Method for detecting the drive type of an actuator (II)

A method for detecting the drive type of an actuator having a positioner for operating a final control element, the positioner comprising an electronic control unit, which uses a microcontroller to receive one or more input signals, and to output actuating signals to control the flow of gas to or from the chambers of a single-acting or double-acting pneumatic drive, with the pressure being monitored in at least one pneumatic fluid supply line to the chambers of the drive, and with the position of the final control element being signaled in the positioner by a rotational measuring system, wherein

• during commissioning, the actuator is moved over a definable distance within its operating range,
• the pressure in at least one pneumatic fluid supply line to the chambers of the actuator is monitored and recorded,
• the angle positions fed back by the position feedback sensors are recorded with the corresponding pressures,
• the drive volumes and the relationship between the drive volumes and the position signal are found from the fed back angle positions and the associated pressures, and are compared with transfer characteristics of known drive types, and
• where there is a match between the transfer characteristic, defined by the relationship between the drive volumes and the position signal of the given actuator, and one of the transfer characteristics of the known drive types, the identified drive type is assigned to the given actuator.