Welotec OWLF Series User manual

User Manual
Laser Distance Sensor
User Manual
Laser Distance Sensor
OWLF series
Seite / Page 2
Contents 3snoitcurtsniytefaS.1
4noitcudortnI.2
5elpicnirplanoitcnuF.3
6snoitcurtsnignitnuoM.4
11stnihnoitacilppA.5
51e OWLFhtgnihcaeT.6
23tuptuomralA.7
33tupninoitazinorhcnyS.8
73atadlacinhceT.9
10. Connection diagram and pin assignment 40
14tpecnocgnidnuorG.11
24setonecivreS.21
34seirosseccA.31
44gnitoohselbuorT.41
Seite / Page 3
1 Safety instruction
Laser safety
•The laser diode installed in the OWLF emits visible red laser lights. This
laser belongs to the Class 2 laser standard specified by the IEC 60825-1
/ 2001. It also complies with 21 CFR 1040.10 and 1040.11 except for
deviation pursuant to laser notice No. 50, July 2001.
•Max. average output power < 1 mW
•Laser radiation, do not stare into beam
•To avoid uncontrolled laser exposure we recommended stopping the
beam with a matte object.
•For laser safety reasons, the voltage supply of the sensors must
be turned off when the whole system or the machine is turned off.
•Safety concept information and limiting parameters as published in
the sales documentation apply at all times.
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2 Introduction
The latest generation of laser distance sensors are setting new standards in terms of speed and
performance. The short response time (300…900µs) makes it possible to measure small and fast
moving objects up to 600 mm away and 0.3...2.7ms up to 1000 mm away. The advanced teach-in
function allows arbitrarily configuring the measuring range between the default limits in order to
increase the resolution. This allows the complete output swing of 4 – 20 mA and 0 – 10 V to be
mapped on the new range.
The alarm output switches on as soon as the sensor receives no usable signal or as soon as the
object is outside the measuring range.
The sync. output allows the sensor to synchronize the measurement or to use several sensors in a
non-synchronous mode when they would normally interfere optically or to synchronize sensors to a
machine clock or pulse.
The distance measurement is based on the triangulation principal. The use of a photodiode array as
the receiver and the intelligence of a high performance microcontroller produce measuring results
that are almost independent of object colors and just a very small linearity error in the analog output
signal.
The rugged sensor has a metal housing with a front cover made of glass. The 90° rotating connecter
allows wiring the sensor from the bottom or the rear .
Welotec GmbH
Zum Hagenbach 7 D-48366 Laer
www.welotec.com [e-mail]
Fon: +49 (0)2554/9130-00 Fax: [phone]

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3 Functional principle
The distance measured is based on the triangulation principle. The emitted laser beam falls on the
object as a small light spot and will be reflected diffusely. The position of the received light spot on
the receiver (a diode line) defines the receiving angle. This angle corresponds to the distance and is
the base for the internal calculations.
A distance change close to the sensor effects a large change in angle; the same distance change at
the end of the measuring range has a much smaller effect to the angle. This non-linearity feature is
linearized by the microcontroller. The analog output signal is linear to the distance.
The sensor adapts automaticallyto different object colors by varying the emitting laser intensity and
optimizing the exposure time. The result is a sensor that is nearly independent on different reflections
(different colors, shiny surfaces, dark objects). The sensor reaches its highest accuracy if the object
reflects diffusely.
Diode line with
receiving light spot
Object far away
Object closeto sensor
Seite / Page 6
4 Mounting instructions
•For a proper mounting, the mounting surface has to be flat. Be aware of the max. tightening
torque.
•In case of EMC, the sensor has to be grounded and a shielded cable has to be used.
•The 90° rotating connecter allows wiring the sensor from the bottom side or from the rear.
•The max. accuracy will be reached >15 minutes after power on.
Steps / edges:
When measuring right next to steps / edges, it is important that the receiving beam is not covered by
the steps / edges. This also appliesto depth measurements of holes or valleys.
Seite / Page 7
Mounting above shiny surfaces:
On shiny surfaces, it is important that no direct reflection can get to the receiving optics. The reflec-
tion could blind the sensor and produce poor results. To prevent this, the sensor may be slightly
tilted.
The direct reflection can be seen on a white piece of paper when held in front of the receiver.
Mounting above round, shiny surfaces:
Seite / Page 8
Objects with color edges in the same direction:
When color edges are orientated in the right direction, the effect to the measuring result will be minor.
If the color edges are in the wrong direction,the effect will depend on the reflectivity of the different
colors.
Shiny objects with a constant structure
Especially shiny objects with a constant structure (lathed or scuffed objects, extruded aluminum
profiles, etc.) could have a negative effect on the measuring result.
 

