Interrupts, Interrupt events, Multiple interrupts – Yaskawa FSP Amplifier FlexWorks User Manual
Page 89: Interrupt response time, Interrupt, Events, Multiple

Operating the FSP Amplifier Using FlexWorks
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4.11. Interrupts
When an event for which an interrupt has been defined occurs,
program execution is postponed while the specified interrupt
service routine is executed. This allows the FSP Amplifier to react to
events regardless of when they occur. Typical interrupt events
include the onset of an emergency situation or changes in user
inputs or in user or system variables.
4.11.1. Interrupt
Events
Interrupt events can be either:
♦ External, such as a change in an input from one value to
another,
Or
♦ Internal, such as a variable value meeting a given condition.
4.11.2. Multiple
Interrupts
The FSP Amplifier provides for eight different interrupts to be
specified for a single program. Each interrupt is assigned an
identifying number from 0 to 7. The identifying number also assigns
priority, where:
♦ Interrupt 0 has the highest priority.
♦ Interrupt 7 has the lowest priority.
Only one interrupt can be assigned to each priority level.
If multiple interrupts occur simultaneously, the interrupt service
routines will be run, one at a time, in order of priority.
If, while an interrupt routine is being executed, a new interrupt of a
higher priority occurs, the program will exit the present interrupt
service routine and handle the higher priority interrupt service
routine. Once that service routine has been completed, the
program will continue handling the lower priority interrupt service
routine. Once all the required service routines have been executed,
the program will continue at the return point specified by the last
interrupt service routine completed.
4.11.3. Interrupt
Response
Time
The maximum response time to the highest priority interrupt is 2
ms. Each lower priority interrupt is handled only when all higher
priority interrupt service routines have been completed.