1 RUNNING A PROGRAM
1.1 Scan Configuration
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I/O refresh
The module performs the following before starting program operation.
• ON/OFF data input from the input module/intelligent function module to the CPU module.
• ON/OFF data output from the CPU module to the output module/intelligent function module.
While constant scan is in progress, I/O refresh is performed after the waiting time for constant scan expires.
Program operation
According to the program settings, the module executes from step 0 through the END/FEND instruction for each program.
This program is referred to as a main routine program. A main routine program can be divided into subroutine programs. (
Page 66 Subroutine Program)
END processing
The CPU module performs the following processing.
• Network module link refresh
• Link refresh of CC-Link IE Field Network Basic
• Intelligent function module refresh
• Instruction end processing (including dedicated instruction for the module)
• Device latch processing
• The device latch processing is a kind of service processing such as read and write of devices, labels, and program access
files ( Page 937 Target List and Operation Details of the Device/Label Access Service Processing Setting).
• Watchdog timer reset ( Page 125 Watchdog timer reset)
• Refresh between CPU modules (for the multiple CPU system configuration)
• Device/label collection by the data logging function (when the collection interval is set to "Each scanning cycle" or "Time
specification")
• Self-diagnostics processing
• Sets a value to the special relay/special register (for those with the set timing specified as the END processing timing)
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