 
 
 


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Profile measurement:
For profile measurements, the sensor axes should be perpendicular to the moving direction.
Ambient light:
Be careful that no strong light source faces the receiving field.
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Several sensors without mutual opticalinterferences:
Several sensors, when mounted next to the other, can affect each other.When mounting a sensor,
be aware that no laser spotfrom another sensor is in the receiving field.
When mounted side by side (as shown in the picture in the middle), sensing distances up to 600 mm
can be achieved..
If it is not possible to mount the sensors the correct way, use the sync input and choose the asyn-
chronous function.
Measuring range
Measuring range
Measuring range
mutual optical
interfe
r
ences
Seite / Page 11
5 Application hints
To reach the maximum accuracy of OWLFxxx series laser distance sensors, keep an eye
on the following points:
Measuring on rough surfaces
All laser distance sensors are adjusted and linearized on a reference object. The object is a white
ceramic sheet with an absolutely flat surface. Many objects have a surface structure that is within the
resolution of the sensor or rougher. In such a case, the sensor with its small laser spot measures the
distance including the structure in contrastto a slide gauge that measures an average. For such
applications, we recommend to use a laser distance sensor with a laser line (OWLF 4xxx S1 L).
distance
max. min.
OWLF
Slide gauge
Flat surface
Rough surface !
Seite / Page 12
What can you do if you have color edges?
For a high accuracy measurement, it is necessary that the laser spot reflects constantly and diffusely.
Frequently, the object surface has different colors (black-white transition) or parts with different
reflectivity (marble plate).
If the laser spot falls just on a changing contrast (color edge), half of the spot will be reflected well
and the other part not so well. This produces a signal on the receiver that can not be analyzed
perfectly and causes a measuring fault.
Whole spot reflected with the
same reflectivity
accurate measurement
Spot on a color edge
measuring fault

 
  

 



Seite / Page 13
Often objects have several color edges on the surface.
for example:
In the field, you have no guarantee that the spot is not falling on just a color edge that can cause a
measuring fault.
Also, when the object moves, you may get an incorrect signal for each color edge (it appears that the
signal is unstable or has spikes)
In such cases, we suggest to move the object (or sensor), take several measurment values and
calculate the average. The quantity of measurment values depends on the structure, the moving
speed and the accuracy you desire.
Other possible solutions:
use a sensor with the laser line (OWLFxxxxS1 L)
contact Welotec
grooves
!
text
!
pictures !marble
!
rust
!
Measure
with
Laser Sensors
Seite / Page 14
What can you do if you have transparent, semi-transparent and highly reflective objects?
The measuring principle desires an object that reflects the light diffusely. Semi-transparent, transpar-
ent and highly reflective objects do not have this feature.
•When measuring on semi-transparent objects, the light enters the object and so the measured
distance is larger than the actual distance is.
•Light will pass through a transparent object so a measuring signal is not available.
•A highly reflective object only has a direct reflection and it is not possible to work with it. For such
an application, ask Welotec.
to measure these objects, it is only possible if you place a diffuse reflecting surface on the object
(sticker, etc.)
!
Semi transparent objects:
the light enters the object. the
measured distance is larger than the
real distance
Transparent objects:
The light passes the object
without a diff
use reflection.
No measurment is possible
Highly reflective objects:
Only direct reflection
No measurmentis possible
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6 Teaching the OWLF
Every sensor is delivered with the factory setup (max. measuring range). The teach-in feature was
designed to choose a smaller range within the nominal measuring range for optimizing the resolution
and linearity. Output current, voltage and alarm output adapt to the new range. Two positions must
be taught.
•The first teach-in position aligns with 0 V (or 4 mA), the second position aligns with 10 V (or 20
mA)
•These teach-in positions are always just at the border of the new range (inside the measuring
range)
•The sensor may be taught more than 10,000 times in its lifetime
•The sensor can always be reset to the factory settings
•The sensor may be taught with the teach button or via the external teach input
•During the teach-in process, the red LED and the alarm output provides a feedback
•The red LED on the back side of the sensor andthe alarm output indicate “run” mode if an ob-
ject is within the measuring range.
Attention:
Within 5 minutes after power on, the sensor can be taught via the button or the teach-in wire. After 5
minutes, the teach-in button will be locked preventing accidental adjustment. The teach-in wire is
active all the time.
Seite / Page 16
Example of a
taught measuring
range:
Example of a
reverse taught
measuring range:
m m 031m m 0 3
0V / 4mA
Analog out
10V / 20 mA
Example
of a taught
output
curve
Alarm out
LED
Standard output
curve
m m 031m m 0 3
0V / 4mA
Analog out
10V / 20mA
Example of
a reversed
output
curve
Alarm out
LED
Standard output
curve






