Thank you, @hjnet , for detailed steps. Your post enabled me to connect my Alt-Az mount (Synscan HC) with ASIAir plu.
However, I came across another issue. Goto with auto-center keeps failing. Goto takes my scope within 0.5 ~ 1 degrees of a target object. However, subsequent plate-solve (it works well) and centering never brings the scope closer to the target.
With SW Synscan Beta, the distance is even farther than SW Synsscan .
@hjnet, does goto + auto-centering work for you?
My telescope is Orion XT10G with Synscan HC v4.