The Gemini and SGP work together just fine but you have to observe some “protocol” in the way things are initialized. I don’t currently have access to my Gemini but as I remember, in the “settings” dialog, there is an option in the “Rotator Configuration” dialog box that says “Reverse Direction.” You must have this option checked. Otherwise, SGP will move the rotator in the wrong direction when moving to a specified position angle.
When you startup the Gemini Commander software, the first thing to do after connecting to the rotator is to home the rotator. This will cause the Gemini to move from its current position to an internal position of 75 degrees; then it will reverse and move to 0 degrees internal position angle. From now on the only thing you will ever do with Gemini Commander is to enable / disable temperature compensation.
Now connect SGP to your rotator. SGP will retrieve the Gemini’s internal position angle (0) and display that.
Point the scope somewhere and do a Solve and Sync. This will sync both the mount and the rotator. SGP will now display the camera’s sky position angle. At this point, SGP knows how to map the camera’s sky position angel to the Gemini’s internal position angle.
In SGP, enter the position angle you want the camera at and click set. SGP will then move the rotator to that position. If you now look at the position angle reported in Gemini Commander, it will be completely wrong. Forget about it; don’t attempt to make the sky pa in Gemini Commander be “correct.” The angle reported in SGP is correct.
You can move the Gemini to the desired position either by entering the sky pa in SGP or put the sky pa in the Target Settings dialog box and check “Rotate Camera To” option. SGP will move the rotator to the specified position when the target starts.
But its important to remember not to ever use the Gemini Commander software to move the rotator to some specific position angle. Only move the rotator with SGP. It is also important to do that first Solve and Sync to give SGP the beginning sky pa.