 

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OWLF 4007 Fa S1 (L)
:rorreytiraenillacipyT:noituloserlacipyT
egnargnirusaemthguat=RMegnargnirusaemthguat=RM
Seite / Page 18
OWLF 4013 FA S1 (L)
:rorreytiraenillacipyT:noituloserlacipyT
egnargnirusaemthguat=RMegnargnirusaemthguat=RM
Seite / Page 19
OWLF 4030 FA S1 (L)
:rorreytiraenillacipyT:noituloserlacipyT
egnargnirusaemthguat=RMegnargnirusaemthguat=RM
Seite / Page 20
OWLF 4060 FA S1 (L)
:rorreytiraenillacipyT:noituloserlacipyT
egnargnirusaemthguat=RMegnargnirusaemthguat=RM

Seite / Page 21
OWLF 4100 FA S1 (L)
:rorreytiraenillacipyT:noituloserlacipyT
egnargnirusaemthguat=RMegnargnirusaemthguat=RM
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OWLF 4100 FS S1 (L)
:rorreytiraenillacipyT:noituloserlacipyT
egnargnirusaemthguat=RMegnargnirusaemthguat=RM
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6.1 How to teach a new range using the teach button
Teaching a new measuring range:
Within 5 minutes after power-up, the button may be used to teach a new range. After finishing a
teach procedure, the 5 minutes starts again. After the 5 minutes, the sensor does not respond to
pressing the button. Seven steps to teaching a new measuring range:
1. Press (and hold) the button. The red LED will turn on, if the sensor can be taught.
2. Hold down the button for 5 more sec. The LED will start to blink.
3. Release the button.
4. Place a target at the first new position of the measuring range. This is the position that will later
produce 0 V (or 4 mA).
5. Briefly press the button again. The LED will stop blinking and will stay on for about 3 sec to
indicate that the first position has been stored. Thenthe LED will blink again.
6. Now place the target at the second position (the other end of the new range), which will produce
10 V (or 20 mA).
7. Briefly press the button again. The LED will stop blinking and will stay on for about 3 sec to
indicate that the second position has been stored. The LED will then turn off and blink once
more. Now the sensor is ready to measure.
The new, smaller operating range is now set. The red LED now indicates whether an object is within
the new range (LED OFF) or not (LED ON)
If one of the new borders of the range was outside the standard range or the two positions were too
close to each other, then the new settings are not valid. The sensor will respond with an extended
blinking at the end of the teach procedure. The previous settings are still valid and the new settings
are lost.
Seite / Page 24
Timing of the teach procedure
LED is ON if the procedure
was successful
LED blinks if the procedure
was not successful
t1 t2 t3 t4
t5
t6
red LED


     
 

Seite / Page 25
6.2 How to reset the factory settings using the teach button
Within 5 minutes after power up, the button may be used to reset the sensor back to the factory
settings. After finishing a teach procedure,the 5 minutes starts again. After the 5 minutes, the sensor
does not respondto the button.
1. Push the button. The red LED will turn on, if the sensor can be taught.
2. Hold down the button further 5 sec. The LED will start to blink. DO NOT RELEASE the button
now. Wait another 10 sec until the LED is ON without blinking. Factory settings have been re-
stored to the sensor.
3. Release the button.
(t1
red LED
t12
Until button has been
released (t13)
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6.3 How to teach a new range using the external teach input
Teaching the sensor via the external teach input is equivalent tothe teaching procedure via the
button. There is no 5 min. time limit. The sensor may be taught at any time. In addition to the LED,
the alarm output is used to indicate the state of the sensor for an external digital controller.
red LED
t1 t2 t3 t4
0 V
12-28 V
Teach-in wire 9t8t7t
Alarm output
t6
t10
t5
Seite / Page 27
Delay between teach signal and response on alarm output:
Input circuit:
27kΩ
10kΩ
teach-in
low: 0 .. 2V
high: 12 .. 28V
3V3
t10 t11
alarm output
external teach
input
Seite / Page 28
6.4 How to reset the factory settings using the external teach input
Teaching the sensor via the external teach input is equivalent tothe teaching procedure via the
button. There is no 5 min. time limit. The sensor may be taught at any time. The alarm output can be
used as an acknowledge signal for a control system.
0 V
12-28 V
red LED
Alarm output
Teach-in wire
t1 t14
t15


