A controller for monitoring and controlling an operating pulsator in a milking system is shown. The controller receives a start signal generated when a milking apparatus is attached to a cow. A first sensor is operatively connected to a designated pulsator for receiving a pulsating vacuum and for producing a first signal representing the pulsating vacuum level. The controller includes a processor having a comparator for comparing the first signal to a stored reference of predetermined vacuum ranges and for generating a control signal when the designed pulsator pulsating vacuum level is outside of a predetermined vacuum range. A control circuit signals that the designated pulsator pulsating vacuum level is outside of the predetermined vacuum range.