C#汇川PLC通讯

1.下载汇川plc通讯API，然后下载文件，如下图：

解压上面下载的文件夹，在项目实例中找到两个动态链接库（ModbusTcpAPI.dll；StandardModbusApi.dll），如下图：

2.创建汇川PLC通讯测试项目，我用的VS2019软件，将上面的两个动态链接库（ModbusTcpAPI.dll；StandardModbusApi.dll）复制到创建的项目下，如图：

项目开发，UI界面如图：

通讯类SvMitsubishiEASY，代码如下：

    public class SvMitsubishiEASY 
    {
        #region //标准库
        [DllImport("StandardModbusApi.dll", EntryPoint = "Init_ETH_String", CallingConvention = CallingConvention.Cdecl)]
        //连接PLC
        public static extern bool Init_ETH_String(string sIpAddr, int nNetId = 0, int IpPort = 502);
        [DllImport("StandardModbusApi.dll", EntryPoint = "Exit_ETH", CallingConvention = CallingConvention.Cdecl)]
        //关闭连接
        public static extern bool Exit_ETH(int nNetId = 0);
        [DllImport("StandardModbusApi.dll", EntryPoint = "H5u_Write_Soft_Elem", CallingConvention = CallingConvention.Cdecl)]
        public static extern int H5u_Write_Soft_Elem(SoftElemType eType, int nStartAddr, int nCount, byte[] pValue, int nNetId = 0);
        [DllImport("StandardModbusApi.dll", EntryPoint = "H5u_Read_Soft_Elem", CallingConvention = CallingConvention.Cdecl)]
        public static extern int H5u_Read_Soft_Elem(SoftElemType eType, int nStartAddr, int nCount, byte[] pValue, int nNetId = 0);
        [DllImport("StandardModbusApi.dll", EntryPoint = "H5u_Read_Device_Block", CallingConvention = CallingConvention.Cdecl)]
        public static extern int H5u_Read_Device_Block(SoftElemType eType, int nStartAddr, int nCount, byte[] pValue, int nNetId = 0);
        [DllImport("StandardModbusApi.dll", EntryPoint = "H5u_Write_Device_Block", CallingConvention = CallingConvention.Cdecl)]
        public static extern int H5u_Write_Device_Block(SoftElemType eType, int nStartAddr, int nCount, byte[] pValue, int nNetId = 0);
        [DllImport("StandardModbusApi.dll", EntryPoint = "H3u_Read_Soft_Elem", CallingConvention = CallingConvention.Cdecl)]
        public static extern int H3u_Read_Soft_Elem(SoftElemType eType, int nStartAddr, int nCount, byte[] pValue, int nNetId = 0);
        [DllImport("StandardModbusApi.dll", EntryPoint = "H3u_Write_Soft_Elem", CallingConvention = CallingConvention.Cdecl)]
        public static extern int H3u_Write_Soft_Elem(SoftElemType eType, int nStartAddr, int nCount, byte[] pValue, int nNetId = 0);
        #endregion
        int nNetId = 1;
        public void Initial(string ip, int port)
        {                   
            bool result = Init_ETH_String(ip, nNetId, port);
            if (result == true)
            {
                MessageBox.Show("连接成功");
            }
            else
            {
                MessageBox.Show("连接失敗");
            }
        }
        public void Close()
        {
            bool result = Exit_ETH(nNetId);
            if (result == true)
            {               
                MessageBox.Show("关闭连接成功");
            }
            else
            {               
                MessageBox.Show("关闭连接失敗");
            }
        }
        public void ReadBlock16(string startAddress, ref short[] addressValues)
        {
            var addrType = startAddress.Substring(0, 1);
            var startAddr = Convert.ToInt32(startAddress.Substring(1, startAddress.Length - 1));
            byte[] pBuf = new byte[16000];
            int nCount = addressValues.Length;
            int nRet = H3u_Read_Soft_Elem(GetAddrTypeByte(addrType), startAddr, nCount, pBuf, nNetId);
            for (int i = 0; i  
实例调用代码：
 
public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        SvMitsubishiEASY PLC_EASY = new SvMitsubishiEASY();
        //连接PLC
        private void button1_Click(object sender, EventArgs e)
        {
            var ip = textBox1.Text.Trim();
            var port = Convert.ToInt32(textBox2.Text.Trim());
            PLC_EASY.Initial(ip, port);
        }
        //断开PLC连接
        private void button4_Click(object sender, EventArgs e)
        {
            PLC_EASY.Close();
        }
        //读取数据
        private void button2_Click(object sender, EventArgs e)
        {         
            var addrass = textBox3.Text.Trim();
            textBox4.Text=ReadSingle32(addrass).ToString();        
        }
        //写入数据
        private void button3_Click(object sender, EventArgs e)
        {          
            var addrass = textBox3.Text.Trim();
            var value = Convert.ToInt32(textBox4.Text.Trim());
            WriteSingle16(addrass, value);          
        }
        public int ReadSingle32(string address)
        {
            try
            {
                var temp = new short[2];
                PLC_EASY.ReadBlock16(address, ref temp);
                var tempByte = new List();
                tempByte.AddRange(BitConverter.GetBytes(temp[0]));
                tempByte.AddRange(BitConverter.GetBytes(temp[1]));            
                return BitConverter.ToInt32(tempByte.ToArray(), 0);
            }
            catch (Exception ex)
            {
                MessageBox.Show("PLC Read Fail:" + address);
                return -999;
            }
        }
        public bool WriteSingle16(string address, int value)
        {
            try
            {
                var temp = new short[] { (short)value };
                PLC_EASY.WriteBlock16(address, temp);
                return true;
            }
            catch (Exception ex)
            {
                MessageBox.Show("PLC Read Fail:" + address);
                return false;
            }
        }
    }
 
 
 
本篇文章主要介绍汇川PLC通讯开发实例，实例项目用的H3U系列通讯，目前只能读取写入整数，其他还未研究，可以读取写入X，Y，M，D，R码。