Modbus 和 C# -- 读取响应的问题
我是 modbus 的新手,需要一些帮助。我正在尝试使用 modbus 和串行通信进行连接。到目前为止,我设法发送数据,但无法收到任何数据。以下是我的代码。
构建数据包
private byte[] BuildPacket(int meter_address,int function,int table_name,int table_offset,int high_byte, int low_byte)
{
try
{
byte[] packet = new byte[6];
packet[0] = Convert.ToByte(meter_address);
packet[1] = Convert.ToByte(function);
packet[2] = Convert.ToByte(table_name);
packet[3] = Convert.ToByte(table_offset);
packet[4] = Convert.ToByte(high_byte);
packet[5] = Convert.ToByte(low_byte);
byte[] checksum = DoCheckSum(packet);
byte[] sendPacket = new byte[8];
sendPacket[0] = packet[0];
sendPacket[1] = packet[1];
sendPacket[2] = packet[2];
sendPacket[3] = packet[3];
sendPacket[4] = packet[4];
sendPacket[5] = packet[5];
sendPacket[6] = checksum[0];
sendPacket[7] = checksum[1];
return sendPacket;
}
catch (Exception)
{
throw;
}
}
modbus 的校验和
try
{
ushort CRCFull = 0xFFFF;
byte CRCHigh = 0xFF, CRCLow = 0xFF;
char CRCLSB;
for (int i = 0; i < (packet.Length); i++)
{
CRCFull = (ushort)(CRCFull ^ packet[i]);
for (int j = 0; j < 8; j++)
{
CRCLSB = (char)(CRCFull & 0x0001);
CRCFull = (ushort)((CRCFull >> 1) & 0x7FFF);
if (CRCLSB == 1)
CRCFull = (ushort)(CRCFull ^ 0xA001);
}
}
byte[] crcByte = new byte[2];
crcByte[1] = CRCHigh = (byte)((CRCFull >> 8) & 0xFF);
crcByte[0] = CRCLow = (byte)(CRCFull & 0xFF);
return crcByte;
}
catch (Exception ex)
{
throw ex;
}
}
通过串行和 modbus 连接
public void ConnectSerialModBus(string COM, int baud)
{
SerialPort port = new SerialPort(COM, baud, Parity.None, 8, StopBits.One);
if (!(port.IsOpen))
{
byte[] sendPacket = BuildPacket(3, 4, 11, 0, 1, 200);
port.Open();
port.RtsEnable = false;
port.Handshake = Handshake.None;
//SEND PACKET TO DEVICE
port.Write(sendPacket, 0, sendPacket.Length);
#region RECEIVE DATA FROM SERIAL
//MAKE PROCESS STOP FOR 5sec
Thread.Sleep(3000);
port.DiscardOutBuffer();
port.DiscardInBuffer();
port.RtsEnable = true;
int size = port.ReadBufferSize;
byte[] readingbyte = new byte[size];
port.Read(readingbyte, 0, readingbyte.Length);
string reading = Encoding.GetEncoding("Windows-1252").GetString(readingbyte);
port.Close();
port.Dispose();
#endregion
}
}
问题是在读取响应时,程序会卡住。如果可能的话请帮我找出问题所在。
I am a newbie to modbus and need some help. I am trying to connect using modbus and serial communication. so far i managed to send data but i am unable to get any. the following is my code.
Building packet
private byte[] BuildPacket(int meter_address,int function,int table_name,int table_offset,int high_byte, int low_byte)
{
try
{
byte[] packet = new byte[6];
packet[0] = Convert.ToByte(meter_address);
packet[1] = Convert.ToByte(function);
packet[2] = Convert.ToByte(table_name);
packet[3] = Convert.ToByte(table_offset);
packet[4] = Convert.ToByte(high_byte);
packet[5] = Convert.ToByte(low_byte);
byte[] checksum = DoCheckSum(packet);
byte[] sendPacket = new byte[8];
sendPacket[0] = packet[0];
sendPacket[1] = packet[1];
sendPacket[2] = packet[2];
sendPacket[3] = packet[3];
sendPacket[4] = packet[4];
sendPacket[5] = packet[5];
sendPacket[6] = checksum[0];
sendPacket[7] = checksum[1];
return sendPacket;
}
catch (Exception)
{
throw;
}
}
Checksum for modbus
try
{
ushort CRCFull = 0xFFFF;
byte CRCHigh = 0xFF, CRCLow = 0xFF;
char CRCLSB;
for (int i = 0; i < (packet.Length); i++)
{
CRCFull = (ushort)(CRCFull ^ packet[i]);
for (int j = 0; j < 8; j++)
{
CRCLSB = (char)(CRCFull & 0x0001);
CRCFull = (ushort)((CRCFull >> 1) & 0x7FFF);
if (CRCLSB == 1)
CRCFull = (ushort)(CRCFull ^ 0xA001);
}
}
byte[] crcByte = new byte[2];
crcByte[1] = CRCHigh = (byte)((CRCFull >> 8) & 0xFF);
crcByte[0] = CRCLow = (byte)(CRCFull & 0xFF);
return crcByte;
}
catch (Exception ex)
{
throw ex;
}
}
Connection through serial and modbus
public void ConnectSerialModBus(string COM, int baud)
{
SerialPort port = new SerialPort(COM, baud, Parity.None, 8, StopBits.One);
if (!(port.IsOpen))
{
byte[] sendPacket = BuildPacket(3, 4, 11, 0, 1, 200);
port.Open();
port.RtsEnable = false;
port.Handshake = Handshake.None;
//SEND PACKET TO DEVICE
port.Write(sendPacket, 0, sendPacket.Length);
#region RECEIVE DATA FROM SERIAL
//MAKE PROCESS STOP FOR 5sec
Thread.Sleep(3000);
port.DiscardOutBuffer();
port.DiscardInBuffer();
port.RtsEnable = true;
int size = port.ReadBufferSize;
byte[] readingbyte = new byte[size];
port.Read(readingbyte, 0, readingbyte.Length);
string reading = Encoding.GetEncoding("Windows-1252").GetString(readingbyte);
port.Close();
port.Dispose();
#endregion
}
}
The problem is when it comes to reading the response, the program gets stuck. if possible please help me out figure what is wrong with it.
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找到了问题的解决方案,问题出在thread.sleep上。给它 3 秒,这对于 rtf 接收数据包来说太长了。更改为 10ms 并且工作正常。
found a solution to the problem, the problem was with the thread.sleep. was giving it 3secs which is too much for the rtf to receive the packet. changed to 10ms and worked fine.