Checklist for an axis registration task – Rockwell Automation Logix5000 Controllers Tasks, Programs, and Routines Programming Manual User Manual
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Manage event tasks Chapter 2
•
In the configuration of the event task, specify which registration input you
want to trigger the task. Choose either Axis Registration 1 or Axis
Registration 2.
•
You must first arm the registration input using a Motion Arm
Registration (MAR) instruction.
•
In the MAR instruction, the Trigger Condition operand defines which
transition of the registration input (Off → On or On → Off) triggers the
event task.
•
Once the registration input triggers the task, you have to re-arm the
registration input.
This timing diagram shows the relationship between the registration input and the
event task.
Checklist for an axis registration task
For This
Make Sure You
1. Registration input
Arm the registration input (MAR instruction). This lets the axis detect the registration input and trigger the event task.
•
Initially, arm the registration input to detect the first trigger condition.
•
Re-arm the registration input after each execution of the event task.
•
Re-arm the registration input fast enough to detect each trigger condition.
If your normal logic is
Then
Fast enough to re-arm the registration input between intervals of the
trigger condition
For example, normal logic always completes at least two scans
between registration inputs.
Arm the registration input within your normal logic, if desired.
Not fast enough to re-arm the registration input
Arm the registration input within the event task.
2. Task priority
Configure the event task as the highest priority task. If a periodic task has a higher priority, the event task is delayed until the periodic
task is finished.
3. Number of event tasks
Limit the number of event tasks. Each additional task reduces the processing time available for other tasks that could cause an overlap.
4. Automatic output processing
For an event task, you can typically disable automatic output processing (default). This reduces the elapsed time of the task.
Rockwell Automation Publication 1756-PM005-EN-P - October 2014
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