Table of Contents
Advertisement
2.3
Scan Time Structure
A CPU module sequentially performs the following processing in the RUN status. Scan time is the time required for all
processing and executions to be performed.
2.3.1
Initial processing
The CPU module performs preprocessing required for program operations. The preprocessing is executed only once
when any of the operations described in the following table is performed to the CPU module. When initial processing is
completed, the CPU module is placed in the operation status set by the switch. ( Page 48, Section 2.4)
Initial processing item
The I/O module initialization
Boot from an SD memory card
PLC parameter check
Initialization of devices outside the latch range (bit device: off, word
device: 0)
Automatic I/O number assignment to connected modules
CC-Link IE Field Network information setting
Intelligent function modules switch setting
CC-Link information setting
Ethernet information setting
Initial device value setting
*1
The operation indicates that the status is changed back to RUN without resetting the module after any program or
parameter was changed in the STOP status. (The switch is set from STOP to RUN (the RUN LED will flash), then back
to STOP and to RUN again.)
Note that the PLS, P instruction (instruction for pulse conversion) may not be executed properly with the above
operation. This is because the previous information may not be inherited depending on the program changes.
Power-on or reset
( Page 45, Section 2.3.1)
Initial processing
( Page 46, Section 2.3.2)
Refresh processing
( Page 46, Section 2.3.3)
Program operation
( Page 47, Section 2.3.4)
END processing
Powered-on
CHAPTER 2 APPLICATION OF PROGRAMMING
: Performed, : Not performed
CPU module status
Changed from STOP to
Reset
RUN
2
*1
45
Hide quick links:
Advertisement
Table of Contents
