OPERATING SPEED CONTROL DEVICE FOR ELECTROPNEUMATIC POSITIONER

PROBLEM TO BE SOLVED: To provide an operating speed control device for an electropneumatic positioner, capable of preventing sudden and great operation of a control valve when an actuator controlled variable is greatly changed in accordance with a PID control signal. SOLUTION: The operating speed control device comprises a data comparison part 12 for determining the actuator controlled variable output from a controlled variable command part 5 while comparing it with an updated value output from the actuator controlled variable, an operating speed setting clock oscillation part 14 for varying the operating speed of the electropneumatic positioner, an addition command switch 15 to be turned on when it is greater than a digital value oscillated by the operating speed setting clock oscillation part, a data addition part 16 for adding a constant "1" to the digital value, a subtraction command switch 17, a data subtraction part 18 for subtracting the constant "1" from the digital value when the subtraction command switch is turned on, and an output data selecting switch 19 for adding or subtracting the constant "1" in accordance with an output signal from the data subtraction part to update and output the digital value. COPYRIGHT: (C)2008,JPO&INPIT