Patent ID: 8183809

Claim:
A method of operating a drive device of an electric motor, comprising: determining a sequence of setpoint values for the electric motor; providing the drive device with the sequence of setpoint values by a higher-level drive control unit via a communication link; determining, based upon the sequence of setpoint values and corresponding actual values, current setpoint values for the electric motor; providing a drive unit of the electric motor with the current setpoint values or, based upon the current setpoint values and corresponding current actual values, determining trigger signals for a plurality of circuit-breakers, the electric motor being connected in accordance with the respective current setpoint value to a power supply via the circuit-breakers, and supplying the trigger signals to the circuit-breakers; deciding, based upon first signals supplied from outside to the drive device, whether an actual value of the electric motor for compliance with an actual-value condition is monitored, monitoring mode; causing automatically the electric motor to be disconnected from the power supply in the monitoring mode when the actual value does not comply with the actual-value condition; providing the drive control unit with first information revealing whether the drive device is in the monitoring mode, the first information being provided via the same communication link by which the sequence of setpoint values is provided to the drive device by the drive control unit; and providing the drive control with second information revealing a nature of the actual-value condition, the second information being provided at least in the monitoring mode and via the same communication link by which the drive device accepts the sequence of setpoint values from the drive control unit.