Reference frame for MATLAB-SimPowerSystems' asynchronous machine model measurement signals (e.g phiqr,phidr)

I am trying to understand in which reference frame MATLAB-SimPowerSystems' "Asynchronous Machine Model SI unit" calculates various measurements signal (e.g phiqs, phids) . I selected synchronous reference frame in the GUI of the model. But it seems measurement values are not in the synchronous reference frame. By synchronous reference frame I mean reference frame which is rotating at speed equals to the machine speed plus slip speed. It seems measurements signals are in the reference frame which rotates at fixed speed corresponding to the frquency input given in the GUI (Parametrs tab). When input supply frequency matches with the Parameter tab's frequency then only I am getting perfect dc value of d axis rotor flux (phidr) and q axis rotor flux (phiqr) signals .If my understanding is correct then in steady state phidr and phiqr in synchronous reference frame should always be constant (dc) . It would be helpful if someone can can throw light on how to measure signals in synchronous reference frame.