Mitsubishi Electric MELSEC iQ-R-R00CPU - Page 308

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16 MULTIPLE CPU SYSTEM FUNCTION
16.4 Data Communication Between CPU Modules
■Refresh using CPU buffer memory
At the END processing of the host CPU module, device data of the host CPU module is written to the refresh area within the
CPU buffer memory on the host CPU module. The data written to the refresh area is transferred to the device of another CPU
module at the END processing of another CPU module.
Ex.
When CPU No.1 refreshes 32 points (B0 to B1F) and CPU No.2 refreshes 32 points (B20 to B3F):
■Refresh using fixed scan communication areas
At the period specified in the fixed scan communication setting, the device data of the host CPU module is written to the
refresh area within the fixed scan communication area of the host CPU module. The data written to the refresh area is sent to
the refresh area within the fixed scan communication area of another CPU, which in turn reads the transferred data into the
device.
Ex.
When CPU No.1 refreshes 32 points (B0 to B1F) and CPU No.2 refreshes 32 points (B20 to B3F):
CPU No.1 CPU No.2
CPU buffer memory CPU buffer memory
Refresh area Refresh area
Write with END processing of CPU No.1 Write with END processing of CPU No.2
Read with END
processing of
CPU No.2
Read with END
processing of
CPU No.1
Device
B0 to B1F (for CPU No.1)
B20 to B3F (for CPU No.2)
Device
B0 to B1F (for CPU No.1)
B20 to B3F (for CPU No.2)
CPU No.1
CPU buffer memory
Fixed scan communication area of CPU No.1
Refresh area
Fixed scan communication area of CPU No.2
Refresh area
The data is written to the refresh area.
B20 to B3F (for CPU No.2)
The data is read from the refresh area.
B0 to B1F (for CPU No.1)
Device
CPU No.2
CPU buffer memory
Fixed scan communication area of CPU No.1
Refresh area
Fixed scan communication area of CPU No.2
Refresh area
The data is written to the refresh area.
B20 to B3F (for CPU No.2)
The data is read from the refresh area.
B0 to B1F (for CPU No.1)
Device
The data is sent to
CPU No.2.
The data is sent to
CPU No.1.