Omron CJ1W-SCU22, Руководство по эксплуатации, Страница: 82 / 478

2 Initial Settings and Allocations of Device Variable for CJ-series Unit
2-8
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
2-2 Data Exchange with the CPU Unit
Data exchange between this Unit and the CPU Units uses the I/O port allocated to the Serial Communi-
cations Unit or memory used for CJ-series Unit, if necessary.
For details on I/O ports, refer to 2-3 Device Variable for CJ-series Unit.
The CPU Unit and Serial Communications Unit exchange data as shown in the table and figure below.
Data exchange type
2-2-1 Data Flow
Access methods from
the user program
AT specification
destination
Data exchange timing Unit data type
Device variable for CJ-
series Unit I/O port (for Opera-
tion Data) During I/O refresh Software switch
Status
I/O port (for System
Settings data) When the power is
turned ON, the serial
communications port
setting is changed, or
the Unit is restarted System Settings data
User-defined variable Memory used for CJ-
series Unit During I/O refresh Data in holding registers and other
allocation areas in the Modbus-
RTU Slave Mode
At I/O refresh immedi-
ately after instruction
execution Send/receive data of Serial Com-
munications instructions, etc.
System-defined variable --- During I/O refresh Send/receive data of Serial Port I/O
instructions, etc.