Visual kv series – KEYENCE Visual KV Series User Manual
Page 267
4.7 Examples of Direct Clock Pulse Output
3-243
Visual KV
Series
1
4
Chapter 4 High-speed Counters
0000
0000
2105
RES
2105
SET
0000
0000
RES
KEEP
2105
SET
Cording
Note :When the input enable relay for the high-speed counter is used to start/stop
the clock pulse, the response is delayed by a maximum of one scan when output
starts. Moreover, if the response is delayed by one scan when output stops, the
clock pulse stops but the output may remain ON.
■ Tips
•
Use special utility relay 2105 to control (enable/disable) the clock pulse output by
external inputs.
•
Use the SET-RES pair or KEEP instruction to turn special utility relay 2105 ON/
OFF.
•
With this setting, the clock pulse is always turned OFF when it starts as well as
stops.
•
When either of the following programs is added to the example on the previous
page, the clock pulse is output from 0500 only when 0000 is ON.
When SET-RES instructions are used
When KEEP instruction is used
To output a clock pulse of 1 ms (1 kHz)-period from output relay 0501
This section describes a programming example that will output a clock pulse with 1:1
ON/OFF ratio from output relay 0501 by using the high-speed counter (CTH1) and
high-speed counter comparator (CTC2).
■ Special utility relay setting
Set the special utility relay (2203 through 2212) according to the following table.
When outputting a pulse with 1:1 ON/OFF ratio, you can simplify the program by
using the reverse (toggle) output (2207: ON).
■ Internal clock and CTC2 preset value
Specify the internal clock and calculate the preset value of CTC2 for the clock.
CTC2 preset value = Pulse period (µs) ÷ Internal clock (µs) ÷ 2
Obtain the preset value of CTC2 by substituting 1 ms for the pulse period and 10 µs
for the internal clock (special utility relay 2201).
In this case, the preset value of CTC2 is "50".
Refer to the following table for the CTC2 preset value with other internal clocks.
Line No.
Instruction
Operand
Line No.
Instruction
Operand
0000
LD
2008
0008
CON
0001
SET
2103
0009
SET
2107
0002
CON
0010
CON
0003
RES
2104
0011
RES
CTH0
0004
CON
0012
LD
2002
0005
RES
2105
0013
CTH
0 2101
0006
CON
0014
CTC
0 #00050
0007
RES
2106
.
o
N
y
a
l
e
R
g
n
i
t
t
e
S
3
0
2
2
N
O
4
0
2
2
F
F
O
5
0
2
2
F
F
O
6
0
2
2
F
F
O
7
0
2
2
N
O
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