Balluff BKT 21M-002 Serie Handbuch Seite 4

Setting
Two different setting possibilities are available:
− Standard setting: Normal calibration procedure (factory
setting). Only dark-on switching can be implemented
with this setting.
− Fine detection setting: To be used only when the
standard setting does not achieve the desired results,
i.e., if the contrast differences are too slight. The fine
setting can also be used to implement both light-on and
dark-on switching.
Calibration procedure (Teach-in)
Standard setting: (for dark-on operation only)
In this configuration the sensor detects objects having a
lower light intensity than their background.
1. Position the target or mark.
2. Press the SET button until the bi-color LED turns off.
3. Release the SET button and wait for the LED to come
on green. The sensor is ready. The yellow LED comes
on as soon as the object or mark is detected and the
output is active.
Fine detection setting (light- or dark-on):
This mode allows finer contrast differences to be
distinguished.
The sensor automatically selects the correct method:
Light-on for objects or marks which are brighter than the
background, and dark-on for objects or marks which are
darker than the background.
1. Position the target or mark.
2. Hold the SET button down until the bi-color LED goes
out and then flashes green. Then release the SET
button.
3. Place the background in the beam path.
4. Hold down the SET button again until the bi-color LED
goes out. The sensor is ready. The yellow LED comes
on as soon as the object or mark is detected and the
output is active.
Technical Data
Optical data
Operating distance
Emitter type
Minimum light spot diameter
Electrical data
Operating voltage U
B
Rated operating voltage
Ripple
Rated operating current I
e
Leakage current I
r
Rated insulation voltage
Switching output
Voltage drop
Reverse polarity protected
19 mm ± 2 mm
White LED
(400-700 nm)
3.5 mm at 19 mm
10...30 V DC
24 V DC
max. 2 Vpp
100 mA
≤ 10 µA
75 V DC
PNP or NPN,
N.O. or N.C.
≤ 2 V
yes
Short circuit protected
Switching frequency f
Permissible load capacitance
Range setting
Protection class
Light-on/dark-on switching
Mechanical data
Connection type
Housing material
Active surface material
Vibration
Shock
Housing dimensions
Weight
Time data
On-delay
Off-delay
Ready delay
Displays
Ready/Error
Output function
Ambient data
Mechanical protection
Permissible ambient light
Utilization category
Ambient temperature
Approvals
Listed 81U2 IND.CONT.EQ. for
use in the secondary of a class
2 source of supply
yes
5 kHz
≤ 1000 nF
SET button or teach-in
input
2
Automatic using fine
calibration
M12, 4–pin connector
GD-Zn, nickel plated
Glass (anti-reflective)
55 Hz, 1 mm amplitude
30 g, 11 ms
50 x 42.5 x 15 mm
80 g
≤ 0.1 ms
≤ 0.1 ms
< 200 ms
Bi-color LED (green/red)
yellow LED
IP67
max. 10,000 Lux
DC 13
-25 ... 55 °C
Balluff GmbH
Schurwaldstrasse 9
73765 Neuhausen a.d.F.
Germany
Phone +49 (0) 71 58/1 73-0
Fax +49 (0) 71 58/50 10
E-Mail: balluff@balluff.de
www.balluff.com
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