General Problem with RTS ?

[moelski]

Hi Roman,

I´m testing RS485 at the moment and its really strange with nrcomm and SerialPort (from .net).

Using this code:

Code Select Expand

        private void button1_Click(object sender, EventArgs e)
        {
            //nrComm1.SetStateRTS(false);
            byte[] buffer = new byte[] { 0x30, 0x31, 0x3E, 0x3F, 0x40, 0x41, 0x30 };
            nrComm1.Write(buffer, 0, buffer.Length);
            //nrComm1.SetStateRTS(true);
        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            //nrComm1.Protocol = StreamProtocol.None;
            //nrComm1.RS485Mode = true;
            nrComm1.Active = !nrComm1.Active;
            nrComm1.SetStateRTS(true);
        }

        private void checkBox2_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBox2.Checked)
                nrComm1.SetStateRTS(true);
            else
                nrComm1.SetStateRTS(false);
        }
I got only NUL in my Terminal.

If I send data from an "old" Delphi Terminal and control RTS by myself I got data transmitted over RS485.

But I can´t get it working with nrcomm (and also not woth SerialPort from .net).

There is one thing I really don´t understand, too...
If I switch the RTS line between set / reset I got a feedback in my listening terminal in BOTH cases.
No matter is RTS is set or not.  :P

Is there any general problem with controlling the RTS / DTR lines in .NET ?

Greetz Dominik

[moelski]

Hi Roman,

I put an Digital Multimeter to the RTS pin and it is always at 3,3v.
If I set or Reset RTS nothing happens to the Voltage !

So I think there is a general problem with setting and resetting RTS !

I doublechecked that with the normal .NET serialPort. Here it works. Set = 3,3V and reset = 0V. (At my USB/Serial Converter).
And an old Delphi Terminal is also able to set / reset RTS.
It must be a nrcomm Problem.

DTR is working fine.

[Roman Novgorodov]

Hello

Please try to use portmon or something like for monitor serial port changes.
Also please check that Protocol property is set in None.

Roman Novgorodov
DeepSoftware.Com

[moelski]

Ok setting and Resetting RTS is OK with 3.3.0.12  :)