To use serial communication is very useful to be able to send and receive data from the same COM port.
Unfortunately, this seems impossible with the current version of Modelica_DeviceDrivers, since the SW tries to open the same port twice.
See for example the following model (change txt into mo before using):
RXTXissue.txt
This comes from the choice to have separate serialPortSend and serialPortReceive, which both open (or try to open) their ports.
Maybe one should add a serialPortSendReceive with two connectors one to send, the other to receive?