Application of PLC in Low-voltage Control System of Electrostatic Precipitators

Based on the practical requirement of Electrostatic Precipitators(ESP)in the purifying process of powder dust pollution,SIEMENS S7-200 PLC was adopted as heart part to design the low-voltage controller system of ESP.Through asynchronous parallel port,field temperature acquisitlon has been accomplished by gating time sequences method which was realized by ordinary switch input.Programs and approaches which were used to collect temperature and control heater in the low-voltage system were given out.Practical operating has proved that the approach is rational and effective.