Abstract: This invention features a device for controlling the operation of a pneumatic actuator and a pneumatic actuator having such a control device. More particularly, the actuator control device of the instant invention includes a housing mounted to an actuator end cap, a solenoid valve disposed within the housing and a gas control valve that controls the pressurized gas admitted to and exhausted from the actuator for valve actuation. The gas control valve is responsive to the solenoid valve and is mounted to the housing. Preferably, the control device includes a position indication mechanism, disposed within the housing, that determines a prespecified position of the valve responsive to the movement of at least one and preferably two moveable actuator probes extending from the actuator end cap into the housing. The gas control valve is a spool valve that is pneumatically controlled by the solenoid valve.

Abstract: A digital positioner is used to control and operate an AC electric valve actuator. A valve interface control program (ICP) provides a PC-based interface to the valve positioner or positioners. The ICP allows parameter modification, monitors alarm conditions, and provides a display of calibration data.The positioner has a security code to prevent unauthorized access; adjustable independent valve open and close ramp times; electronic valve actuator travel limits; programmable setpoint direction; programmable signal split range; manually adjustable deadband and an auto-adjusting setting; and high positioner resolution.The ICP can command the positioner to do the following: set the value of a specified parameter; read the value of a specified parameter; control the positioner setpoint from a remote computer; request the positioner to return the present status; read the byte value in a specified EEPROM location; set the value of a specified location in EEPROM memory; and select system operating mode.