Digi W R 2 1 manual Appendix a Serial 0 Port Pin-out Diagram, RS232, RS422/ RS485

Digi TransPort® WR21 Installation Guide

Appendix A: SERIAL 0 Port Pin-out Diagram

WWAN

SECONDARY

LAN 0 LAN 1

RS232

SERIAL 0

Pin 1

Pin 9

SERIAL 0

WWAN PRIMARY

9-30VDC

2A MAX

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/	Description
		RS485
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.

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