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6-2 Cycle Time
To aid in PC operation, the average cycle time can be displayed on the Pro-
gramming Console or any other Programming Device. Understanding the
operations that occur during the cycle and the elements that affect cycle time
is essential to effective programming and PC operations.
The overall flow of CPU operation is as shown in the following flowchart.
YES
NO
Power application
Clears IR area and
resets all timers
Checks I/O Unit
connections
Resets watchdog
timer
Checks hardware and
Program Memory
Check OK?
Resets watchdog timer
Services Peripheral
Devices
ERROR or ALARM
Sets error flags and
lights indicator
Executes program
Input and output
refreshing
ERROR
ALARM
Resets watchdog timer
Cycle time of PC
Cycle Time Section 6-2