Allen-Bradley controllogix 1756-L55M12 User Manual page 81

Periodic Task
System Overhead
Continuous Task
0
Elapsed Time (ms)
System Overhead
Continuous Task
Elapsed Time (ms)
1 ms
System Overhead
Continuous Task
Elapsed Time (ms)
Periodic Task
System Overhead
Continuous Task
Elapsed Time (ms)
The interruption of a periodic task increases the elapsed time (clock
time) between the execution of system overhead functions.
1 ms
9 ms of Continuous Task Time
5
If you use the default time slice of 20%, the system overhead
interrupts the continuous task every 4 ms.
1 ms
4 ms 4 ms
5
If you increase the time slice to 50%, the system overhead interrupts
the continuous task every millisecond.
1 ms
5
If the controller only contains periodic tasks, the system overhead
time slice value has no effect. System overhead runs whenever a
periodic task is not running.
5
1 ms 1 ms
1 ms
9 ms of Continuous Task Time
10 15
1 ms 1 ms
4 ms
10 15
10 15
10 15
Publication 1756-UM001G-EN-P - January 2007
Develop Applications
1 ms
1 ms
20
1 ms
4 ms 4 ms
20
20
20
81
1 ms
25
1 ms
25
25
25