9. Appendices
Vlinx MESR9xx Modbus Gateway
Page 54
Manual Documentation Number MESR9xx-4508m
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MESR902T-x Serial Port Pinouts
Terminal
RS-232
RS-422
RS-485
A RTS
TXA(-)
DATA-
B TD
TXB(+)
DATA+
C CTS
RXA(-) ---
D RD
RXB(+)
---
E GND GND GND
In the RS-422 mode, TX lines are outputs and RX lines are inputs. Connect the Modbus
gateway TXB(+) line to the RXB(+) line of the Modbus network, and the Modbus
gateway TXA(-) to the RXA(-) of the Modbus network.
Ground is signal ground and provides a common mode reference for the RS-422 Receiver
and Transmitters.