Open TPSAgent -> Serial ports tab:
It shows only available serial ports.
To activate serial port data input/output select Port Enabled check box in the port settings (Click to open... AggreGate Client button):
Set other settings and press OK.
Note that baud-rate speed more than 115200 and RS-485 support are still experimental.
To write data to serial port select Serial Port Output from the context menu of TPS Agent in AggreGate Client:
Choose port, enter the data and press OK:
Use AggreGate Client event log to see serial port data read/write debug:
Check out AggreGate documentation to use high level serial port communication.