Serial Port Drama

Have you tride the same command using Hyper Terminal?

well i am using different terminal software but it does work.

Try:

string received_data = Console.ReadLine();

instead of:

string received_data = sp.ReadLine();

Scrub my last try:

sp.WriteLine("ATI4\r\n");

Instead of:

sp.WriteLine("ATI4\r");

Hi,

Thanks for your response same result

Ward

Try to put this line

sp.WriteLine("ATE0\r");

before this one

sp.WriteLine("ATI4\r");

and see what happens

If the echo of your modem is enabled, i think is normal that you read "ATI4" instead of  "HDA CX11270 Soft Modem" because the modem sends you back what you write (in this case "ATI4\r") so when you use ReadLine method it retrieves the first line in the buffer and probably the next one could be what you are looking for
Use this command for disable the echo and try again:

ATE0

Hi,

Ok I have made some changes and got it more succesfully working, maybee I could get an explination.

Here is the output.


Data:
HDA CX11270 Soft Modem
OK
 Length: 30

Code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO.Ports;

namespace SerialTest1
{
    class Program
    {
        static void Main(string[] args)
        {

            SerialPort sp = new SerialPort();
            sp.BaudRate = 9600;
            sp.PortName = "COM3";
            sp.DataBits = 8;
            sp.StopBits = StopBits.One;
            sp.Parity = Parity.None;
            sp.Open();
            sp.WriteLine("ATI4\r");

            int bytes = sp.BytesToRead;
            string received_data = sp.ReadExisting();
            int length = received_data.Length;
            sp.Close();

            // I should get back:  HDA CX11270 Soft Modem
            // but instead I get back ATI4

            Console.WriteLine("Data: {0} Length: {1}", received_data,length);

            //Console.ReadKey();
        }
    }
}

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