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Changes from Previous Products Section 9-5
Note The number of words that can be read and written per frame (i.e., the text
lengths) when using C-mode commands is different for C-series Modbus-RTU
Slave Units and CS/CJ-series Serial Communications Boards/Units. A host
computer program previously used for C-series Modbus-RTU Slave Units may
not function correctly if used for CS/CJ-series PLCs. Check the host computer
program before using it and make any corrections required to handle different
frame text lengths. Refer to the CS/CJ-series Communications Commands
Reference Manual (W342) for details.
9-5-2 RS-422A/485 Ports
Take the following differences into consideration when changing from an exist-
ing Modbus-RTU Slave System to one using an RS-422A/485 port on a CS/
CJ-series Serial Communications Board (CS1W-SCB41-V1 port 2 or CJ1W-
SCU41 port 1).
Note For pre-Ver. 1.2 Units, the number of words that can be read and written per
frame (i.e., the text lengths) when using C-mode commands is different for C-
series Modbus-RTU Slave Units and CS/CJ-series Serial Communications
Boards/Units. A host computer program previously used for C-series Modbus-
RTU Slave Units may not function correctly if it is used in CS/CJ-series PLCs.
When using Serial Communications Boards/Units with Unit Ver. 1.2 or later,
these programs can be reused by setting the Modbus-RTU Slave compatible
device mode to mode C (C500/120) or mode D (D200H). (Alternatively, check
the host computer program before using it and make any corrections required
to handle different frame text lengths. Refer to the CS/CJ-series Communica-
tions Commands Reference Manual (W342) for details.)
Previous
products
Model number Changes required for CS/CJ-series product
Wiring Other
C-series Modbus-
RTU Slave Units
3G2A5-LK201-E
C200H-LK202
3G2A6-LK202-E
Wiring pins have been
changed as shown below.
SDA: Pin 9 to pin 1
SDB: Pin 5 to pin 2
RDA: Pin 6 to pin 6
RDB: Pin 1 to pin 8
SG: Pin 3 to
Not connected
FG: Pin 7 to pin
Connector hood
It may be possible to use the host computer
programs without alteration as long as the
same communications settings (e.g., baud
rate) are used. It may be necessary, however,
to change programs to allow for different text
lengths in frames or different CS/CJ com-
mand specifications. (See note.)
C200HX/HG/HE
Communications
Board
C200HW-COM@@-E No changes have been made
in wiring.
It may be possible to use the host computer
programs without alteration as long as the
same communications settings (e.g., baud
rate) are used. It may be necessary, however,
to change programs to allow for different CS/
CJ command specifications.
CVM1 or CV-
series CPU Units
CVM1/CV-CPU@@ No changes have been made
in wiring.
It may be possible to use the host computer
programs without alteration as long as the
same communications settings (e.g., baud
rate) are used. It may be necessary, however,
to change programs to allow for different CS/
CJ command specifications.
CVM1 or CV-
series Modbus-
RTU Slave Unit
CV500-LK201