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Measurement of high-speed pulse
period
Example Checking rotation pulse period of engine
The sensor detects the mark on the jig for the engine and emits a pulse each rotation. Using these pulses, the
pulse period during engine rotation at high speed is measured
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Programming Technique
Step 1: The rotation pulse period is obtained by counting the number of internal clock
pulses emitted by the KV.
To obtain the rotation pulse period, internal clock pulses (example: 100µs period) emitted during each rotation pulse
period are counted using the high-speed counter.
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Step 2: Use the INT instruction for programming the first step operation.
Rotation pulses are received by the KV through input 0003, and the pulse period is measured using the Interrupt
instruction.
When an interrupt is executed, the current value of the high-speed counter is automatically transferred to the data
memory (DM1934) at the rising edge of the pulse received at input 0003.
When this function is used, the clock pulse count equals the difference between the value of the high-speed coun-
ter obtained at the rising edge of the first rotation pulse and that of the second rotation pulse.
INT
0003 |
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An interrupt is declared, and initialization is
performed. The interrupt polarity of input
0003 is set to the rising edge.
The difference between the current value
of CTH1 obtained at the rising edge of the
first rotation pulse and that obtained at the
rising edge of the second rotation pulse is
entered into DM0001.
The rotation pulses are received using the
INT instruction.
The rotation pulse period measured is
entered into DM0002 in milliseconds.
Internal clock pulses (100 µs) of the KV are
input into high-speed counter CTH1, and
counted.
Input time constant for input 0003 is set to
10 µs. |
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