Serial Ports - Emerson FBxEdge User Manual

Emerson FBxEdge User Guide
D301913X012
October 2023
A.4.4

Serial Ports

The RXi2-BP provides two serial interfaces, one (P0) configured to RS-232 and one (P1)
configurable to RS-422 or RS-485 (2W/4W). The connector is a Phoenix Contact 1953745 or
equivalent and mates with a Phoenix Contact 1952296. Two mating plugs are shipped
with the unit. The RS-232 cable can be no longer than 15m. The RX-4xx cable can be more
than 30m, depending on capacitive cable load.
Figure A-8. Serial Ports
Signal Name Pin RS-232
TX
RTS
GND
CTS
RX
Signal Name Pin RS-4xx
RX+
RX–
GND
TX–
TX+
For RS–422 and RS–485-4-wire modes, connect the corresponding RX+/– signals with the
TX+/– signals and vice versa on the remote device. For RS–485 2-wire mode, connect RX+
and TX+ with the + line of the cable and the RX– and the TX– together with the – line of the
cable.
The TX/RX signal control is difference between the various RS–4xx modes. In the RS–422
mode, TX and RX are always active. In RS–485 4-wire mode, TX is active only when there is
something to transmit, while RX is always active. In RS–485 2-wire mode, TX and RX are
active when transmitting and inactive when not transmitting. Use the Operating System
device driver to select various modes.
A-6
Pin
1
2
3
4
5
Pin
6
7
8
9
10
Installing the RXi2-BP Gateway