Rockwell Automation Logix5000 Controllers Tasks, Programs, and Routines Programming Manual - Manual (Page 66)

Chapter 2 Manage event tasks
Ladder Diagram in Program_B
If Shut_Down_Line = on (conditions require a shut down) then
run the Shut_Down task one time.
If you want your event task to run automatically, if the trigger fails to occur within
a certain time, assign a timeout value to the task. When the event task is finished,
the timeout timer begins to increment. If the timer reaches its preset value before
the event task is triggered, the event task runs automatically.
Description
Event task runs.
Timeout time stops incrementing.
Event task is done.
Timeout timer resets and begins incrementing.
Timeout timer reaches the timeout value.
Event task automatically runs.
In the Status attribute of the TASK object, bit 1 turns on.
Define a timeout value for
an event task
66 Rockwell Automation Publication 1756-PM005-EN-P - October 2014