【摘要】 在天然气门站自动控制系统中,基于串行通讯的工艺节点数据采集已得到广泛应用。文章提出了面向天然气门站流量计量,基于PLC测控系统的串行通讯数据采集问题,给出流量计布局方式、串行通讯数据采集系统结构及MODBUS通信协议的PLC数据采集实现方法,对于RS—485总线串行数据采集的PLC自动测控系统的构建有一定的指导意义。更多还原

【Abstract】 In the automatic control system for gas station,The process is widly to be used based serial communication data acquisition.In this paper,faced flow quantity monitoring and measurement in the gas station,based serial communication data acquisition problems by PLC measurement and control system,it is given the way to layout of the flowmeters,the architecture of serial communications systems,and modbus protocol of the PLC data acquisition.it is important to make up PLC data acquisition System for automatic monitoring and control by RS-485 network or extend.更多还原