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Programming Appendix A
Processing Time
The time required from when the interrupt factor occurs until the interrupt task is called and the time required
from completing the interrupt task until program execution returns to the original position are shown below.
• Online Editing: If online editing is performed during operation, operation will be
stopped for a maximum of 65 ms, during which time interrupts
will be prohibited and the program will be overwritten.
• Data Exchange with Coordinator Module: Interrupts will be prohibited for 10
µs when data is exchanged
with the Coordinator Module.
• Analog I/O Refreshing: Interrupts will be prohibited for approximately 40
µs while analog
conversion is being performed for analog I/O.
• Hardware-supported Instructions: Some FQM1 ladder instructions are implemented using hard-
ware. Interrupts will be placed on standby during execution of
hardware-supported instructions that require time to process,
such as XFER(070) and BSET(071).
Interrupt Response Time Calculation Example
The interrupt response times from the interrupt input turning ON until the interrupt task is started for when an
input interrupt occurs under the following conditions are given below.
• No 1-ms timers are being used.
• No non-fatal errors occur or are cleared.
• Online editing is not performed.
Minimum Response Time
Interrupt input ON delay: 10
µs
Interrupt prohibition release time: 0
µs
+ Switchover time: 72
µs
Total: Minimum response time: 82 µs
Maximum Response Time
Interrupt input ON delay: 30
µs
Interrupt prohibition release time: 10
µs
+ Switchover time: 72
µs
Total: Minimum response time: 112 µs
Note (1) To return to the process being performed before the interrupt occurred, the execution time of the
interrupt task and 61
µs are required in addition to the above response time.
Item Description Time
1 Interrupt input ON delay This is the additional time required from when the interrupt input contact turns
ON until the interrupt is generated. This time applies only to input interrupts.
30 µs
↓
Interrupt condition established
↓
2 Waiting for interrupt pro-
hibition to be released
Time may be required to wait for interrupt prohibition to be released. See
below for details.
See below.
↓
3 Switchover time This is the time required to switch over to interrupt processing. 72 µs
↓
Interrupt processing routine executed
↓
4 Return This is the time from the END(001) in the interrupt task until returning to the
process that was being performed when the interrupt occurred.
61 µs