor changes in the back focus versus the spec. of 80.8 mm +/- 1.0 mm (I also have the 18.3 mm spacer for use with the TEC140).  All the best, Scott


Re: Precise polar alignment of the azimuth axis

Mike Dodd
 

Because of gravity, there is always flexure. It's just a matter of
how much.

"Piggy-backed" guide scopes, even if they are light, can be subject
to flexure exerted on the rings by the primary scope.
or, if the primary scope rings are lined with felt or other soft material, the primary scope ITSELF could be moving relative to the guide scope.

I replaced the felt in my 130mm APO rings with solid styrene, as seen here: <http://astronomy.mdodd.com/flexure.html#RingLiner>

That page shows seven things I did to vanquish flexure in my system. You can never pay too much attention to tracking down flexure!

--- Mike
http:// astronomy.mdodd.com


Re: Precise polar alignment of the azimuth axis

Ray Gralak
 

Do the PA routine in SC as usual with the scope starting at Park 3. Adjust Alt and Az to get your PA to good or
excellent. At this point, your scope should be about 90 deg from Park 3. Then in SC hit the restart button. This
time, let SC plate solve with the scope at 90 deg from Park 3. Then once SC is done, send the scope back to Park
3. And without touching Alt or Az, note what what SC reports. It should still be good or excellent to show that
flexure is not a problem.
Because of gravity, there is always flexure. It's just a matter of how much.

The bigger the instrument the more flexure there will be. "Piggy-backed" guide scopes, even if they are light, can be subject to flexure exerted on the rings by the primary scope.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Cheng-Yang Tan via groups.io
Sent: Tuesday, December 29, 2020 4:11 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Precise polar alignment of the azimuth axis

Actually there is a way to see whether your guide scope is flexing w.r.t. the mount with SharpCap (SC):

Do the PA routine in SC as usual with the scope starting at Park 3. Adjust Alt and Az to get your PA to good or
excellent. At this point, your scope should be about 90 deg from Park 3. Then in SC hit the restart button. This
time, let SC plate solve with the scope at 90 deg from Park 3. Then once SC is done, send the scope back to Park
3. And without touching Alt or Az, note what what SC reports. It should still be good or excellent to show that
flexure is not a problem.

The above routine is described in SC doc:

Polar Alignment Troubleshooting – SharpCap – Lunar, Planetary, Solar and Deep Sky Imaging. EAA and Live
Stacking. <https://www.sharpcap.co.uk/sharpcap/features/polar-alignment/polar-alignment-troubleshooting>


<https://www.sharpcap.co.uk/sharpcap/features/polar-alignment/polar-alignment-troubleshooting>

Polar Alignment Troubleshooting – SharpCap – Lunar, Planetary, Solar and...





I use it all the time to make sure that nothing has moved during PA.

IMO, using the guide scope gives a more accurate PA because of its finer image scale. In my workflow, I do a
rough PA with PoleMaster (PM) and the PM scope and then use SC with the guide scope for the final PA.

Also SC tells you what your PA error is while PM just asks you to eye ball the alignment between the dot in the
square and the circle. I think having a PA error allows you to know how precise your PA is.

cytan

P.S. I've never had any success with drift align with PHD2. I think I'm just not patient enough to wait for drift to get
the error to a steady value.



On Tuesday, December 29, 2020, 04:27:13 PM CST, Ray Gralak <groups3@gralak.com> wrote:


Try the Sharpcap polar align app using the Polemaster camera.
That works for me and allows setups using Sharpcap without a guide camera.
Using the Polemaster camera is the best way to do it.

If a guide camera is used and the entire scope is rotated, there is going to be flexure somewhere, which can affect
the calculated polar alignment position.

There is only so much accuracy you are going to get with this method with a guide scope.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Greg McCall
Sent: Tuesday, December 29, 2020 1:53 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Precise polar alignment of the azimuth axis

Hi,
Re Sharpcap and Polesmaster.
Try the Sharpcap polar align app using the Polemaster camera.
That works for me and allows setups using Sharpcap without a guide camera.

Greg






Re: APCC & NINA Platesolver "sync" question

davidcfinch9
 

When I use SkyX, I do a “Closed Loop Slew” to a star, which will slew to the star, take a picture, plate solve and center the star. I then “Synch” on the star in SkyX. Is this the same as your fourth paragraph?

On Tuesday, December 29, 2020, 5:41 PM, Roland Christen via groups.io <chris1011@...> wrote:

Sync and Recal were two commands that we used from the beginning on our very first controllers.

Recal:  When you send the scope to a star, the planetarium software sends the co-ordinates to the mount where it is stored in memory. The mount moves there via the GoTo command. For example, you send (GoTo slew) the mount to a star named Accrumulous, which is at exactly 10hrs00min00sec and Dec of 45deg00min00sec. That number is now in memory in the CP controller. However, you wish to center this star in your CCDchip/eyepiece, so you move it around until it lands on the crosshairs. The new number is where the scope thinks it is pointed, but you wish for that to be the original number. So by issuing a Recal, that new number is replaced by the stored number of 10hrs00min00sec and Dec of 45deg00min00sec.

