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Chapter 5 Power Supply / CPU
5 -19
5.5 Operation Modes
The CPU operates in one of the four modes - RUN, STOP, PAUSE and DEBUG mode. The following describes ope
ration processing in each operation mode.
5.5.1 RUN Mode
In this mode, programs are normally operated.
1) Processing when the operation mode is changed.
Initialization of data area is executed when the first scan starts and The possibility of execution of the program
is decided with check on its effectiveness.
2) Operation processing contents
I/O Refresh and program operation are executed.
(1) Interrupt programs are executed with the detection of their start-up conditions.
(2) Normal or abnormal operation and mounting conditions of the loaded module are checked.
(3) Communications service or other internal operations are processed.
The first scan start in the RUN mode
Initialize data area according to the prese
t
restart mode.
Check the program and determine it can be
executed or not.
Execute input refresh
Execute programs and tasks
Check the availability of expansion units
Execute communication and internal service
Execute output refresh
Operation mode is changed?
No
Yes
Operate with new mode