Abstract: A controller for controlling an electric or a fluidic valve drive. The controller includes a communications interface which is configured to output a current signal and convert drive-related measurement information into a current signal level within a current interval according to a communications protocol. The communications interface is further configured to convert at least two different items of device status information into different current signals levels outside of the current interval.

Abstract: A communication device for a field device for transferring output information to a controller, including a passive digital output with a first connection point and a second connection point, a circuit arrangement connected between the first connection point and the second connection point, and a control device configured to selectively put the circuit arrangement into one of a plurality of switching states according to the output information to be transferred. The communication device is configured, in a state in which the passive digital output is connected to the controller, to provide an electric output signal with a first signal value according to a first communication protocol at the connection points in a first switching state of the circuit arrangement and to provide the electric output signal with a second signal value according to the first communication protocol at the connection points in a second switching state of the circuit arrangement.

Abstract: A communication device for a field device for transferring output information to a controller, including a passive digital output with a first connection point and a second connection point, a circuit arrangement connected between the first connection point and the second connection point, and a control device configured to selectively put the circuit arrangement into one of a plurality of switching states according to the output information to be transferred. The communication device is configured, in a state in which the passive digital output is connected to the controller, to provide an electric output signal with a first signal value according to a first communication protocol at the connection points in a first switching state of the circuit arrangement and to provide the electric output signal with a second signal value according to the first communication protocol at the connection points in a second switching state of the circuit arrangement.

Abstract: A controller for controlling an electric or a fluidic valve drive. The controller includes a communications interface which is configured to output a current signal and convert drive-related measurement information into a current signal level within a current interval according to a communications protocol. The communications interface is further configured to convert at least two different items of device status information into different current signals levels outside of the current interval.