Sequencer: Sync to previously saved -> how to save ?

[Tom°Dresden]

Hello,

there is a sequencer command "Sync the mount to a set of coordinates that where previously saved" .
How can I save (or determine) these coordinates for sync ?

I try to direct the mount to a defined position and then tell the mount to sync to this position.
Something like align.

ASCOM (or LX200 in my case) knows commands to define a target (RA,DEC) and also SYNC to target.
How can I do this in sequencer of Sharpcap ?

I found sequencer commands to GOTO a target, but none to simply define a target.

Regards,

Thomas

[admin]

Hi,

there are a couple of steps that can set the saved co-ordinates

* Plate solve and save co-ordinates
* Save the current mount co-ordinates

there's also another step that uses the saved co-ordinates

* Move the mount to a set of co-ordinates that were previously saved.

These are designed to be used in pairs...

* Save the current mount co-ordinates
* Do other stuff that potentially moves the mount
* Move the mount to previously saved co-ordiantes (going back to where you were)

and...

* Plate solve and save co-ordinates
* ... optionally do other stuff ***
* Sync the mount to previously saved co-ordinates

The 'saved' co-ordinates are only there to be re-used by the later steps in the same sequence - they are cleared when the sequence ends and sequences start with no saved co-ordinates, so there is no real need to inspect them.

There is no real equivalent in the sequencer to define a target - if you are writing a custom sequence then you would use two steps

* Goto target (RA,Dec) - move the mount
* Set target name to <name> - get the name set so that it is used in filenames

After that you could use the 'save current mount co-ordinates' step to save the target position in case your sequence needs to return to it later.

Selecting a target is handled differently - look at the 'Goto Catalog Target/Co-ordinates' tool to see how you can pick a target from the catalog. If you want to do this in the context of the sequencer, the 'Deep Sky Sequence Planner' has this functionality and will build a typical sequence for you without the complexity of the main sequence editor.

cheers,

Robin

[Tom°Dresden]

Hi Robin,

if you are writing a custom sequence then you would use two steps

* Goto target (RA,Dec) - move the mount
* Set target name to <name> - get the name set so that it is used in filenames

this is an 'hen and egg' problem, an uninitialized mount won't do any GOTO.

ASCOM knows a "set target RA/DEC" and also SYNC command, I would need these in the sequencer.

What I do until now: Open CdC, mark mount position (usually Polaris), choose "sync mount to position", then close CdC and open SC ...

Is it please possible to have the "set target RA/DEC" command in SC sequence ?

Regrads,

Thomas

Edit:
I mean these ASCOM commands

​/telescope​/{device_number}​/targetdeclination
Sets the target declination of a slew or sync.

/telescope/{device_number}/targetrightascension
Sets the target right ascension of a slew or sync.

/telescope/{device_number}/synctotarget
Syncs to the TargetRightAscension and TargetDeclination coordinates.

[admin]

Hi,


I'm still not quite sure I follow the reason that you need this. There are two ways to do things in ASCOM

1) Set target co-ordinates and then GOTO or SYNC to target (SlewToTarget, SyncToTarget)

2) Perform a GOTO or SYNC by providing the co-ordinates as part of the ASCOM method call (SlewToCoordinates, SyncToCoordinates)

both achieve the same goal in the end - SharpCap uses the second approach exclusively and doesn't use the ASCOM target property at all, so
the sequencer is designed around that approach - when you want the mount to move somewhere, the co-ordinates are part of the GOTO movement step.

If you really want to access the ASCOM target side of things, you have to use SharpCap's python scripting, where you can do things like

Code: Select all

SharpCap.Mounts.SelectedMount.AscomMount.TargetDeclination=-5
SharpCap.Mounts.SelectedMount.AscomMount.TargetRightAscension=5
SharpCap.Mounts.SelectedMount.AscomMount.SlewToTarget()

You can also save code for the scripting language in a .py file and then there is a sequencer step to run script from a save python code file.

cheers,

Robin

[Tom°Dresden]

Hello Robin,

2) Perform a GOTO or SYNC by providing the co-ordinates as part of the ASCOM method call (SlewToCoordinates, SyncToCoordinates)

Exactly this SyncToCoordinates, how can I do it in SC sequencer ?


Thomas

[admin]

Hi,

you can't do it for arbitrary co-ordinates (ie there is no way to do SyncToCoordinates(RA=14, Dec=+23) ). You can do it for results saved from a previous plate solve using the 'plate solve and save co-ordinates' step. I suppose in theory you could also do a 'save the current mount co-ordinates'.

