Omron CJ - 08-2008 Operation Manual page 519

Computing the Cycle Time
(Interrupt Input Unit retrieval)
Interrupt task execution
Cycle execution task execution
(main program)
Scheduled Interrupt Tasks
External Interrupt Tasks
Power OFF Interrupt Tasks
Some I/O interrupts, however, are not executed during interrupt tasks even if
the I/O interrupt conditions are satisfied. Instead, the I/O interrupts are exe-
cuted in order of priority after the other interrupt task has completed execution
and the software interrupt response time (1 ms max.) has elapsed.
Input
Input ON delay time
I/O interrupt task
interrupt response time
The time from when the I/O interrupt task ladder program execution is
completed until the cycle execution task resumes execution is 60 µs.
The interrupt response time of scheduled interrupt tasks is the time taken
from after the scheduled time specified by the MSKS(690) instruction has
elapsed until the interrupt task has actually been executed.
The maximum interrupt response time for scheduled interrupt tasks is 0.1 ms.
Also, there a deviation of 50 µ s from the specified scheduled interrupt time
(minimum of 0.2 ms, for CJ1-H-R CPU Units) due to the time interval required
for actually starting the scheduled interrupt task.
Note Scheduled interrupt tasks can be executed (while an instruction is being exe-
cuted, or by stopping the execution of an instruction) during execution of the
user program, I/O refresh, peripheral servicing, or overseeing. The interrupt
response time is not affected by the scheduled time elapsing during any of the
above processing operations.
Some scheduled interrupts, however, are not executed during other interrupt
tasks even if the scheduled interrupt conditions are satisfied. Instead, the
scheduled interrupt is executed after the other interrupt task has completed
execution and the software interrupt response time (1 ms max.) has elapsed.
The interrupt response time for scheduled interrupt tasks is the software inter-
rupt response time (1 ms max.).
Scheduled interrupt task
The interrupt response time for external interrupt tasks differs depending on
the Unit (Special I/O Unit or CJ-series CPU Bus Unit) that is requesting the
external interrupt task of the CPU Unit and the type of service requested by
the interrupt. For details, refer to the appropriate operation manual for the Unit
being used.
Power OFF interrupt tasks are executed within 0.1 ms of the power being con-
firmed as OFF.
Software interrupt response time
Ladder program
execution time
Scheduled interrupt time
Internal timer
Software interrupt response time
Section 10-4
Ready for next
interrupt Input Unit retrieval
I/O interrupt task
reset time
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