  





Seite / Page 29
Delay between teach signal and response on alarm output:
t11
alarm output
external teach input
Seite / Page 30
Time Description of timing functions Value Comment
t1 Minimum button hold time to enter
teach mode 5 s
Using the button, this feature can
only be used within 5 minutes
after power-up. Using the external
teach input, it may be used at any
time.
t2 Maximum waiting time after
teaching the first position. < 20 s
If the button has not been pushed
during this interval, the sensor will
leave the teach mode without any
changes.
t3 LED on as response for the first
position. approx 3 s
t4
Maximum waiting time after
teaching the second position. < 20 s
If the button has not been pushed
during this interval, the sensor will
leave the teach mode without any
changes.
t5 LED on and “OK response” after
the second position. approx 3 s
t6
LED Blinking for “NOT OK
response” after teaching the
second position.
approx 5 s
t7
Minimal time between high/low
transition of alarm output high/low
transition of the external teach
input at the beginning of the teach.
1 ms
Seite / Page 31
t8 Pulse lengths on external teach
input for first position. 30 .. 2000 ms
t9 Pulse lengths on external teach
input for second position. 30 .. 2000 ms
t10
Delays between teach signal and
response on alarm output at the
rising edge of the signal.
< 20 ms
t11
Delay between teach signal and
response on alarm output at the
falling edge of the signal
< 10 ms
t12
Minimum blinking time for the
reset to factory settings with
button.
10 s
t13 Blinking time after reset to factory
settings > 0.2 s As long as the button is down or
the external teach input is high.
t14
Minimum blinking time for the
reset to factory settings with
externalteach input.
10 s
t15
Minimum high time of the external
teach input after the alarm output
has been set at the end of the
setting of the factory settings.
0.2 s
Seite / Page 32
7 Alarm output
The alarm output indicates when an object is outside the measuring range or when the received
signal cannot be used for measuring distance. In this case, the output shows 0 V (4 mA).
The sensor has no internal hold function if measured values are missing. It provides real time
measuring.
In some critical applications (poorly reflective objects), the sensor sometimes loses the signal and
the output signal drops down to 0 V (4 mA). For such applications, we recommendto use the alarm
output. Before reading the analog signal, observe the alarm output; if it is active, the analog signal
must be invalid.

Seite / Page 33
8 Synchronization input
Hold function of the analog output / switching off the laser diode
If 12-28 V is being applied to the sync input,then the sensor will hold the value of the current meas-
urement and will switch off the laser diode. It will wait until the sync input goes back to low (0 V)
before it starts a new measurement.
After every measuring cycle, the sensor will test the sync input again. After the high signal on the
synch. Input, it takes one cycle T1 until the hold situation is reached.
1TrosneS
OWLF 4007+ 4013 + 4030 + 4060 FA S1 (L) 0.9 ms
sm7.2OWLF 4100 FA S1 (L)
sm01OWLF 4100 FS S1 (L)
T1
Low/high edge of sync signal
synch signal
0V
12-28 V
Seite / Page 34
Synchronizing several sensors
Several sensors may be synchronized using an external clock. The clock cycle must be low for less
than T1. The total time of a cycle must be at least T2. Within 20 cycles all sensors will be synchro-
nized.
3T2T1TrosneS
10 ~ 250 µs >1000 µs 5 µs ~ 450 µs
sµ0081~sµ51sm3>sµ052~01
sm7~1.0sm5.01>sm3~10.0
If sensors are being synchronized this way, they all start their cycles at the same time. This means
they start to sample light together. The length of the sampling interval T3 or shutter time depends on
the surface. It may range from T3. White or gray objects reflect well enough to enable a less than half
the sampling of interval T3. Only very dark objects actually need the maximum sampling interval.
T1
T2
12-28V
0V
sync. signal
Seite / Page 35
Several sensors in non-synchronous use
To prevent a negative mutual influence, using several OWLF, the sensor can be used
with a non-synchronous trigger pulse. 12-28 V must be applied to the sync input, so that the laser will
be turned off. The following timing has to be obtained (S1 = sensor 1, S2 = sensor 2).
analog output S1
t1
0 V
12-28 V
synch. input S1
4 m
A
20 mA
0 V
12-28 V
4 mA
20 mA
t2
synch. input S2
analog output S2
Seite / Page 36
t1 is the max. time after a high signal on the synch. input of S1 until the analog value will be held.
This value will be held as long the signal on the synch. input is high.
The min. time between the high signal of S1 and the low signal of S2 is t1, also. In this case, an
optical influence between the sensors is not possible.
t2 is the time until the analog signal is ready after a low signal on the synch. input of S2. This time
depends on the reflectivity of the object and if the reflectivity changes during the hold time.
Input circuit
2t1trosneS
< 0.9 ms 0.5 ~ 2.7 ms
sm1.8
~
5.0sm7.2<
sm01~3sm01<
27kΩ
10kΩ
sync in
low: 0 .. 2V
high: 12 .. 28V
3V3
OWLF 4007+ 4013 + 4030 + 4060 FA S1 (L)
OWLF 4100 FA S1 (L)
OWLF 4100 FS S1 (L)
OWLF 4007+ 4013 + 4030 + 4060 FA S1 (L)
OWLF 4100 FA S1 (L)
OWLF 4100 FS S1 (L)

