Mitsubishi Electric MELSEC iQ-R C R12CCPU-V User Manual page 159

When CPU of which fixed cycle communication function is set to "Not Use" exists, setting the send area for
the fixed cycle communication area to a CPU with the fixed cycle communication function set to "Not Use"
(that is, unset) with the host CPU parameter setting will result in no error since the unset CPU is regarded as
a reserved CPU for future setting.
Example: When "Not Use" is set to "Fixed Scan Communication Function" for the CPU No.4
Perform fixed cycle Perform fixed cycle
communication.
Fixed cycle
communication area communication area
CPU No.1
(Host CPU)
Send area of
CPU No.1
Send area of
CPU No.2
(Receive area of CPU No.1)
Send area of
CPU No.3
(Receive area of CPU No.1)
Send area of
CPU No.4
(Receive area of CPU No.1)
Perform fixed cycle
communication. communication.
Fixed cycle Fixed cycle
communication area
CPU No.2 CPU No.3
(Other CPU) (Other CPU)
Send area of Send area of
CPU No.1 CPU No.1
Send area of Send area of
CPU No.2 CPU No.2
Send area of Send area of
CPU No.3 CPU No.3
Send area of Send area of
CPU No.4 CPU No.4
Do not perform fixed
cycle communication.
Fixed cycle
communication area
CPU No.4
(Other CPU)
Since the fixed cycle
communication setting is
disabled, data are not sent to
other CPUs although the area
is reserved. Data from other
CPUs are not received.
8 MULTIPLE CPU SYSTEM FUNCTIONS
8.4 Data Communication Between CPU Modules
8
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