Appendix a: serial 0 port pin-out diagram – Digi W R 2 1 User Manual
Page 19
Digi TransPort® WR21 Installation Guide
Page 19
Appendix A: SERIAL 0 Port Pin-out Diagram
WWAN
SECONDARY
SERIAL 0
9-30VDC
2A MAX
WWAN
PRIMARY
LAN 1
LAN 0
SERIAL 0
Pin 1
Pin 9
RS232
Pin #
Direction
RS232 DCE
Description
1
Out
DCD
Data Carrier Detect
2
Out
RXD
Receive Data
3
In
TXD
Transmit Data
4
In
DTR
Data Terminal Ready
5
N/A
GND
Ground
6
Out
DSR
Data Set Ready
7
In
RTS
Ready To Send
8
Out
CTS
Clear To Send
9
Out
RI
Ring Indicate
RS422/ RS485
Pin #
Direction
RS422/
RS485
Description
1
Out
CTS_B
Clear To Send B
2
Out
RD_A
Receive Data A
3
In
TD_A
Transmit Data A
4
In
RTS_B
Ready To Send B
5
N/A
GND
Ground
6
Out
RD_B
Receive Data B
7
In
RTS_A
Ready To Send A
8
Out
CTS_A
Clear To Send A
9
In
TD_B
Transmit B
Notes:
For true RS485 mode (2-wire half-duplex mode), the TD_A and RD_A pair and TD_B and RD_B pair should
be connected together.
The CTS and RTS signals for optional and not normally needed for RS485.