Operation with special utility relays, Visual kv series – KEYENCE Visual KV Series User Manual
Page 263
4.6 Direct Clock Pulse Output
3-239
Visual KV
Series
1
4
Chapter 4 High-speed Counters
Calculating the pulse period and comparator preset value
The Visual KV PLC can output a maximum clock pulse of 50 kHz.
Use the following calculations to obtain the pulse period and preset value of the
high-speed counter comparator used to output the clock pulse.
■ Pulse period
Pulse period (µs) = 1,000,000 ÷ Frequency (Hz)
■ CTC preset value for pulses with 1:1 ON/OFF ratio (using one comparator)
CTC preset value = Pulse period (µs) ÷ Internal clock (µs) ÷ 2
■ CTC preset value for pulses with variable pulse width
CTC preset value for pulse width = Pulse width (µs) ÷ Internal clock (µs)
CTC preset value for pulse period = Pulse period (µs) ÷ Internal clock (µs)
■ Range of CTC preset value with the internal clock
Note 1: Set the CTC preset value to 10 or more when the operands for the high-
speed counter (CTH) is 2100 and 2200. The clock pulse output may be improper
when the preset value is set to less than 10.
Note 2: The pulse width may vary depending on the load connected to the circuit.
Be sure to determine the pulse width after monitoring actual output waveform with
an oscilloscope.
Note 3: When CTC0 and CTC1, or CTC2 and CTC3, are used to output the clock
pulse, do not specify the same value for the preset values of CTC0 and CTC1, or of
CTC2 and CTC3.
Operation with special utility relays
■ Operation with special utility relays for high-speed counter CTH0
The following table shows the ON/OFF status of output relay 0500 which can be
changed by setting special utility relays (2103 through 2112) at the start of opera-
tion, or by changing them during clock pulse output.
You can set desired values for the pulse period and pulse width, and can enable or
disable the direct output.
Operation of output relay 0500 when special utility relays are ON/OFF
OFF
ON
Pulse
width
Pulse period
OFF
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Pulse
width
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KVNKA Chap 04_2.p65
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