Pneumatic actuator valve control mode

Now there are more and more pneumatic valve actuator control methods and techniques. In actual industrial life and industrial control, the methods used to control pneumatic actuators are commonly used as follows.

PLC is used more and more widely in the control system, because this program is developed on the PLC of OMRON, the PLC to make an introduction

Hardware components: 1 computer, 1 set of PLC (including CPU,I/0 module, ID21003 module) relay, 2 solenoid valves, 1 pneumatic valve actuator. The principle of its composition is as follows: the PC connects to the PLC of 0MRON through Rs-232 crosstalk communication, and the PLC is programmed and monitored. PLC I/0 module is respectively connected to the output signal, during which the input module is connected to the two position sensors on the valve, through the PLC input module ID211 indicator light sequence to flash the valve switch state. Input mode adopts two valves to detect pulse pulse input, that is, pulse pulse A and pulse pulse B in the running state, when pulse A input indicator light A, pulse pulse input indicator light B. Input sequence is AB, indicating open valve. The input order is BA to indicate the closing valve. It is necessary to partially overlay the valve detection pulse A and B signals, otherwise the valve opening can not be detected normally

Through the PLC output module 0C225 control of two relays, relays have two groups of normally open normally closed output contact, 1 for the open valve output contact, 1 group for the valve to close the contact. When opening the valve, when the valve opening is greater than or equal to the set valve limit value, it will open the valve output contact action when the valve opening is less than the set valve limit value, it will open the valve and it will open the valve reset when the opening is less than the limit value. When closing the valve, when the valve is closed to zero and there is no pulse input within 21s, the valve output contact action; If there is pulse input in 21s, then delay 21s shut-off valve output contact action. The switch of two solenoid valves is controlled through the suction of the relay. After the solenoid valve is opened, the pneumatic valve actuator can be controlled to make the valve do the corresponding opening or closing action. At the same time, the proximity sensor to the valve switching condition is transmitted to the PLC, and compared with the required valve opening