problem with multiple serial ports

problem with multiple serial ports

• U_T_A

  I'm pretty sure you will need events and form from the code supplied it is difficult to see what iyou were doing before..
  
  Personally I would create a class for each port you want to communicate that encapsulates the port itself. I would also use events to communicate info back to your form. Create the ports and attach to the events you decare for each on the form and then connect and start sending and hopefully reciving.
  
  
  So each class would have a structure something like this
  
  
  public delegate void OnMessageRecieved(object sender, some data you want to pass.....);
  public event OnMessageRecieved MessageRecieved;
  
  public void Connect()
  {
  try
  {
  // Create new serial port on selected comm
  mPort = new SerialPort(mPortName, mBaudRate, mParity, mDataBits,mStopBits);
  
  // Add the event Handler
  mPort.DataReceived += new SerialDataReceivedEventHandler(OnDataReceived);
  
  // Open the port
  mMPS2000Port.Open();
  }
  catch (Exception exception)
  {
  // re - throw with more info
  throw new Exception("Cannot connect to " + mPortName, exception);
  }
  }
  
  private void OnDataReceived(object sender, SerialDataReceivedEventArgs received)
  {
  // Read all the data from the port
  string messageData = mPort.ReadExisting();
  
  // Concatenate with any existsing data --
  mMessage += messageData;
  
  // Check you have a complete message - you can't guarentee all info has been recieved.
  if (check for end of message)
  {
  
  // Do what you want to do with the message data......
  
  // Raise events back to the form
  if (this.MessageRecieved != null)
  {
  MessageRecieved(this, the message data);
  }
  
  // Clean the message buffer
  mMessage = "";
  }
  }
  
  public bool Send(string message)
  {
  // Create the return
  bool sent = false;
  
  Byte[] messageBytes = System.Text.Encoding.ASCII.GetBytes(message.ToCharArray());
  
  // Write the message onto the port
  mPort.Write(messageBytes, 0, messageBytes.Length);
  
  // set the sent flag
  sent = true;
  
  // return
  return sent;
  }
  
  
  

• RemcoJVG

  Having a quick scan I notice that your code does not make use of events and waits assuming one port is going to respond straight after the message which may not be the case. I always prefer to use events to manage communications and the lack of these, or alternatively threads, may mean the code can't flow as written.
  
  These may sound like silly questions, but...
  Have you tried without sending anything to VIN
  Have you tried running 2 copies with 1 talking to VIN the other to Headstock
  Have you definitiately got someting connected to the port you are talking on Opening the port does not require anything to be connected to it like other protocols (On numerous occasions I have started debugging only to realise that the port I connected to was not the one I though it was :) )
  
  You have a lot of debug info in there which could provide more detail as to what is going on, unless someone else can spot an obvious error.
  
  

• tizza2k

  Thanks for response. I have already tried VINcomport_DataReceived and Headstockcomport_DataReceived events but I had big problem with event not getting fired everytime.

  For you reference see this code which I have implemented before doing this.

  private void VINcomport_DataReceived(object sender, SerialDataReceivedEventArgs e)

  {

  this.Invoke(new EventHandler(Handle_VINcomport_DataReceived));

  }

  private void Handle_VINcomport_DataReceived(object sender, EventArgs e)

  {

  string VINPortResponse = VINcomport.ReadExisting();

  Log(LogMsgType.Incoming, "Data received from port: " + VINPortResponse);

  if (objVINPortStatus == VINPortStatus.LaunchCode)

  {

  string s1 = "\x1B" + "\x07" + "\x0D";

  VINcomport.Write(s1);

  Log(LogMsgType.Outgoing, "Launch code sent to comport: \n");

  objVINPortStatus = VINPortStatus.VINNumber;

  objWait.DisplayMessage = "Sending launch code to VIN controller...";

  objWait.Status = PortStatus.VINNumber;

  }

  else if (objVINPortStatus == VINPortStatus.VINNumber)

  {

  VINcomport.WriteLine(lblVIN.Text);

  Log(LogMsgType.Outgoing, "VIN Number sent to comport: " + lblVIN.Text + "\n");

  objVINPortStatus = VINPortStatus.Para1;

  objWait.DisplayMessage = "Sending VIN number to VIN controller...";

  objWait.Status = PortStatus.VINPara1;