It sounds like a step to 'save these co-ordinates for later use RA=???, Dec=???' may be useful for you?

cheers,

Robin

[Tom°Dresden]

Hello,

you can't do it for arbitrary co-ordinates (ie there is no way to do SyncToCoordinates(RA=14, Dec=+23) )

It depends what you mean with "can't do" .. yes SC sequencer can't do it, that is the whole reason why I ask for such a sequencer step all the time.

Any mount or planetary program and SC in general can do it by all means.
If SC do a 'Platesolve AND Sync' then this SYNC is what I mean and want as separate step. The result of platesolve are coordinates RA/DEC (arbitrary, can be anywhere), and SYNC just syncs the mount to those cooordinates.

It sounds like a step to 'save these co-ordinates for later use RA=???, Dec=???' may be useful for you?

I don't need these coordinates any more if sync to them is done once.

But, if SC sequencer can do a SYNC to these saved coordinates, then yes such a step would be useful.

So sequence is
1. Save RA/DEC
2. SYNC to prevoisly saved RA/DEC

It is the same as just 'SYNC to RA/DEC' ?

Regards,

Thomas

[admin]

Hi Thomas,

I'm afraid I still don't understand why a step like

Code: Select all

Sync to co-ordinates RA=XXXX, Dec=YYYY

would be particularly useful. If the co-ordinates are part of the step then they would need editing frequently as the 'sync' co-ordinates that you want are not always the same. If you want to sync using plate solving then there are ways to do that already

* Plate solve a single frame and sync the mount only
* Plate solve, sync and re-GOTO
* Plate solve and save coords followed by Sync to saved co-ords

Back at the start of the thread you were mentioning the ASCOM 'Target' - do you want to be able to recover and use that target information in a sequence?

I apologise for having to keep asking, but I am really not sure of what the end result is that you are trying to achieve, so I am struggling to see what might be the best option.

thanks,

Robin

[Tom°Dresden]

Hi Robin,

I'm afraid I still don't understand why a step like
CODE: SELECT ALL

Sync to co-ordinates RA=XXXX, Dec=YYYY
would be particularly useful. If the co-ordinates are part of the step then they would need editing frequently as the 'sync' co-ordinates that you want are not always the same. If you want to sync using plate solving then there are ways to do that already

The coordinates are always the same.

You switch on your mount. There is a fixed position (sometimes called 'Park position') where the mount start operating, and where you park the mount after you finished imaging.
Some mounts can, internally, store this position. And some mounts can not store. I have a mount that can not store park position.
I switch on the mount, always at a fixed position, but mount don't know where it points. But I know. So I only want top tell the mount "you are pointing at RA/DEC ..., please use this as your start position. And then, as next step, GOTO desired imaging position, do a plate solve etc. etc.

Yes I could also start with an additional plate solve. But, it takes time, it can fail, and .. why should I do a plate solve if I already know the position ?

What I do up to now: Start CdC, connect mount, mark my parking position, choose "sync to marked position' in CdC, stop CdC, start SC, ...

I want to save this steps with CdC. It takes time, sometimes connection CdC to mount don't work because I changed setup, etc. ect.

I thought it was quite easy to sync the mount, Platesolve AND sync does that too, just omit the platesolve and specify RA/DEC directly. But that doesn't seem to be possible in SC, I didn't realize that.

I can just continue to use the steps with CdC as they work, it's not that bad.

I am also not a native English speaker, maybe I can't explain all this properly, sorry for the long discussions.

Regards,

Thomas

Sorry I forgot this your question

Back at the start of the thread you were mentioning the ASCOM 'Target' - do you want to be able to recover and use that target information in a sequence?

I want to SET or DEFINE the target. At the beginning of an SC sequence there is no target. The sequence begins with , how should I explain this, with just nothing. No target, not in the mount internally stored, and not in the SC sequence.
I do not want to recover the target, because there is no target. I want to set the target.

What I want:
- define or set a target, with RA/DEC
- and the SYNC to target

[admin]

Hi,

brilliant - thanks for the explanation, it makes sense now that the fixed location you want to use is the startup position of your mount. I had not even imagined that a mount might not power on with at least the park position set as the co-ordinates!

So, if I add a new step to SharpCap's sequencer

Code: Select all

Save Co-ordinates <RA,Dec> for later use

Then you could write a 2 step sequence

Code: Select all

Save Co-ordinates <ParkRA, ParkDec> for later use
Sync the mount to a set of co-ordinates that were previously saved

Running that sequence will tell the mount it is at the part position, and you are set to go.

That should be simple, so I will add for the next update.

cheers,

Robin