Document Reference No.: ES_000011
ES-R-2x01-M RS232 to RS422 / RS485 Converter User Guide
Version draft
Clearance No.: ES#*
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©2009 EasySync Ltd.
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2.1.3
RS422/RS485 Interface Configuration
The RS422/485 connector is a 9-way D-Type plug (DE-9P) that provides connection to up to four
differential signal pairs.
DE-9P Pin
Name
Comments
1
TxD- (A)
2
TxD+ (B)
3
RxD+ (B)
Not used in two-wire mode
4
RxD- (A)
Not used in two-wire mode
5
GND (C)
6
RTS- (A)
Output. RS422 handshake
7
RTS+ (B)
Output. RS422 handshake
8
CTS+ (B)
Input. RS422 handshake
9
CTS- (A)
Input. RS422 handshake
Table 2.2 – RS422/RS485 DE-9P Pin-Out
The screw terminal block provides access to the first five signals on the RS422/485 connector.
Pin
Name
Comments
1
TxD- (A)
2
TxD+ (B)
3
RxD+ (B)
Not used in two-wire mode
4
RxD- (A)
Not used in two-wire mode
5
GND (C)
Table 2.3 – RS422/RS485 Screw Terminal Pin-Out
The internal Jumper JP1 provides seven possible link settings to set the function of the RS422/485
interface.
Preliminary