
B–61863E/15
11. INTERRUPT–TYPE
PMC FUNCTION
PMC SEQUENCE PROGRAM
407
The execution time of the interrupt program must be within about 6 ms,
even in the worst case.
If an interrupt program whose execution time is longer than 6 ms is
executed, or if too many interrupt requests are made, a PMC alarm (WN08
INTERRUPT LADDER TIME OVER) is issued.
The maximum execution time of the interrupt program can be checked
using the internal relay (R9022 to R9023).
D Internal relay R9022 to R9023 (interrupt program maximum
execution time)
R9022 Interrupt ladder program maximum execution time [10 µs]
This data is the maximum allowable execution time for the interrupt
ladder program. (0 to 655,350 µs)
D PMC alarm message (alarm screen)
Alarm message Meaning and response
WN08 INTERRUPT
LADDAR TIME OVER
The execution time of the interrupt ladder has ex-
ceeded the allowable value (about 6 ms). The
interrupt program is too large, or too many inter-
rupt requests were issued. So, the second level of
the ladder has operated.
(Response) Make the interrupt program smaller,
or reduce the number of interrupt requests.
CAUTION
Check the execution time of the interrupt program with the
internal relay mentioned above, and change the program to
keep the regular interrupt program execution time within 2
ms.
The WINDW machine instruction (with function code 10000) is used to
enable, disable, and clear (that is, nullify all internally stored requests for)
interrupts in the second–level program.
If an interrupt request arises when an interrupt has been disabled, interrupt
program execution is deferred until an interrupt is enabled.
The second–level program is initially in an interrupt disabled state. Any
interrupt request is rejected before the NC preparation completed signal
MA (F1.7) is input. To enable immediately when the power is applied,
execute the WINDW machine instruction (with function code 10000),
using the preparation completed signal MA (F1.7) signal. (See Section
11.4, “Sequence Program Examples.”)
D Window function (with function code 10000 for enabling, disabling,
and clearing interrupts)
[Description of data]
Interrupt–type PMC interrupts are enabled, disabled, and cleared.
11.3.4
Execution Time
11.3.5
Interrupt
Enable/Disable/Clear