484 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 11 Program Control Instructions (JMP, LBL, JSR, RET, SBR, JXR, TND, MCR, UID, UIE, AFI, NOP, EOT, SFP, SFR, EVENT)
Example 2: The following example uses an EVENT instruction to initialize an event task.
(Another type of event normally triggers the event task.)
Continuous task
If Initialize_Task_1 = 1 then
The ONS instruction limits the execution of the EVENT instruction to one scan.
The EVENT instruction triggers an execution of Task_1 (event task).
Task_1 (event task)
The GSV instruction sets Task_Status (DINT tag) = Status attribute for the event task. In the Instance Name attribute, THIS
means the TASK object for the task that the instruction is in (that is, Task_1).
If Task_Status.0 = 1 then an EVENT instruction triggered the event task (that is, when the continuous task executes its EVENT
instruction to initialize the event task).
The RES instruction resets a counter that the event task uses.
The controller does not clear the bits of the Status attribute once they are set. To use a bit for new status information, you must
manually clear the bit.
If Task_Status.0 = 1 then clear that bit.
The OTU instruction sets Task_Status.0 = 0.
The SSV instruction sets the Status attribute of THIS task (Task_1) = Task_Status. This includes the cleared bit.
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