VESR424D Serial Server
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APPENDIX D: CONNECTOR PINOUTS
DB9M CONNNECTOR
DB9M Pin
RS-232
Direction (RS-232) RS-422/485 4-Wire RS-485 2-Wire
1
DCD
Input
RDA (-)
---
2
RD
Input
RDB (+)
---
3
TD
Output
TDB (+)
Data B (+)
4
DTR
Output
TDA (-)
Data A (-)
5
GND
---
GND
GND
6
DSR
Input
---
---
7
RTS
Output
---
---
8
CTS
Input
---
---
9
---
---
---
---
NOTE 1: In the RS-422 mode, TX lines are outputs and RX lines are inputs. Connect the serial server TXB(+) line to
the RXB(+) line of the serial device, and the serial server TXA(-) to the RXA(-) of the serial device.
NOTE 2: Ground is signal ground and provides a common mode reference for the RS-422 Receiver and Transmitters.
