Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 1405

Number of available blocks
Another CPU module access instructions use the system area in minimum units of blocks, each consisting of 16 words.
The following table lists the numbers of blocks available for another CPU module access instructions.
Number of CPU modules
2
3
4
The following figure shows how blocks are used in a multiple CPU system consisting of three CPU modules.
CPU No.1 system area
Data send area from CPU No.1 to CPU No.2 and No.3
299
Send area
(to CPU No.2)
blocks
299
Send area
blocks (to CPU No.3)
Data send area from CPU No.2 to CPU No.1 and No.3
299
Receive area
(from CPU No.2)
blocks
Data send area from CPU No.3 to CPU No.1 and No.2
299
Receive area
(from CPU No.3)
blocks
Maximum number of data points that can be read or written
The maximum number of data points that can be read or written by an instruction depends on the number of CPU modules in
a multiple CPU system configuration.
Number of CPU Maximum number of data points that can be read
modules
2 modules 8192 point
3 modules 4096 point
4 modules 2048 point
Number of blocks used by instructions
The number of blocks used by instructions depends on the number of read/write data points. The following table lists the
numbers of blocks used by instructions.
Reading/ Number of blocks
writing
Read Number of blocks used by instructions = (21 + number of
read data points)16
Write Number of blocks used by instructions = (19 + number of
write data points)16
Maximum number of blocks
599
299
199
CPU No.2 system area
Receive area
(from CPU No.1)
Send area
(to CPU No.1)
299
Send area
(to CPU No.3)
blocks
299
Receive area
(from CPU No.3)
blocks
Example
• When the number of read data points is 100
Number of blocks used by instructions = (21 + 100)16 = 7 [blocks]
• When the number of write data points is 100
Number of blocks used by instructions = (19 + 100)16 = 7 [blocks]
CPU No.3 system area
299
blocks
299
Receive area
(from CPU No.1)
blocks
299
blocks
299
Receive area
(from CPU No.2)
blocks
299
Send area
(to CPU No.1)
blocks
299
Send area
(to CPU No.2)
blocks
Maximum number of data points that can be written
8192 point
4096 point
2048 point
12 MULTIPLE CPU DEDICATED INSTRUCTIONS
12.1 Another CPU Module Access Instructions
12
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