Control device for a pneumatically operated actuator
View Patent ↗The disclosure relates to a control device for a pneumatically operated actuator in the field of process automation, in particular for continuous control of material flows in the industrial environment. The control device has a communications interface for receiving an electrical setpoint value, and an output for the output of a pneumatic fluid, whose pressure is varied as a function of a control deviation. The received electrical setpoint value is suitable as a process parameter. The control device is connected via a communications channel to an actual-value encoder, which is designed to output an electrical signal corresponding to the actual value of the same process parameter.
1. A control device for a pneumatically operated actuator for actuating a process valve in order to control a material flow in a pipeline, said control device comprising:
a communications interface for receiving an electrical setpoint value, and varying at its output, the pressure of a pneumatic fluid as a function of a control deviation,
wherein the received electrical setpoint value is suitable as a process parameter, and the control device including a second interface connected via a communications channel to an actual-value encoder, the second interface is for receiving an electrical signal output by the actual-value encoder corresponding to an actual value of the same process parameter, and for receiving diagnostic data from the actual-value encoder
wherein the actual-value encoder evaluates the actual value of the process parameter to diagnose a condition of at least one of the process valve and the control device, and
wherein the actual-value encoder is a differential pressure transducer which measures pressure and differential pressure and internally evaluates raw data to perform a diagnostic function of at least one of the process valve and the control device.
2. The control device as claimed in claim 1 , wherein the actual-value encoder has a fieldbus interface, and is connected via this to a communications channel implemented as a fieldbus.
3. The control device as claimed in claim 1 , wherein the actual-value encoder is connected via a direct connection to the control device.
4. The control device as claimed in claim 3 , wherein the direct connection is formed by a wireless communications channel.
5. A control arrangement for a pneumatically operated actuator for actuating a process valve in order to control a material flow in a pipeline, the control arrangement comprising:
a control device having a communications interface for receiving an electrical setpoint value, and varying at its output the pressure of the pneumatic fluid as a function of a control deviation, the received electrical setpoint value being suitable as a process parameter;
and a second interface, an actual-value encoder connected via a communications channel to the second interface of the control device, the actual-value encoder being configured to output an electrical signal corresponding to the actual value of said process parameter, and to output diagnostic data
wherein the actual-value encoder evaluates the actual value of the process parameter to diagnose a condition of at least one of the process valve and the control device, and
wherein the actual- value encoder is a differential pressure transducer which measures pressure and differential pressure and internally evaluates raw data to perform a diagnostic function of at least one of the process valve and the control device.
6. The control device as claimed in claim 1 , wherein the actual-value encoder is used as a microphone to detect at least one of valve noise and process noise in the process medium.
7. The control arrangement as claimed in claim 5 , wherein the actual-value encoder is used as a microphone to detect at least one of valve noise and process noise in the process medium.