RS-422 Connections
Manual Documentation Number: ESR90x-0508m
Appendix B
73
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B&B Electronics Ltd – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91-792444 – Fax +353 91-792445 – www.bb-europe.com
ESR901 Terminal Block Pin-out in RS-422 Mode
GN
D
CT
S/T
X-
TX
/TX
+
RX
/R
X+
RT
S/R
X-
1
2
3
4
5
Signal Name
RS-422
Direction
Terminal
Signal Ground
GND
---
1
Transmit Data (-)
TXD(-)
Out
2
Transmit Data (+)
TXD(+)
Out
3
Receive Data (+)
RXD(+)
In
4
Receive Data (-)
RXD(-)
In
5
Figure 52. ESR901 Terminal Block Pin-out in RS-232 Mode
In the RS-422 mode, TXD lines are outputs and RXD lines are inputs.
Connect the Serial Server TXDB(+) line to the RXDB(+) line of the serial
device, and the Serial Server TXDA(-) to the RXDA(-) of the serial device.
If Flow Control is set for RTS/CTS
, connect the Serial Server RTSB(+) to
CTSB(+) of the serial device and the Serial Server RTSA(-) line to the
CTSA(-) of the serial device. Connect from the Serial Server CTSB(+) line to
the RTSB(+) of the serial device and from the Serial Server CTSA(-) line to
the RTSB(+) line of the serial device.
If connecting to Receive Only
RS-422 devices, connect from the Serial
Server TXDB(+) and TXDA(-) lines to the receive pairs on all serial devices.
Ground is signal ground and provides a common mode reference for the RS-
422 Receiver and Transmitters.
