Kv -300 – KEYENCE Visual KV Series User Manual

Page 311

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6.2 High-speed Counters

KV

-300

KV-10/80

3-287

1

6

Chapter 6 Interrupts, High-speed Counters, Positioning Control

0000

2204

0000

SET

2204

RES

0000

2204

0000

SET

RES

KEEP

KEEP Instructions

SET/RES Instructions

When start/stop of clock pulse is controlled by the input relay which enables/
disables the high-speed counter, response relay of up to 1 scan is generated
at start. Also, the same response relay is generated at stop, which may stop
clock pulse output while the output relay is still ON.

This controls clock pulse so that it always starts and stops when 2204 turns OFF.
Turn ON/OFF special utility relay 2204 as required to enable or disable output of
direct clock pulses using one of the external clocks. Use SET and RES instructions
together or only KEEP instruction to turn ON/OFF this relay.
The diagram below can be added to the sample diagram so that direct clock pulses
are output through 0501 only when 0000 is ON.

CAUTION

Example of clock pulse with variable ON/OFF ratio

When outputting clock pulse with cycle 500 µs (2 kHz) and pulse width

200 µs from 0500

This program example shows how to output clock pulse varies ON/OFF ratio from
0500, through high-speed counter CTH0 and high-speed counter comparator
CTC0 and CTC1.

Setting special utility relays

Special utility relays 2103 to 2112 are set as shown in the table below.

Values set to the internal clock, CTC0 and CTC1

After the internal clock is determined, the CTC0 and CTC1 setting value is calcu-
lated from the following expression.
CTC1 setting value = Pulse width (µs) ÷ Internal clock (µs)
CTC0 setting value = Pulse cycle (µs) ÷ Internal clock (µs)
Assign 200 µs to pulse width, 500 µs to pulse cycle and 10 µs (2101: special utility
relay) to internal clock and calculate the CTC0 and CTC1 setting value.
The calculated results of CTC1 and CTC0 are "20" and "50", respectively.
Values calculated based on other internal clocks are listed below for your reference.

Special utility relay

Internal clock*

CTC0 value

CTC1 value

2100

1.0 µs

500

200

2101

10.0 µs

50

20

2102

100.0 µs

5

2

➮ * Refer to page 3-276.

Relay No.

Setting

Relay No.

Setting

2103

ON

2112

OFF

2104

OFF

2108

OFF

2105

OFF

2109

ON

2106

ON

2110

OFF

2107

OFF

2111

OFF

KVNKA Chap 06.p65

08.3.11, 0:10 PM

287

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