Data Flow; Data Exchange With The Cpu Unit - Omron CJ Series Operation Manual

4 Data Exchange with the CPU Unit

4-1 Data Exchange with the CPU Unit
Data exchange between this Unit and the CPU Units uses the I/O port and memory for CJ-series Unit
allocated to the PROFIBUS Master Unit.
4-1-1

Data Flow

The CPU Unit and CJ-series PROFIBUS Master Unit exchange various types of information at each I/O
refresh via the memory for CJ-series Units within the CPU Unit.
From the user program, various types of information are exchanged using device variables and user-
defined variables. Device Variables are positioned internally in the CPU Bus Unit words allocated in
CIO and DM areas. User-defined variables are created by the user and can be allocated to specific
memory areas used for CJ-series Units allocated to slaves.
Access methods from
the user program
Device variable for CJ-
series Unit
User-defined variable
System-defined variable
Additional Information
By using these variables, the user can program without the need to be aware of the configuration
of the memory used for CJ-series Units.
4-2
AT specification
Data exchange timing
destination
I/O port During I/O refresh
Memory used for During I/O refresh
CJ-series Unit
At I/O refresh after instruction execution
None During I/O refresh
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
Unit data type
Software switch
Status
Slave area I/O data
Message send/receive data for
communications instructions
Unit Restart Flag, Communica-
tions Port Enabled Flags, etc.