I am trying to use the Red Pitaya in the bare PID mode for stabilzation at a constant voltage (not arbitrary frequency locking.) To do this I want to use the offset on the error signal and lock to DC frequency. Is there a way to instead lock to a constant output signal?

Moreover, I configured my Red Pitaya in HV mode for input 1, but it seems I could not input offsets of more than 1 V.