Task priorities allow control over the order that a task runs on a controller. A Logix controller is only capable of running a single task a time. When multiple tasks happen to occur at the same time, a task's priority setting will allow the controller to select which task it should run first. Within Logix controllers, there are 15 priority levels (except for SoftLogix, which only has 3). The lower the priority number, the higher the priority of the task. So, a task with a priority of 1 will have the highest priority, and a task with a priority of 15 will have the lowest priority.
The task's priority option is found in the Configuration tab of the Task Properties window, as in the following screenshot:
Now that we have covered the prioritization of tasks within RSLogix/Studio 5000, we are starting to understand the ways in which Rockwell controllers execute our code.
In the...