Omron CJ - 08-2008 - Page 714

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CJ1W-CIF11 RS-422A Converter Appendix G
RS-422A/485 Terminal Block
Block Diagram
DIP Switch Settings
Note 1. Set pins 2 and 3 to the same setting. (ON for the two-wire method or OFF for the four-wire method.)
2. To prohibit echoback, set pin 5 to ON (with RS control).
3. When connecting to several devices using the four-wire method in a 1:N connection, set pin 6 to ON
(with RS control). When connecting using the two-wire method, set pin 6 to ON (with RS control).
Signal
RDA–
RDB+
SDA–
SDB+
FG
SD
RS
CS
RD
ER
DR
SG (0 V)
FG
SW.6
SW.5
SW.2SW.3 SW.1
SDB(+)
SDA(-)
RDB(+)
RDA(-)
FG
+5 V
Pin
number
Function ON OFF
1 Terminating resistance With (at both ends of the commu-
nications path)
Without
2 Two-wire/four-wire method selec-
tion (See note 1.)
Two-wire method Four-wire method
3 Two-wire/four-wire method selec-
tion (See note 1.)
Two-wire method Four-wire method
4 Not used. --- ---
5 Selection of RS control for RD
(See note 2.)
With RS control Without RS control (always ready
to receive)
6 Selection of RS control for SD
(See note 3.)
With RS control Without RS control (always ready
to send)