Omron CJ1W-SCU32 Operation Manual page 254

7 Using Modbus-RTU Slave Mode
Additional Information
Addresses in Modbus data models start from 1, but addresses specified in Modbus-RTU com-
mands and addresses in the NJ-series CPU Unit start from 0. Refer to Allocation Areas for Coils,
Input Registers, and Holding Registers in 7-2 Device Variables for CJ-series Unit and System-
defined Variables (Modbus-RTU Slave Mode) for details on the I/O memory area addresses in
NJ-series PLCs that are allocated to Modbus data models (Coils, Input Registers, and Holding
Registers), addresses in Modbus data models, and addresses specified in Modbus-RTU com-
mands.
7-4 CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)