12 CPU Unit Cycle Time
12-2 Computing the Cycle Time
12-2-1 CPU Unit Operation Flowchart
The CJ-series CPU Units process data in repeating cycles from the overseeing processing up to I/O
refreshing as shown in the following diagrams.
Sets error flags
ERR/ALM indicator ON
or Flashing?
12-4
Checks Unit
connection status.
Checks hardware and user
program memory.
No
Flashing
(non-fatal error)
Executes user program
(i.e., executes READY
cyclic tasks).
ON (fatal error)
End of program?
Resets watchdog timer and
waits until the set cycle
time has elapsed
Calculates cycle time.
Performs peripheral
servicing.
Performs I/O refreshing.
Power ON
Check OK?
Yes
No
Yes
CJ2 CPU Unit Software User's Manual