Rockwell Automation Logix5000 Controllers Tasks, Programs, and Routines Programming Manual - Manual (Page 63)

Manage event tasks Chapter 2
To trigger an event task based on conditions in your logic, use the EVENT
Instruction Only trigger.
Let an event trigger this task.
Let an EVENT instruction trigger the task.
No tag is required.
The EVENT Instruction Only trigger requires that you use a Trigger Event Task
(EVENT) instruction to trigger the task. You can use an EVENT instruction
from multiple points in your project. Each time the instruction runs, it triggers the
specified event task.
EVENT Instruction trigger
Rockwell Automation Publication 1756-PM005-EN-P - October 2014 63