基于Modbus/TCP与Ethernet/IP的输煤系统互联通信设计

Design of intercommunication of coal handling system based on Modbus/TCP and Ethernet/IP protocol

大型火电厂由于分期建设存在多套输煤程控系统,各输煤程控系统可能使用不同品牌可编程控制器(PLC),使得各系统之间无法集中控制和资源共享。本文以某电厂一期和二期输煤程控系统的网络互联通信为例,在分析Control Logix PLC和Quantum PLC 2套系统控制特点的基础上,提出利用Micro Logix 1400 PLC进行网络通信协议转换,构建基于Modbus/TCP和Ethernet/IP协议的网络互联架构。在编译软件中对各PLC进行地址规划后,Quantum PLC利用数据类型转换功能块将控制设备的开关量组合成16位控制字;然后Micro Logix 1400 PLC通过MSG模块读写Quantum PLC设定的控制字,再与Control Logix PLC进行通信,从而实现Control Logix PLC和Quantum PLC的数据交换,使2套输煤程控系统实现数据共享与设备互联。经过3年的实际运行表明,互联系统设备响应速度快,数据读取准确,大幅提高了输煤系统的可靠性和工作效率。

There're several sets of coal handling program control systems during phased construction of large thermal power plants.Centralized control and resources sharing can't be achieved among various systems due to using different brands of programmable logic controller(PLC).By taking the intercommunication between the first phase and second phase coal handling program control system of a power plant as the example,the MicroLogix 1400 PLC is used to transform the communication protocol based on analyzing the control characteristics of ControlLogix PLC system and Quantum PLC system,and the architecture of intercommunication network is constructed based on Modbus/TCP and Ethernet/IP protocol.After address planning of each PLC in compiling software,the switching values of control equipment are combined into 16-bit control word by using data type converting function block of Quantum PLC.Then,the control words set by Quantum PLC are read and written by MicroLogix 1400 PLC through MSG module.After that,the MicroLogix 1400 PLC can communicate with ControlLogix PLC,thereby achieving the data exchange between ControlLogix PLC and Quantum PLC.It enables the information sharing and equipment interconnection between the two sets of coal handling control systems.After three years of actual operation,it shows that the intercommunication network has features of fast response speed and accurate date reading,which greatly improves the reliability and production efficiency of coal handling system.