The (UIE) User Interrupt Enable instruction is used in conjunction with a (UID) User Interrupt Disable instruction. When enabled, the UID instruction prevents tasks with higher priority from interrupting the execution of the current task. The UIE instruction enables other tasks to interrupt the current task.
The task fault routine and the Controller fault handler are not disabled by the UID instruction.
Take caution; limit the amount of rungs placed between the UID and UIE instructions as a loss of communication may occur. In other words use only as needed.