Jean-Francois Pittet wrote a script for Sharpcap to automatically record a spectroheliogram with a display of the Doppler effect on the Sun. Since the scanning direction in this case is not in the RA or DEC direction, but rather oriented according to the position of the sun's axis, a rotator was mounted on the spectroheliograph.

The script and its description can be found here:

SolEx Group:

https://groups.io/g/Solex-project/topic/94372077#msg11799

Solarchat Forum:

https://solarchatforum.com/viewtopic.php?t=48984

This allows the orientation of the spectroheliograph to be adjusted remotely.

Yours, Karsten

Links for further explanations:

https://www.teleskop-spezialisten.de/shop/Observing-the-sun/Spectroheliography/05-Observation-with-SolEx-SolEx::6038.html?language=en

https://www.cloudynights.com/topic/574571-solar-differential-rotation-measured-with-a-spectroheliograph/