A-101
Appendices
CP2E CPU Unit Software User’s Manual(W614)
A-3 Response Performance
App
A-3-2 Interrupt Response Time
z Interrupt Response Time for Input Interrupt Tasks
The interrupt response time for input interrupt tasks is the time taken from when a built-in input has
turned ON (or OFF) until the input interrupt task has actually been executed.
The length of the interrupt response time for input interrupt tasks depends on the total of the hard-
ware interrupt response time and software interrupt response time.
* The wait time occurs when there is competition with other interrupts. As a guideline, the wait time will be 0 to
3 ms.
Note Input interrupt tasks can be executed during execution of the user program, I/O refresh, peripheral servicing,
or overseeing. (Even if an instruction is being executed, execution of the instruction will be stopped to exe-
cute the interrupt task.)
The interrupt response time is not affected by the above processing operations during which the interrupt
inputs turns ON.
Input interrupts, however, are not executed during execution of other interrupt tasks even if the input interrupt
conditions are satisfied. Instead, the input interrupts are executed after the current interrupt task has com-
pleted execution and the software interrupt response time has elapsed.
The interrupt response time of input interrupt tasks is calculated as follows:
Interrupt response time = Input ON delay + Software interrupt response time
A-3-2 Interrupt Response Time
Item Interrupt response time Counter 0~5 interrupts
Hardware interrupt
response time
Upward differentiation: 50 µs −
Downward differentiation: 50 µs −
Software interrupt response
time
Minimum: 23 µs + Wait time* Minimum: 40 µs + Wait time*
Input ON delay
Inputs:
(Interrupt signal
acknowledged.):
Interrupt task
execution:
Software interrupt response time
Cyclic task execution (main
program):
Interrupt response
time for input
interrupt task
Ladder program
execution time
Return time
from input
interrupt task
Ready to acknowledge
next interrupt signal
The time from when execution of the input interrupt task is completed until
execution of the cyclic task is resumed is 11 μs.