Rockwell Automation 1789-L10_L30_L60 SoftLogix 5800 System User Manual User Manual

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Rockwell Automation Publication 1789-UM002J-EN-P - December 2012

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What is the SoftLogix System?

Chapter 2

Setting Task Priorities

Each task in the controller has a priority level. The controller uses the priority
level to determine which task to execute when multiple tasks are triggered. There
are 3 configurable priority levels for periodic tasks that range from 1…3, with 1
being the highest priority and 3 being the lowest priority. A higher priority task
will interrupt any lower priority task. The continuous task has the lowest priority
and is always interrupted by any periodic task.

The continuous-task dwell time determines how much time to allow for other
Windows programs, running at a normal priority, to execute. The dwell time is
the time between the end of the continuous task and the start of the next
execution of the continuous task. The dwell time does not affect periodic tasks.
Periodic tasks execute as scheduled, regardless of the dwell time. By default, the
dwell time is 10 ms. This setting has an impact on overall system performance,
see

Appendix E

.

Tasks Based on Other Events

The SoftLogix controller supports an additional Windows event trigger. This
trigger lets you monitor Windows events in Windows 2000 or Windows XP
operating systems so that applications outside of the SoftLogix controller can
cause a task within the SoftLogix controller to execute. For more information,
see

Chapter 7

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