ProSoft Technology 5202-DFNT-MCM4 - Manual (Page 44)

MCM ♦ ProLinx Gateway Communication Port Cables
Modbus Master/Slave Driver Manual
Page 44 of 80
ProSoft Technology, Inc.
October 16, 2009
5.5 Port 0, 1, 2, 3: RS-485 Interface Connections
The following illustration applies when the RS-485 interface is selected.
NOTE: This type of connection is commonly called a RS-485 half-duplex, 2-wire connection. If you
have RS-485 4-wire, full-duplex devices, they can be connected to the gateway's serial ports by
wiring together the TxD+and RxD+ from the two pins of the full-duplex device to Pin 1 on the
gateway and wiring together the TxD- and RxD- from the two pins of the full-duplex device to Pin 8
on the gateway. As an alternative, you could try setting the gateway to use the RS-422 interface
and and connect the full-duplex device according to the RS-422 wiring diagram (page 43). For
additional assistance, please contact ProSoft Technical Support.