Interrupt Tasks - Omron CJ2 CPU UNIT SOFTWARE User Manual

5 Understanding Programming
5-2-3

Interrupt Tasks

Interrupt tasks can be executed at any time in the cycle if any of the following conditions are in effect.
If an interrupt occurs, the interrupt task will be executed at any point in the cycle regardless of whether
the CPU Unit is currently executing an instruction in a cyclic task, refreshing I/O, or performing periph-
eral servicing.
Types of Interrupt Tasks
The following types of interrupt tasks can be used.
• Power OFF Interrupt Task
The power OFF interrupt task will be executed immediately before the power is turned OFF.
• Scheduled Interrupt Tasks
A scheduled interrupt task is used in programs that require scheduling execution of certain parts of
the user program, such as for monitoring the operation status at constant intervals.
• I/O Interrupt Tasks
An I/O interrupt task will be executed when an input to an Interrupt Input Unit connected to the CPU
Unit turns ON.
• External Interrupt Tasks
An external interrupt task will be executed when an interrupt is requested by an Special I/O Unit or
CPU Bus Unit.
• Input Interrupt Tasks (CJ2M CPU Units Only)
An input interrupt task will be executed when an input to a Pulse I/O Module connected to a CJ2M
CPU Unit turns ON.
• Extra Cyclic Tasks
Extra cyclic tasks are interrupt tasks treated as cyclic tasks. In this case, the purpose is not interrupt
processing, as is the case for other interrupt tasks, but to increase the number of cyclic tasks. Up to
128 cyclic tasks can be used. If extra cyclic tasks are used, however, up to 384 cyclic tasks can be
used.
5-20 CJ2 CPU Unit Software User's Manual