Mitsubishi Electric MELSEC iQ-F FX5 User Manual page 38

Processing of operations by the CPU module during switch operations
Processing of operations by the CPU module is as follows according to the RUN or STOP mode.
RUN/STOP status
RUNSTOP
STOPRUN
The CPU module performs the following processing regardless of RUN or STOP status or paused status.
• Refreshing of input/output modules
• Automatic refreshing of intelligent function modules
• Self-diagnostic processing
• Device/label access service processing
• Setting of values to special relays/special registers (set timing: when END processing is executed)
For this reason, the following operations can be performed even in the STOP status or paused status:
• Monitoring of I/O or test operations by the engineering tool
• Reading/writing from external device using SLMP
• N:N Network
• MODBUS RTU slave
2 PROCESSING OF OPERATIONS ACCORDING TO CPU MODULE OPERATION STATUS
36
Processing of operations by CPU module
Processing of operations
in sequence program
The program is executed up to
the END instruction and then
stops.
Program execution starts from
step 0.
External output
All output points turn OFF.
Operation results are output
after the PLC is run for the
duration of one scan.
Device memory
Other than Y
Latch devices are held, and
non-latch devices are cleared.
The states of device memories
immediately before the CPU
module entered the RUN mode
are held.
Note, however, that when
device initial values are set, the
device initial values are set.
Y
All output points turn OFF.
Operation results are output
after the PLC is run for the
duration of one scan.