Mitsubishi Electric MELSEC iQ-R Series User Manual page 83

In redundant mode
This section describes the scan configurations of the CPU modules in a redundant system.
In a redundant system, tracking transfer is performed in the END processing. ( Page 388 Tracking Transfer)
However, in a redundant system with redundant extension base unit, tracking transfer is performed before the program
operation. (The order of processing is reversed.)
The following are the scan configurations of the CPU modules when both systems are simultaneously started up in 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
Processing differs depending on the system (control system or standby system) and the operation mode (backup mode of
separate mode).
: Performed, : Not performed
Processing
Initial processing (when powered on or 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 425 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 418 Program Execution in Both Systems)
*3 This processing is not performed when the operation mode is switched 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





8 RUNNING A PROGRAM
8.1 Scan Configuration
8
Standby system
*3





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