Seite / Page 37
9 Technical data
OWLF
4007 FS S1 (L)
Measuring range 200~1000 mm
Min Teach-in range ≥ 2 mm ≥ 3 mm ≥ 5 mm ≥ 10 mm ≥ 20 mm ≥ 10 mm
Resolution *1) 4~20
µm
5~60 µm0.01~0.33 mm 0.015~0.67mm 0.12~3.0 mm 0.02~0.5 mm
Linearity error *2) ±12~±60 µm±15~±200
µm
±0.03~±1.0
mm
±0.05~±2.0
mm
±0.48~±12.0
mm
±0.08~±2.0
mm
Response time *3) 300~900µs 300~900µs 300~900µs 300~900µs 300~2700µs3~10ms
Ambient light *4) < 50k Lux < 40k Lux < 8k Lux < 10k Lux < 5k Lux < 10k Lux
Typ. Temperature
coefficient *5) 0.015%v.MB/°C 0.03%v.MB/°C 0.03%v.MB/°C 0.03%v.MB/°C 0.05%v.MB/°C 0.02%v.MB/°C
deslup,deredoidresaLecruosthgiL
2ssalcresaL
mn576htgnelevaW
Laser spot *6) 1~ 0.2 mm 2 ~ 1 mm 2 mm 2 mm 2 mm 2 mm
Laser line*7) high
width
2 mm
1~0.2 mm
3~5 mm
2~1 mm
4~12 mm
2.5 mm
5.5~21 mm
2.5 mm
8.5~35 mm
2.5 mm
6~20 mm
2.5 mm
V01–0dnaAm02–4tuptuogolanA
Load resistor UOut > 100 kΩ
Load resistor IOut A20.0/)V6–sV+(<
Am001.xam/PNPtuptuomralA
Voltage supply
range 12 – 28 VDC
)Am04~V42+ieb(,Am021<tnerrucylppuS
Seite / Page 38
OWLF
Reverse polarity
protection yes (voltage supply only)
Short circuit
protection yes
munimulAcniztsac-eiDlairetamgnisuoH
mN5.1mN0.1euqrotgninethgiT
76PIssalcnoitcetorP
)gnisnednocnon(C°05+~0egnarerutarepmeT
*1) and*2) measured on white ceramic sheet
*3) the response time depends on the reflectivity of the object
*4) max. sunlight on a white measuring surface
*5) xx% of full scale measuring range / °C
*6) and*7) dimension of laser beam: OWLF 4xxx Ø
diameter OWLF 4xxx (L) size laser beam
measu
r
ing
range
height
width
measuring
range
Ø – beam
Seite / Page 39
Dimensions
OWLF 4100 FAS1 (L): OWLF 4xxx FSS1 (L):
* emitter axis 16 mm
Seite / Page 40
10 Connection diagram and pin assignment
Connection diagram Pin assignment
4013 FS S1 (L) 4030 FS S1 (L) 4060 FS S1 (L) 4100 FS S1 (L) 4100 FA S1 (L)
200~1000 mm100~600 mm50~300 mm30~130 mm30~70 mm
4007 FS S1 (L)4013 FS S1 (L) 4030 FS S1 (L) 4060 FS S1 (L)4100 FS S1 (L) 4100 FA S1 (L)