Sync: you send the mount via manual move to a spot in the sky that you are absolutely certain is the star
Accrumulous. The mount's internal co-ordinates could be anything, but you wish to replace them with
10hrs00min00sec and Dec of 45deg00min00sec. Remember, that co-ordinate is NOT in the mount's memory because you never issued a co-ordinate GoTo command to go there. So, in order to sync on that co-ordinate, your external planetarium program will send the numbers 10hrs00min00sec and Dec of 45deg00min00sec along with a Sync command. The mount controller will dutifully replace the internal co-ordinate with the new one which you sent in your sync command. A co-ordinate and sync command does NOT cause the mount to move, it is not a move command. It is only a re-alignment command.

When i use SkyX with the ASCOM driver, I will click and slew to an object in SkyX, then image and center the object via my keypad or ASCOM driver or APCC buttons. I then do a sync on the object in SkyX. Works flawlessly every time. SkyX knows the object co-ordinate, asks you if that's the one you want to sync on and then does the sync when you say YES. Bingo, done.

I don't know how else to explain it better. Maybe it's still mush?

Rolando



-----Original Message-----
From: Dale Ghent <daleg@...>
To: main@ap-gto.groups.io
Sent: Tue, Dec 29, 2020 3:54 pm
Subject: Re: [ap-gto] APCC & NINA Platesolver "sync" question



> On Dec 29, 2020, at 16:14, Xentex <michael@...> wrote:
>
> I just started using APCC and a Mach2, and my usual imaging program is NINA with ASTAP doing platesolving.
>
> My other mount is a Celestron CGEM and there is a pretty simple process to sync it to the sky when started up.  You pick a star in the mount driver's pseudo-planetarium software (CWPI), go to, center it in eyepiece, then click sync.  I generally did the centering with platesolving, and in NINA always had the "reslew to target" and "Sync" options turned on.  I never knew exactly what was happening, but didn't really care.  It just worked.

"Reslew to target" makes NINA issue another slew to the desired coordinates after a plate solve is done and the mount is updated (synced) with the results of the solve. This process repeats until the results of the successive plate solves indicate that your mount is pointing within the Pointing Tolerance of the the desired coordinates. The Pointing Tolerance is a setting found under Options > Plate Solving.  Given the wide variety and qualit^H^H^H^Hcapabilities of mounts out there, this tolerance can be large or small.

> With the Mach2, there's both a "Sync" and a "ReCal" button in APCC, and the manual explains you only want to "Sync" once per session, and you want to be pretty careful about where you're pointing when you're doing it.  I can't see my mount from where I control it, so that got me wondering whether the NINA "Sync" option is doing a "sync" or a "recal".  And then I started wondering what exactly is happening.

The NINA sync option does a classic sync through the ASCOM driver. There is no provision in the ASCOM telescope driver standard for issuing it in the form a ReCal, which is a command and semantic that is unique to A-P mounts. If set, the A-P ASCOM driver (or APPC) will transparently convert Syncs to ReCals as they are received from applications such as NINA and normally this option should be On.

> So first question, is it useful and safe to have the "Sync" option turned on in NINA's platesolve section?

Is it useful? In general, yes. In the context of the Mach2, it might be superfluous, but not deleterious, after the first time the mount is synced since the Mach2's encoders allow it to know and regulate where it is pointing in the sky without the aid of a plate solve, given a proper polar alignment.

Is it safe? It's generally safe when it's done with a non-encoder-enabled mount in the proper orientation, with counterweights down. Syncing with the mount in a cw-up orientation can end up being dangerous when the mount is told to slew to something later, and the mount dutifully does so, but drives the telescope under the mount and into the pier/tripod legs. There might be safeguards against this that I'm not aware of in the CP or APCC/ASCOM driver, though.

This brings up a good question, though - what if you're running a pointing model and the driver gets a sync? Will the sync perturb the pointing model? This, I don't know because there have been scant clear nights since I personally started using APPM back in mid-November, so maybe Ray can chime in on this. I know that Bisque's ASCOM driver for TheSkyX and T-Point contain an option to silently discard syncs issued by applications when a pointing model is active as, in their system, a sync can throw off the active pointing model.

> Second question, how am I supposed to actually use the ReCal thing in APCC?  For example, last night I wanted to center a particular star as part of an alignment routine.  I used Stellarium to command the mount to the star.  It wasn't quite centered, so I platesolved with the "reslew" and "sync" options on.  To my surprise, it wouldn't center.  And to my even greater surprise, when I tried to figure out why I noticed that APCC, Stellarium, and the plate solver all showed different RA/Dec for where the center of the frame was.  There was about an arcmin difference between them.

You were probably within the aforementioned Pointing Tolerance and NINA determined that there was no need to reslew. Coincidentally, the default value for NINA's Pointing Tolerance setting is 1 arcmin. Reduce this tolerance to force the centering process to be tighter. Not many mounts are capable of such accurate pointing, hence NINA's generally conservative default of 1 arcmin.

/dale







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Roland Christen
Astro-Physics

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