No communication

Trying to communicate with an mBed microntroller (alike an Arduino).

In C# i need:
```
 this.serialPort1.DtrEnable = true;
 this.serialPort1.Handshake = System.IO.Ports.Handshake.RequestToSend;

```
to communicate.

In Hyperterminal it's simply setting the handshake to hardware.

I've tried all IntelliPort handshake options without success.
