I'm implementing a GUI in order to transmit a command to a device and to recive feedback from it. Even if I have no device connected on the serial port, when I transmit data I get back the same data I've sent. That is, the SerialDataReceivedEventHandler is activated.
These are the serialPort.write() commands I use
......
serialPort1.Write("on\r");
Thread.Sleep(500);
serialPort1.Write("GL\r");
Thread.Sleep(500);
serialPort1.Write("of\r");
......
And this is the associated EventHandler
this.serialPort1.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(this.serialPort1_DataReceived);
After each write, serialPort1_DataReceived is activated and with a serialPort1.ReadLine()
I get the same data I have written to the serial port.
How is possible? It is like I'm sending data to myself. My PC has no device connected. When I connect the serial port to the device, I get back the real answer.