C#与PLC通信程序.doc

,.DllImport(w95_s7.dll)private extern static int load_tool(byte nr, string device, byte, adr_table);对“打开PLC连接函数”进行简单的C#封装后代码如下：/*/ 建立连接，同一个连接只容许调用一次/ / 连接号connNo为1-4/ 连接参数,PLCConnParam定义的参数结构体/ 返回10进制错误号，0表示没有错误public static int Open(byte connNo, PLCConnParam connParam) int PLCCPUCnt = connParam.Length;if (PLCCPUCnt = 0) /传递参数不正确 return -1; byte, btr = new bytePLCCPUCnt + 1, 4; /多分配1个,用于存放0作为连接结束标记/转换连接表for (int i = 0; i connParam.Length; i+) btri, 0 = connParami.Addres; btri, 1 = 0; btri, 2 = connParami.Slot; btri, 3 = connParami.Rack; btrconnParam.Length, 0 = 0; btrconnParam.Length, 1 = 0; btrconnParam.Length, 2 = 0; btrconnParam.Length, 3 = 0; /调用初始化函数,打开连接int errCode = load_tool(connNo, S7ONLINE, btr);return errCode; public struct PLCConnParam public byte Addres; / 定义CPU的MPI/DP地址/public byte SegmentId; / 保留为0 public byte Rack; / 定义CPU的机架号public byte Slot; / 定义CPU的槽号 public enum PLCBlockType I = 1, /Input bytesQ = 2, /Output bytes M = 3, /Flag bytes T = 4, /Timer words Z = 5, /Counter words D = 6, /Data from DB DllImport(w95_s7.dll)private extern static int load_tool(byte nr, string device, byte, adr_table);/ / / / / public static int Open(byte connNo, PLCConnParam connParam)int PLCCPUCnt = connParam.Length;if (PLCCPUCnt = 0) return -1 byte, btr = new bytePLCCPUCnt + 1, 4 for (int i = 0; i connParam.Length; i+) btri, 0 = connParami.Addres; btri, 1 = 0; btri, 2 = connParami.Slot; btri, 3 = connParami.Rack; btrconnParam.Length, 0 = 0; btrconnParam.Length, 1 = 0; btrconnParam.Length, 2 = 0; btrconnParam