When the mount is in counterweight-up position and BYN triggers a dither, the mount first returns to counterweight-horizontal position to move the small increment,

When you are in counterweight up, the mount moves according to the safety protocol. There are two ways to move a mount.

First is to simply issue a timed move. Example: I want to move 15 arc sec, so I issue a command to move for 1 second at 1x sidereal. This will not rigger a safety move. The mount will instantly move to the correct point and not return to the counterweight down position.

Second is to issue a coordinate command move. Example: Move mount coordinate by 15 arc seconds. This will trigger a safety slew as you experienced.

The fact that 3rd party developers don't understand the difference and consequences causes them to use the wrong approach to dithering, and thus you end up with the extra wasted move. It is not the mount's fault, it is doing exactly what it should do.

Rolando

-----Original Message-----
From: Joseph Beyer <jcbeyer2001@...>
To: main@ap-gto.groups.io
Sent: Thu, May 28, 2020 1:54 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

I need to try out SGP direct dithering. 

When direct dithering using BYN it works fine when the mount is in counterweight-down position. When the mount is in counterweight-up position and BYN triggers a dither, the mount first returns to counterweight-horizontal position to move the small increment, I assume is in the DEC axis, then returns to the imaging position. Clearly not an economy of motion. George says this is due to BYN not being able to work through the ASCOM V2 safety protocols. If I understood his message correctly SGP is able to use the V2 protocol.  It should be able to move the several pixel distance without first moving the degrees of RA distance.  

Hopefully SGP works more efficiently. I’d like to be able to keep the option to image without guiding in the counterweight-up position and direct dither. If not, the next best thing would be as Roland recommended leave PHD2 at an idle and just use it for dithering. It seems to work fine with the counterweights up. 

Joe

On May 28, 2020, at 11:00 AM, uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:



So, when using the keypad quick method, what happens after a meridian flip?

You would need a model for the path that the object takes, one on either side of the meridian.

For some objects you may be able to start the scope under the mount and image all night long without ever flipping. It depends on the amount of clearance you have at the back of the scope before it hits the pier or tripod legs. With my short scope (130EDF) i can start under the mount for any object that's just south of the zenith. With the long 160 refractor it clears the tripod legs about 18 degrees south of the zenith.

Starting under the mount I can image the same object from dusk to dawn without flipping. I would then do a model of 8 points every 1.5 hours or so along the path.

Otherwise, if you flip, you will do a separate model on each side. Of course, doing the entire sky manually would take a lot of time. So if that's the goal, I would just let APCC Pro do it automatically.

Rolando

-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Thu, May 28, 2020 12:12 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

On Thu, May 28, 2020 at 09:35 AM, uncarollo2 <chris1011@...> wrote:

Right now we have not integrated plate solving, but this may be added in the future to make the cycle faster. Remember, this is just a quick way to achieve unguided imaging for an object that you wish to image all night long. Doesn't require super perfect polar alignment, although you want to be close to prevent field rotation.

Assume that the mount will be taken down and then set up for each use.

So, when using the keypad quick method, what happens after a meridian flip?

Will I need to re-do it again? ... or would doing the automated APCC full sky model be the best approach?
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
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