Scan Configuration - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

26.6

Scan Configuration

This section describes scan configurations of the CPU modules in a redundant system.
In a redundant system, tracking is performed during the END processing. ( Page 454 Tracking Transfer)
For details on other than tracking transfer, refer to Chapter 1. ( Page 38 Scan Configuration)
The following figure shows scan configurations of when both systems are started up simultaneously in the backup mode.
<Control system>
CPU module is
switched to RUN
Initial processing
(when switched to RUN)
I/O refresh
Program operation
Scan
time
END processing
Tracking transfer
Both systems perform different processing depending on the set operation mode.
: Performed, : Not performed
Processing
Initial processing/initial processing (when
switched to RUN)
I/O refresh
Program operation
Tracking transfer
END processing
*1 Only the input refresh is performed. Whether or not to perform the output refresh depends on "Standby System Output Setting" of "CPU
Parameter". ( Page 485 Redundant System Operation Setting)
*2 The program operation is not performed with the default setting. Programs are executed according to "Both Systems Program
Executions Setting" in "Program Setting" of "CPU Parameter". ( Page 479 Program Execution in Both Systems)
*3 This processing will not be performed when the operation mode is changed from the backup mode to the separate mode.
<Standby system>
Initial processing
(when switched to RUN)
Operation of the program
executed in both systems
Sending tracking data
Reception completion of
tracking data
Backup mode
Control system Standby system
 
*1
 
*2
 
 
 
CPU module is
switched to RUN
I/O refresh
Scan
time
END processing
Tracking transfer
Separate mode
Control system
*3





26.6 Scan Configuration
Standby system
*3





26 BASIC CONCEPT
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