通过MODBUS TCP读写PLC数据源码.doc

通过MODBUS TCP读写PLC源码功能模块一：读写PLC主模块using System;using System.Net;using System.Net.Sockets;using System.Windows.Forms;/ / 通过modbus TCP读写PLC数据,/ / 设计:张东启,2011.4.9/ 2011.5.13更新,加入Application.DoEvents();以防连续读写时引起前台反应迟顿,同时让PLC有处理等待时间/ / / / public class PLCFunction public static bool Connected = false; public static int trytimes = 0; /内部使用变量 private static byte sendBuf = 0, 0, 0, 0, 0, 06, 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ; /共20个字节 private static byte recBuf = 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 ; /共20个字节 private static int hi, low, bytes, hi1, low1; private static Socket zdqSocket; private static string tiaoshi=N; private static string plcAddress = ; public static int ReadWord(int mwAddress) int rtValue = -99; if (init_plc() = 0) try hi = mwAddress / 256; low = mwAddress - hi * 256; sendBuf7 = 3; sendBuf8 = (byte)hi; sendBuf9 = (byte)low; sendBuf10 = 0; sendBuf11 = 1; /发送查询 zdqSocket.Send(sendBuf, 12, 0); Application.DoEvents(); bytes = zdqSocket.Receive(recBuf, 11, 0); /返回11个字节 if (bytes = 11) hi = recBuf9; low = recBuf10; rtValue = hi * 256 + low; trytimes = 0; catch (Exception te) if (tiaoshi = Y) MessageBox.Show(te.ToString(); trytimes+; return rtValue; public static void WriteWord(int mwAddress,int mwValue) if (init_plc() = 0) try hi = mwAddress / 256; low = mwAddress - hi * 256; hi1 = mwValue / 256; low1 = mwValue - hi * 256; sendBuf7 = 6; sendBuf8 = (byte)hi; sendBuf9 = (byte)low; sendBuf10 = (byte)hi1; sendBuf11 = (byte)low1; zdqSocket.Send(sendBuf, 12, 0); Application.DoEvents(); bytes = zdqSocket.Receive(recBuf, recBuf.Length, 0); /写一个字返回几个? trytimes = 0; catch (Exception te) if (tiaoshi = Y) MessageBox.Show(te.ToString(); trytimes+; public static int GetMemory(int mwAddress) int rtValue = -99; if (init_plc() = 0) try hi = mwAddress / 256; low = mwAddress - hi * 256; sendBuf7 = 2; sendBuf8 = (byte)hi; sendBuf9 = (byte)low; sendBuf10 = 0; sendBuf11 = 1; /发送查询 zdqSocket.Send(sendBuf, 12, 0); Application.DoEvents(); bytes = zdqSocket.Receive(recBuf, 10, 0); /返回11个字节 if (bytes = 10) hi = recBuf9; rtValue = hi; trytimes = 0; catch (Exception te) if (tiaoshi = Y) MessageBox.Show(te.ToString(); trytimes+; return rtValue; public static void SetMemory(int mwAddress,int mFlag) if (init_plc() = 0) /线圈置位与复位 int mBit = 0; if (mFlag = 1) mBit = 255; else mBit = 0; try hi = mwAddress / 256; low = mwAddress - hi * 256; sendBuf7 = 5; sendBuf8 = (byte)hi; sendBuf9 = (byte)low; sendBuf10 = (byte)mBit; sendBuf11 = 0; zdqSocket.Send(sendBuf, 12, 0); Application.DoEvents(); bytes = zdqSocket.Receive(recBuf, recBuf.Length, 0); trytimes = 0; catch (Exception te) if (tiaoshi = Y) MessageBox.Show(te.ToString(); trytimes+; private static int init_plc() /初始化 int zdqrt = 0; if (trytimes 3) /超过3次自动恢复连接 if (zdqSocket.Connected = true) zdqSocket.Disconnect(false); zdqSocket = null; trytimes = 0; try if (zdqSocket = null) zdqSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); zdqSocket.ReceiveTimeout = int.Parse(zdqpro.WriteOrReadINI(系统设置, 接收超时); plcAddress = zdqpro.WriteOrReadINI(系统设置, PLC地址); if (zdqSocket.Connected = false) /重新连接 tiaoshi = zdqpro.WriteOrReadINI(系统设置, PLC调试); zdqSocket.Connect(plcAddress, 502); catch (Exception te) if (tiaoshi = Y) MessageBox.Show(te.ToString(); trytimes+; zdqrt = -1; Connected = zdqSocket.Connected;/是否已经连接 Application.DoEvents(); return zdqrt; 读写配置文件功能代码 public static string WriteOrReadINI(string rootNod, string valueNod) /读取配置文件 XmlDocument mydoc = new XmlDocument(); mydoc.Load(zdqsys.ini); string str1 = rootNod + / + valueNod; string rt = mydoc.SelectSingleNode(str1).InnerText; return rt; public static void WriteOrReadINI(string rootNod, string valueNod, string valueStr) /写入配置文件 XmlDocument mydoc = new XmlDocument(); mydoc.Load(zdqsys.ini); string str1 = rootN