B&B Electronics MESR321_SL_ML - Manual - Manual (Page 68)

Appendices Vlinx MESR321 Modbus Gateway
66
MESR321-xx_R001_2113_m
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MESR321 Serial Port Pinouts
Terminal RS-422 RS-485
A TDA (-) Data A (-)
B TDB (+) Data B (+)
C RDA (-) ---
D RDB (+) ---
E 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.