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35 BASIC CONCEPT
35.7 Scan Configuration
35.7 Scan Configuration
This section describes scan configurations of the CPU modules in a system using the SIL2 Process CPU.
Tracking transfer is performed during the END processing. ( Page 622 Tracking Transfer)
For details on the scan configuration 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.
Both systems perform different processing.
: Performed, : Not performed
*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 652 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 647 Program Execution in Both Systems)
Processing Control system Standby system
Initial processing/initial processing (when switched to RUN)
I/O refresh
*1
Program operation
*2
Tracking transfer
END processing
Program operation
Tracking transfer
CPU module is
switched to RUN
Initial processing
(when switched to RUN)
I/O refresh
Scan
time
END processing
Tracking transfer
CPU module is
switched to RUN
Initial processing
(when switched to RUN)
I/O refresh
Scan
time
END processing
Sending tracking data
Reception completion of
tracking data
<Control system> <Standby system>
Operation of the program
executed in both systems
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