Can't connect to modem

[AlexMineware]

Hi,

I can use my modem through Hyperterminal and another 3rd party library. When I select my com port I get the error : Failed to communicate with phone. It is a D-LINK usb modem...

[alexmiby]

Same here, but there is a way to solve. Some modems answers are different so I found the following changes made the code working for me:
_connectedStream.Write(writeBuffer, 0, writeBuffer.Length); System.Threading.Thread.Sleep(100); // Add this line // read response
// read rows while (true) { readLength = _connectedStream.Read(readBuffer, 0, 512); System.Threading.Thread.Sleep(100); // Add this line if (readLength == 0) {

Amend this
WriteCommandExpectResponse("ATE=0", "ATE=0\r\rOK\r\0\rOK\r");
with this:
WriteCommandExpectResponse("ATE0", "ATE0\r\rOK\r\0\rOK\r");

Debug.WriteLine("Asking for storage enumeration"); string response = WriteCommandExpectResponse("AT+CPMS?", "\rOK\r"); string[] data = response.Split('\r'); if ((data[1].Length>=7 && data[1].Substring(0, 7).ToUpper() != "+CPMS: ") && (data[2].Length>=7 && data[2].Substring(0,7).ToUpper()!="+CPMS: ")) // line amended throw new UnexpectedResponseException("Phone message storages could not be enumerated");

// walk storages string[] storages = null; if (data[1].Length >= 7) storages = data[1].Substring(7).Split(','); // line amended if (data[2].Length >= 7) storages = data[2].Substring(7).Split(','); // line added

Also, message receiving still won't work with some mobile devices, they require different commands than the ones issued in the code.