  }

  else if (objVINPortStatus == VINPortStatus.Para1)

  {

  VINcomport.WriteLine(objItemmast[0].PARA_1);

  Log(LogMsgType.Outgoing, "Para - 1 sent to comport: " + objItemmast[0].PARA_1 + "\n");

  objVINPortStatus = VINPortStatus.Para2;

  objWait.DisplayMessage = "Sending parameter-1 to VIN controller...";

  objWait.Status = PortStatus.VINPara2;

  }

  else if (objVINPortStatus == VINPortStatus.Para2)

  {

  VINcomport.WriteLine(objItemmast[0].PARA_2);

  Log(LogMsgType.Outgoing, "Para - 2 sent to comport: " + objItemmast[0].PARA_2 + "\n");

  objVINPortStatus = VINPortStatus.Para3;

  objWait.DisplayMessage = "Sending parameter-2 to VIN controller...";

  objWait.Status = PortStatus.VINPara3;

  }

  else if (objVINPortStatus == VINPortStatus.Para3)

  {

  VINcomport.WriteLine(objItemmast[0].PARA_3);

  Log(LogMsgType.Outgoing, "Para - 3 sent to comport: " + objItemmast[0].PARA_3 + "\n");

  objVINPortStatus = VINPortStatus.Para4;

  objWait.DisplayMessage = "Sending parameter-3 to VIN controller...";

  objWait.Status = PortStatus.VINPara4;

  }

  else if (objVINPortStatus == VINPortStatus.Para4)

  {

  VINcomport.WriteLine(objItemmast[0].PARA_4);

  Log(LogMsgType.Outgoing, "Para - 4 sent to comport: " + objItemmast[0].PARA_4 + "\n");

  objVINPortStatus = VINPortStatus.Para5;

  objWait.DisplayMessage = "Sending parameter-4 to VIN controller...";

  objWait.Status = PortStatus.VINPara5;

  }

  else if (objVINPortStatus == VINPortStatus.Para5)

  {

  VINcomport.WriteLine(objItemmast[0].PARA_5);

  Log(LogMsgType.Outgoing, "Para - 5 sent to comport: " + objItemmast[0].PARA_5 + "\n");

  Log(LogMsgType.Outgoing, "------------------------------------------" + "\n");

  Log(LogMsgType.Outgoing, "VIN Stamping finish" + "\n");

  Log(LogMsgType.Outgoing, "------------------------------------------" + "\n");

  objVINPortStatus = VINPortStatus.None;

  objWait.DisplayMessage = "Sending parameter-5 to VIN controller...";

  objWait.Status = PortStatus.VINDone;

  }

  }

  In this case problem I got is that event gets fired for Program selection and then for VINNumber but after that event is not getting fired and my program didn't work any more.

  I have noticed that at a time only 1 device is able to respond to my current implementation. As I am able to communicate with VIN or Headstock but not both

  Tell me if you need more information...

  
  
  

• William Lowers

  Yes I can send data to 2nd port and receive from it if I connect one port to application and another to hyper terminal.

  I got some success and now I am able to send and receive data from both ports but not simultaneously. I have to Open first port and complete the cycle ot it first and close ot. Then I can open 2nd port and complete cycle for that.

  Important thing is I can not open both ports together....and process data together as I have told you that DataReceived event are not getting fired.

  
  
  

• c_shah

  Thanks for response. As I said in last message that I have tried attaching events to both serial ports. But as I said datareceived events are not getting fired everytime and that is why I have done code without datareceived events.

  I agree with you that I must create a separate class but this is test applicaiton which must run successfully, after that I will create separate class for each port as you suggested.

  FOCUS: Problem is that when I open both ports and send data to first port it is working fine and for 2nd port I am not receiving data. BytesToRead always show 0 ....

  If I open just 1 port and test single device everything working fine.... but when I try to open 2 ports and want to send data to then one by one ... first port response perfectly but 2nd port is not responsing.....

  Looking forward for your response

  
  
  

• osamaT

  
  I'm at a bit of a loss I'm afraid, so more questions...
  
  Are the message you send on the 2nd port deing recieved by the device
  Does this work fine if you have one port attached via your code and send/recieve to the other over hyper terminal
  
  Hopefully someone else might chip in with some other ideas.
  
  
• problem with multiple serial ports