Hardware
7
Doc No: UMAN\GWY-800-B\0706
REVISION 0
Pin
Name
Signal Level
Description
1.
TX+
RS422 / RS485
Differential Tr, also referred as TXA
2.
TXD
RS232
Transmit
3.
RXD
RS232 / CMOS
Receive
4.
RX+
RS422 / RS485
Differential R, also referred as RXA
5.
GND
-
Signal Ground common to all signals.
6.
+5VDC
-
DO NOT USE
7.
TXD
CMOS
Transmit
8.
TX-
RS422 / RS485
Differential Transmit -, also referred as TXB
9.
RX-
RS422 / RS485
Differential Receive -, also referred as RXB
Pin Description for COM 1 / PLC 1
User can convert RS485 4 wire + Signal Ground system to a 2 Wire + Signal Ground system by shorting following
signals in the communication cable:
TX+
TX-
A
RX+
B
RX-
SG
SG
Note: If user has attached shield to Earth on Device end, leave the shield open on Gateway end. If user
has connected shield to Signal Ground on Device end, connect shield to Signal Ground on Gateway end.
A and B are polarity insensitive. Twisted pair cable should be used for Rs485 Network.
Upto 31 Devices can be multi-dropped on RS485 port of Gateway.