Does PIDAdvancedCC:Gain Scheduling work with internal setpoint as reference
Well you can make it work this way by looping the working setpoint back to the external gain scheduling input terminal.
I think however, that this would be a very unusual thing to do. Your gain scheduling would normally depend on your ACTUAL process conditions (i.e. your current PV or current error etc) not your target process condictions (i.e. your SP)
Im not going to say this is wrong, but are you absolutely sure this is REALLY what you want ?