To easily grasp the trouble or the ambient environmental data of a valve by providing an auxiliary input terminal to which a signal from various sensors can be inputted to transmit a sensor signal to a host system through a field bus.
The data of the valve opening of a valve 14 is stored in a random access memory 24 through a field bus 11 from a host system. A microprocessor 25 executes the arithmetic operation of the stored data to drive the valve 14 by a valve driving part 28. The displacement of the stem of the valve 14 is detected by a displacement sensor 32, and the displacement data is stored in the random access memory 24 by the microprocessor 25, and control is performed by the arithmetic procedure of a read only memory 23 so that it accords with previously stored data. Also, the microprocessor 25 transmits the data of an air supply pressure sensor 29 and an output pressure sensor 30 through a multiplexer 33 to the host system at request of the host system to monitor the existence of a malfunction. Accordingly, an air supply pressure and an output pressure can be immediately and easily monitored by the host system in an emergency.
KOMIYAMA CHIFUYU
NISHIJIMA TSUYOSHI
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