Omron SYSMAC CJ1W-SCU21-V1 - Modbus-RTU Slave Function for Replacing Existing Plcs; Support for 1:1 Modbus-RTU Slave

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Modbus-RTU Slave Function for Replacing Existing PLCs Section 9-6
9-6 Modbus-RTU Slave Function for Replacing Existing PLCs
An enhanced Modbus-RTU Slave function is provided to enable reuse of host
computer programs created for the existing PLC. By selecting the 1:N/1:1
Modbus-RTU Slave protocol and the Modbus-RTU Slave compatible device
mode according to the existing PLC model, the Board/Unit’s Modbus-RTU
Slave functions can be fully compatible with the Modbus-RTU Slave of the
existing PLC.
9-6-1 Support for 1:1 Modbus-RTU Slave
Pre-Ver. 1.2 Units
The C200H-LK101/201/202, C500-LK101/201/103/203, and C120-LK101/
201/202 Modbus-RTU Slave Units for earlier C-series PLCs (C200H and
C500) enable selection of either 1:1 or 1:N Modbus-RTU Slaves. The CS/CJ-
series and later PLCs, however, only support 1:N Modbus-RTU Slaves.
Therefore, the host computer programs created using 1:1 Modbus-RTU Slave
protocol cannot be reused in CS/CJ-series PLCs.
Unit Ver. 1.2 or Later
Host computer programs for 1:1 Modbus-RTU Slaves that have been created
using a C200H/C1000H/C2000H PLC can also be used with CS/CJ-series
PLCs by selecting the 1:1 Modbus-RTU Slave protocol. The 1:N/1:1 Modbus-
RTU Slave setting in the Setup Area in the DM Area enable selection of 1:1
Modbus-RTU Slaves.
1:N/1:1 setting Details Supported PLCs Remarks
1:N protocol A Modbus-RTU Slave protocol
that enables a single host to
be connected to a single PLC
(1:1) or to multiple PLCs
(1:N).
In previous Boards/Units, only
the 1:N protocol was sup-
ported.
C Series
Built-in port:
SRM1, CPM1, CPM1A,
CQM1-CPU
@@, C200HS-
CPU
@@, C200HE/HG/HX-
CPU
@@, C200HW-COM@@
CS/CJ Series
Built-in port:
CS1G/H-CPU
@@H, CS1G/H-
CPU
@@-V1, CS1D-
CPU
@@H, CJ1G/H-
CPU
@@H, CJ1G/M-CPU@@
Earlier models (pre-Ver. 1.2):
CS1W-SCB21(-V1)/41(-V1),
CS1W-SCU21(-V1), CJ1W-
SCU21/41
The CS/CJ Series, C200HS/
HX/HG/HE(-Z), CPM
@, and
CQM1
@ Series all support
only 1:N Modbus-RTU Slaves
for the CPU Unit’s built-in port
and Modbus-RTU Slave Unit/
Serial Communications
Board.
The earlier Serial Communi-
cations Units/Boards support
only 1:N Modbus-RTU Slaves.
CVM1/CV Series
CVM1/CV-CPU
@@ CVM1
(built-in port), CV500-LK201
The CVM1/CV Series sup-
ports only 1:N Modbus-RTU
Slaves for the CPU Unit’s
built-in port and Modbus-RTU
Slave Unit/Serial Communica-
tions Unit/Board.
C Series
C500-LK101/201/103/203,
C120-LK101/201/202
The C-series Modbus-RTU
Slave Units shown here sup-
port both 1:1 protocol and 1:N
protocol.
C Series
C200H-LK101/201/202
1:1 protocol A Modbus-RTU Slave protocol
that enables a single host to
be connected to a single PLC
only.
C Series
C500-LK101/201/103/203,
C120-LK101/201/202
C Series
C200H-LK101/201/202