New feature request focuser

Hi team,

First of all thanks for all the great work you are doing to SGP! It is much appreciated!

I have a feature request because SGP is not able to pickup my previous focuser position once SGP is restarted or the focuser is disconnected and then reconnected.

Would it be possible to provide an option to set the focuser position without sending a focuser move IN or OUT command to the focuser? E.g. I would tell SGP the focuser is on position 2500 without it sending a command to take 2500 steps in or out to the focuser so that it actually would go to position 5000 (because it was already on position 2500 before the focuser was disconnect).

Unfortunately not through SGP. The ASCOM Focuser does not provide a “Sync” functionality which is what we would need to be able to set the position of the focuser without moving it. You may be able to do this with your focuser driver though. I know my MoonLite controller will allow me to set the initial position through their ASCOM driver itself. But it also saves position between power cycles. It may be worth emailing your focuser hardware provider to see if they can persist the position between power cycles as it sounds like that’s what you’re really after.


I was already afraid you were going to respond this way. Unfortunately the problem is in the ASCOM driver of the home made auto focuser and I don’t hold the source code of it to debug it and recompile…

If a sync command would be a useful addition to the ASCOM focuser driver specification then it could be added.

What is needed is:

  • A commitment by at least one application developer to implement code to use this.
  • A commitment by at least one driver developer to implement code to use this.

Given this then something could be added to the specification. There’s a fair amount of work in extending the specification, it needs updating the specification, DriverAccess, the simulator, the driver templates and conform. Nothing that’s impossible but it’s reasonable to expect that this will actually be used.

This won’t be an instant fix and won’t solve this problem unless the author of this particular driver implements the change and so does SGP.