A-3-2 Interrupt Response Time - Omron CP1E CPU UNIT SOFTWARE User Manual

Appendices
A-3-2 Interrupt Response Time
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.
Item
Hardware interrupt
response time
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
(Interrupt signal
acknowledged.):
Interrupt task
execution:
Cyclic task execution (main
program):
A-82
Interrupt response time
Upward differentiation: 50 µs
Downward differentiation: 50
µs
Minimum: 70 µs
Maximum: 160 µs + Wait
time*
Inputs:
Input ON delay
Software interrupt response time
Interrupt response
time for input
interrupt task
The time from when execution of the input interrupt task is completed until
execution of the cyclic task is resumed is 24 s.
Counter 0,1,2 interrupts
−
−
Minimum: 120 µs
Maximum: 230 µs + Wait
time*
Ladder program Return time
from input
execution time
interrupt task
CP1E CPU Unit Software User's Manual(W480)
Counter 3,4,5 interrupts
−
−
Minimum: 150 µs
Maximum: 670 µs + Wait
time*
Ready to acknowledge
next interrupt signal