基于自由口模式的超声水表与S7-200通信实现  

Communication Between Ultrasonic Water Meter and S7-200 Based on Free Port Mode

作　　者：张继川 ZHANG Jichuan(Huizhong Instrumentation Co. Ltd., Tangshan, Hebei 063020,China)

机构地区：[1]汇中仪表股份有限公司,河北唐山063020

出　　处：《微型电脑应用》2020年第6期139-140,147,共3页Microcomputer Applications

摘　　要：由于S7-200型可编程控制器预设的通信协议与SCL-61D超声水表通信协议不兼容,若进行通信需要更换设备,增加了成本。因此,利用S7-200型PLC的自由口通信模式,通过编程实现了对智能超声水表SCL-61D的数据读取。重点研究了通信参数的初始化及自由口通信程序的设计,通过PLC读数与SCL-61D超声水表真实数据对比可知,具有稳定性高、实时性好、安全可靠、成本低等特点,为PLC与智能仪器仪表通信协议不兼容问题,提供了解决思路。Due to the incompatibility between the preset communication protocol of S7-200 PLC and the communication protocol of SCL-61d ultrasonic water meter,the equipment needs to be replaced for communication,but the cost is increased.Therefore,in this paper,the free port communication mode of S7-200 PLC is used to realize the data reading of intelligent ultrasonic water meter scl-61d by programming.This paper focuses on the initialization of communication parameters and the design of free port communication program.By comparing the PLC reading with the real data of SCL-61d ultrasonic water meter,it can be seen that this design has the characteristics of high stability,good real-time performance,safety and reliability,low cost,etc.,which provides a solution to the incompatibility between PLC and intelligent instrument communication protocol.

关 键 词：超声水表 可编程控制器 XMT指令 特殊存储器 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]