Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 737

Interrupt Control Instructions
Precautions
Examples
704
EI(694) does not require an execution condition. It is always executed with an
ON execution condition.
EI(694) cannot unmask input interrupts that have not been unmasked by
MSKS(690) or set scheduled interrupts that have not been set by MSKS(690).
EI(694) cannot be executed in an interrupt task.
In the following example, EI(694) enables all interrupt tasks that were disabled
by DI(693).
000000
Disables execution of all interrupt tasks.
Enables execution of all disabled
interrupt tasks.
Section 3-19