Chapter 4. CPU module
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4.4 Operation Modes
The CPU module operates in one of the four modes - the RUN, STOP, PAUSE and DEBUG mode.
The following describes the PLC operation processing in each operation mode.
4.4.1 RUN mode
In this mode, programs are normally operated.
1) Processing when the operation mode changes.
Initialization of data area is executed when the first scan starts.
(1) If the PLC is in the RUN mode when applying the power :
(2) If the operation mode has been changed into from the STOP mode into the RUN mode : the
initialization is executed complying with the restart mode set. (cold / warm)
(3) 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) Task 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
Mode condition at the start
If the operation mode is the RUN mode
when the power is applied
Execution of input refresh
Check on the effectiveness of the program and decision
on the possibility of the execution
Data area initialization complying with the restart mode
Execution of programs and task programs
Check on the normal operation of the loaded modules
and their mounting conditions
Processing the communications service or other
internal operations
Execution of output refresh
Is the operation mode changed?
Operation with the operation mode changed
Data area initialization complying with the restart
mode set
If the operation mode has been changed
from the STOP mode to the RUN mode
Changed into another mode
The RUN mode is maintained