Enabling full duplex on USB-2COMi

The USB-2COMi is a USB to 2x (RS422/RS485) serial port device (www.easysync.co.uk). The lab has one that is used to control PT platforms in the LT. Full duplex I/O can be enabled as follows:

If you want to use it in full duplex ( 4-wire RS485 ) mode similar to the
attached drawing, configure the 20 pin header
 jumpers as follows -

 1-2 = connected if at the end of the cable, else unconnected.
 3-4 = unconnected
 5-6 = unconnected
 7-8 = unconnected
 9-10 = connected ( permanently enable TxD )
 11-12 = unconnected
 13-14 = connected ( permanently enable RxD )
 15-16 = unconnected
 17-18 = unconnected
 19-20 = connected ( permanently enable CTS )

 The DB9 pinout in this configution is
 Pin 1 = TXA
 Pin 2 = TXB
 Pin 3 = RXB
 Pin 4 = RXA
 Pin 5 = GND
 Pin 6 = n/c
 Pin 7 = n/c
 Pin 8 = n/c
 Pin 9 = n/c

The above assumes that you are the RS485 master. If you
are the RS485 slave then -

9-10 = unconnected
11-12 = connected ( auto enable TxD )