关键词:天然气调压站,PLC,通信,智能监控,Modbus协议 ABSTRACT The supply of conduit gas spreads widely because of its advantages such as:convenience,economy,and safety etc,It gradually replaces the bottle packing gas.Gas is flammable and explosive.In order to ensure the safety of gas supply and realize the best adjustment,we must master the status of the system and datas such as pressure,flux,temperature in time,so the develpoment of the system is based on the 224XP is used as controlling core of the system and the sensors as measuring component and the electromagnetic valves and the relaies as executive unit.CPU not only need to deal with analog signal from EM231,but also is responsible to communicate with flowmeter and master computer to complete the whole control mission,thus it realize the purpose of parameters controlling,warning instruction and controlling the action of related electromagnetism valve. firstly,the thesis analyse the significance of the intelligent supervision of the gas station.Confirms system function goals and performance parameters,and then putsforward the designing overall frame and dividing into function modules.