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Using a Scheduled Interrupt as a High-precision Timer (CJ1M Only) Section 6-5
6-5-2 Specifying a Reset Start with MSKS(690)
When CJ1M CPU Units are used and the MSKS(690) instruction is used to
start the scheduled interrupt, the internal timer can be reset before starting the
interrupt (this is called a reset start).
This method can be used to specify the time to the first interrupt without using
the CLI(691) instruction.
Scheduled interrupts are started by using the MSKS(690) instruction to set
the scheduled interrupt time (interval between two interrupts). After executing
the MSKS(690) instruction, however, the time required before the first sched-
uled interrupt task starts (first interrupt start time) is fixed only if the CLI(691)
instruction is specified. Therefore, CJ1M CPU Units provide an internal timer
reset start, allowing the time to the first interrupt to be set without using the
CLI(691) instruction.
MSKS(690) Instruction Operand (Only when Scheduled Interrupt Is Specified)
6-5-3 Reading the Internal Timer PV with MSKR(692)
CJ1M CPU Units allow reading the PV of the internal timer that measures the
scheduled interrupt time. The time is read from either the scheduled interrupt
start point or the previous scheduled interrupt point. The internal timer PV is
read by executing the MSKR(692) instruction. The unit of time depends on the
scheduled interrupt unit time setting in the PLC Setup, in the same way as for
the scheduled interrupt time.
MSKR(692) Operands (Only when Scheduled Interrupt Is Specified)
Operand Set value
N (Interrupt identi-
fier)
4: Scheduled interrupt 0, normal setting (internal timer not
reset)
5: Scheduled interrupt 1, normal setting (internal timer not
reset)
14: Scheduled interrupt 0, specifies reset start (CJ1M CPU
Units onlyÃ…j
15: Scheduled interrupt 1, specifies reset start (CJ1M CPU
Units onlyÃ…j
Operand Set value
N (Interrupt identifier) 4: Scheduled interrupt 0, reads scheduled interrupt time (set
value)
5: Scheduled interrupt 1, reads scheduled interrupt time (set
value)
14: Scheduled interrupt 0, reads internal timer PV (CJ1M
CPU Units onlyÃ…j
15: Scheduled interrupt 1, reads internal timer PV (CJ1M
CPU Units onlyÃ…j