Mitsubishi Electric MELSEC iQ-R-R00CPU - Page 313

16 MULTIPLE CPU SYSTEM FUNCTION
16.4 Data Communication Between CPU Modules
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16
• When using an area within the fixed scan communication area
Data written to the area within the fixed scan communication area on the host CPU module using the write instruction is sent
to other CPU modules at the period specified in the fixed scan communication setting. Other CPU modules read the received
data using the read instruction. Unlike the refresh, data registered during the instruction execution can be directly read.
Ex.
When data written to the fixed scan communication area on the CPU No.1 using the write instruction is read by CPU No.2
using the read instruction:
1
2 3
D0
SM400
SM400
D100
1
2
3
CPU No.1
CPU No.2
CPU buffer memory CPU buffer memory
Fixed scan communication area of CPU No.1
Refresh area
Fixed scan communication area of CPU No.2
Execution of a write instruction
Write using a write instruction
The data is transferred
at multiple CPU
communication cycle.
The send data is
transferred to CPU
No.2.
Fixed scan communication area of CPU No.1
Refresh area
Refresh area
Refresh area
Fixed scan communication area of CPU No.2
Program
Read using a read instruction
Execution of a read instruction
Device
Fixed scan
communication area
Send data
of CPU No.1
U3E0\HG0
Program
Send program
Program
Send data
of CPU No.1
The data is transferred
at multiple CPU
communication cycle.
U3E0\HG0
Device
Fixed scan
communication area
MOV U3E0\HG0 D100
Receive program
CPU No.1 (programmable controller CPU) CPU No.2 (programmable controller CPU)
Program
MOV D0 U3E0\HG0