Mitsubishi Electric 700 Series Programming Manual page 68

Sequence program operation processing
Until execution of END instruction
Self-diagnostic checks
Updating of timer and counter present values
and on/off of their contacts
Fig 3.1 Operation Processings of Built-in PLC function
Power on
Initial processing
I/O initialization
Data memory initialization
Self-diagnostic checks
I/O refresh processing
Step 0
to
END processing
Overview
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