问题
Hi I am trying to read the Serial Port Data. I used NModbus library for the modbus communication. Code works fine for read and write purpose. But sometimes i am having some unknown errors and i wanted to see the serial port activity. I tried using the SerialDataReceivedEventHandler but i am not getting anything from the port but still i am able to read the value of the holding registers. Here is my code. All i want to see the data packet being sent / received over the serial port.
namespace ModbusMaster
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.Load += Form1_Load;
}
void Form1_Load(object sender, EventArgs e)
{
int[] baud = new int[] {4800,9600,19200,38400,57600,115200};
int[] databit = new int[] { 7, 8 };
int[] stpBits = new int[] { 1, 2 };
string[] party = new string[] { "None", "Odd", "Even" };
string[] Mode = new string[] { "ASCII", "RTU" };
ModbusMode.DataSource = Mode;
Baud_Rate.DataSource = baud;
Data.DataSource = databit;
Stop.DataSource = stpBits;
Pari.DataSource = party;
GetPortList();
}
private void button1_Click(object sender, EventArgs e)
{
string ProtocolMode = ModbusMode.GetItemText(ModbusMode.SelectedItem);
string portName = listBox1.GetItemText(listBox1.SelectedItem);
if (listBox1.SelectedIndex == -1)
{
MessageBox.Show("Please select Serial Port!!!");
}
else
{
using ( SerialPort port = new SerialPort(portName))
{
if (port != null && port.IsOpen)
{
port.Close();
}
// configure serial port
port.BaudRate = int.Parse(Baud_Rate.Text);
port.DataBits = int.Parse(Data.Text);
port.Parity = (Parity)Enum.Parse(typeof(Parity), Pari.Text);
port.StopBits = (StopBits)Enum.Parse(typeof(StopBits), Stop.Text);
port.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);
port.Open();
// create modbus master
if (ProtocolMode == "RTU")
{
IModbusSerialMaster master = ModbusSerialMaster.CreateRtu(port);
int temp = ushort.Parse(StrtAdd.Text)- 1;
byte slaveId = byte.Parse(Slave.Text);
ushort startAddress = (ushort)(temp);
ushort points = ushort.Parse(regis.Text);
ushort[] holding_register = new ushort[] { };
holding_register = master.ReadHoldingRegisters(slaveId, startAddress, points);
string tempString = " ";
foreach (ushort value in holding_register)
{
tempString += value + " ";
}
val.Text = tempString;
// val.Text = Convert.ToString(holding_register[0] + " " + holding_register[1]);
}
if (ProtocolMode == "ASCII")
{
IModbusSerialMaster master = ModbusSerialMaster.CreateAscii(port);
int temp = ushort.Parse(StrtAdd.Text)- 1;
byte slaveId = byte.Parse(Slave.Text);
ushort startAddress = (ushort)(temp);
ushort points = ushort.Parse(regis.Text);
ushort[] holding_register = new ushort[] { };
holding_register = master.ReadHoldingRegisters(slaveId, startAddress, points);
string tempString = " ";
foreach (ushort value in holding_register)
{
tempString += value + " ";
}
}
}
}
}
private void port_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
// Show all the incoming data in the port's buffer
SerialPort sp = (SerialPort)sender;
string indata = sp.ReadExisting();
RcdPacket.Text = indata;
}
private void GetPortList()
{
listBox1.Items.Clear();
foreach (string item in System.IO.Ports.SerialPort.GetPortNames())
{
//store the each retrieved available prot names into the Listbox...
listBox1.Items.Add(item);
}
}
private void WriteData_Click(object sender, EventArgs e)
{
string ProtocolMode = ModbusMode.GetItemText(ModbusMode.SelectedItem);
string portName1 = listBox1.GetItemText(listBox1.SelectedItem);
if (listBox1.SelectedIndex == -1)
{
MessageBox.Show("Please select Serial Port!!!");
}
else
{
using (SerialPort port1 = new SerialPort(portName1))
{
if (port1 != null && port1.IsOpen)
{
port1.Close();
}
port1.BaudRate = int.Parse(Baud_Rate.Text);
port1.DataBits = int.Parse(Data.Text);
port1.Parity = (Parity)Enum.Parse(typeof(Parity), Pari.Text);
port1.StopBits = (StopBits)Enum.Parse(typeof(StopBits), Stop.Text);
if (ProtocolMode == "RTU")
{
port1.Open();
IModbusSerialMaster master1 = ModbusSerialMaster.CreateRtu(port1);
int temp = ushort.Parse(WriteAdd.Text) - 1;
byte slaveId = byte.Parse(SlvIdd.Text);
ushort startAdd = (ushort)(temp);
ushort WrValue = ushort.Parse(WriteVal.Text);
master1.WriteSingleRegister(slaveId, startAdd, WrValue);
}
if (ProtocolMode == "ASCII")
{
port1.Open();
IModbusSerialMaster master1 = ModbusSerialMaster.CreateAscii(port1);
int temp = ushort.Parse(WriteAdd.Text) - 1;
byte slaveId = byte.Parse(SlvIdd.Text);
ushort startAdd = (ushort)(temp);
ushort WrValue = ushort.Parse(WriteVal.Text);
master1.WriteSingleRegister(slaveId, startAdd, WrValue);
}
}
}
}
}
}
回答1:
If you just want to see the traffic that flows i recommend using Portmon from Sysinternals. This also guaranties that what you see is actually what was received on the port
来源：https://stackoverflow.com/questions/35142004/modbus-serial-port-data-reading-in-c-sharp