Fixed Scan Communication Setting; Cpu Number-Based Data Assurance Setting - Mitsubishi Electric MELSEC iQ-R Series User Manual

15.3

Fixed Scan Communication Setting

Since this product cannot perform a fixed-cycle operation and respond with high-speed, it cannot operate in a cycle unit set in
the fixed scan interval setting. However, to use the fixed scan communication area, the interval for data transmission between
CPU modules must be set to unify the setting in all CPUs.
Fixed scan communication interval setting
To set the fixed scan communication interval, refer to the following:
Page 121 Fixed scan interval setting
15.4

CPU Number-Based Data Assurance Setting

This product does not support data assurance on a CPU basis using a system. However, data assurance must be set on a
CPU basis in a multiple CPU because the setting must be the same in all CPUs.
To assure data, refer to the following:
Page 122 Data assurance for accessing CPU buffer memory
In a multiple CPU system where the CPU-number based data assurance is enabled, the following operation is
performed:
• In the CPU buffer memory (excluding the fixed cycle communication area), the next data is not sent or
received until the data read completion notification is received from another CPU. The data send/receive
timing of CPU No.1 coincides with the update interval of a CPU module that takes the longest time among
the following: the scan time of a programmable controller CPU, the refresh cycle of a C Controller module,
and the refresh cycle of this product.
• This product notifies the completion of data read at the timing set in the refresh cycle setting of the fixed
cycle processing function. (Page 181 FIXED CYCLE PROCESSING FUNCTION)
CPU number-based data assurance setting
To assure the CPU number-based data, set "Enable" for "PLC Unit Data."
[System Parameter]  [Multiple CPU Setting]  [Communication Setting between CPUs]
Window
Displayed items
Item
PLC Unit Data
Description
Set the data 'Assure' (Notification of reading completed will be sent) or
'Not Assured' (Notification of reading completed will not be sent) in PLC
module.
Transmit read timing of PLC module to ensure operation of other
module.
MELSECWinCPU refresh function will not be able to ensure operation of
other module. When a configuration is multi-CPU with PLC, read timing
of other module is transmitted in case PLC does not transmit read timing
and PLC refresh operation is stopped.
Timing of MELSECWinCPU is sent to other module to match the timing
of periodic execution (Refresh cycle). The MELSECWinCPU can not
read and write , during the execution of matching periodic time (Refresh
cycle).
Setting range Default
• Disable(Not Disable(Not notified
notified the the reading
reading completion to other
completion to PLC)
other PLC)
• Enable(notify the
read completion
to other PLC)
15 MULTIPLE CPU SYSTEM FUNCTION
15.3 Fixed Scan Communication Setting
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