Moravian Xternal FW...filter change..during exposure

Continuing the discussion from Software starting Sequence SGPro, PHD CDC:


I don’t think we can be of much help. Our code for filter wheels has been in place and operational for more than 2 years now. Every known filter wheel seems to operate just fine (except possibly the Moravian). I don’t say this lightly, but the data supports that SGPro is likely not an issue in this equation. I cannot speak for APT’s coding practices so it’s not really a valid comparison.

You should not need to do this, but if your filter wheel requires it, you can add sort of a settling time before SGPro will start imaging after a filter change:

If you want to post logs when this happens we can see if we are able to help you track this down.

Hello Ken,
the use of filter delay brings no solution…it counts down…changes filter…while exposure starts …if i get CS i will give sgpro a chance…i will report

The ASCOM driver for the Moravian camera also controls the filter wheel and it is designed only to set the filter wheel to the commanded position at the start of the exposure.

When SGP sets a filter position all that happens is that the required filter position is set. The filter does not move at this time.

It looks as if when an exposure is started the Moravian camera driver will set the filter position and wait for the filter wheel to reach the correct position before starting the exposure.

SGP can’t change this and setting a settle time won’t have any effect.


Thanks Chris. I feel like I knew that at one time. Given this behavior, I don’t see that it would really impact your use of SGPro except for being off by a few seconds. That said, this timer is just an estimation of when your camera might be ready to give us an image. We won’t cut the exposure short if our count ends before the camera’s. When the camera says it’s ready we will grab it and move on.