Pepperl+Fuchs VDM18-100/20/122/151 User manual

HANDBUCH / MANUAL / MANUEL
FACTORY AUTOMATION
VDM18-100/20/122/151
VDM18-100/20/88/122/151
VDM18-300/20/122/151
VDM18-300/20/88/122/151
VDM18-300/21/122/151

Copyright (Deutsch)
Die Wiedergabe bzw. der Nachdruck dieses Dokuments, sowie die entsprechende Speicherung in Datenbanken
und Abrufsystemen bzw. die Veröffentlichung, in jeglicher Form, auch auszugsweise, oder die Nachahmung
der Abbildungen, Zeichnungen und Gestaltung ist nur auf Grundlage einer vorherigen, in schriftlicher Form vor-
liegenden Genehmigung seitens Pepperl+Fuchs GmbH, zulässig.
Für Druckfehler und Irrtümer, die bei der Erstellung der Betriebsanleitung unterlaufen sind, ist jede Haftung
ausgeschlossen. Liefermöglichkeiten und technische Änderungen vorbehalten.
Erstveröffentlichung August 2004.
Copyright (Englisch)
No part of this document may be reproduced, published or stored in information retrieval systems or data bases
in any manner whatsoever, nor may illustrations, drawings and the layout be copied without prior written permis-
sion from Pepperl+Fuchs GmbH.
We accept no responsibility for printing errors and mistakes which occurred in drafting this manual. Subject to
delivery and technical alterations.
First publication August 2004
Copyright (Français)
Toute reproduction de ce document, ainsi que son enregistrement dans une base ou système de données ou
sa publication, sous quelque forme que ce soit, même par extraits, ainsi que la contrefaçon des dessins et de la
mise en page ne sont pas permises sans l’autorisation explicite et écrite de Pepperl+Fuchs GmbH.
Nous déclinons toute responsabilité concernent les fautes éventuelles d’impression et autres erreurs qui
auraient pu intervenir lors du montage de cette brochure. Sous réserve de modifications techniques et de
disponibilité pour livraison.
Première publication Août 2004

3
Maßzeichnung / Dimensional drawing / Plan coté
Abb. 1 / Illustr. 1 / Fig. 1
Anschluss / Wiring / Raccordement
Typ / Type / Ref. Pin 1 Pin 5
VDM18 .../88 RS485 Y/A RS485 Z/B
Abb. 2 / Illustr. 2 / Fig. 2
Emitter
Receiver
Version X (mm)
VDM18-100 18.4
VDM18-300 21.5
4.3
4.3
13.5
17
4
50
X11
4
50
4
M12 x 1
40
44
18
44
46
Analog +
Analog -
1
2
3
4
5
6
7
8
n.c.
n.c.
+UB
0 V
Q1
Q2
Option /20 - 2 x PNP Option /21 - 2 x NPN
Analog +
Analog -
1
2
3
4
5
6
7
8
n.c.
n.c.
+UB
0 V
Q1
Q2

4
Inhalt / Content / Contenu
Deutsch ................................................................................................................... 5
English................................................................................................................... 26
Français................................................................................................................. 47

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Content
Signs and Symbols......................................................................................................................................26
Safety information .......................................................................................................................................26
Appropriate use ...........................................................................................................................................27
Performance characteristics........................................................................................................................27
Mode of function..........................................................................................................................................27
Mounting......................................................................................................................................................28
Electrical installation ...................................................................................................................................29
Instructions of use .......................................................................................................................................30
General use.................................................................................................................................................30
Settings........................................................................................................................................................32
Functions.....................................................................................................................................................32
Reset ...........................................................................................................................................................34
Unlocking keys ............................................................................................................................................34
Averaging ....................................................................................................................................................35
Automatic zero mode...................................................................................................................................35
Automatic centre mode................................................................................................................................36
Maximum hold mode ...................................................................................................................................36
Difference hold mode ..................................................................................................................................37
Measured value hold mode .........................................................................................................................37
Differential measurement mode ..................................................................................................................38
Transmission protocol .................................................................................................................................40
Bus commands............................................................................................................................................41
Explanations on bus commands..................................................................................................................42
Optical data (typ.) ........................................................................................................................................43
Electrical data (typ.),....................................................................................................................................43
Mechanical data ..........................................................................................................................................43
Order information.........................................................................................................................................44

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Signs and Symbols
Safety information
Warning
This symbol signals passages in the manual which must be observed at all times. Non-compliance can
cause injuries or material damage.
Warning Laser
This symbol appears in front of warning passages concerning the danger of laser beams.
Information
This symbol signals passages with useful information.
It is essential that this manual, and the safety information in particular, is read, thoroughly un-
derstood and observed before setting the VDM18 sensor into operation.
The VDM18 sensor may only be connected, mounted and adjusted by qualified personnel.
Interventions and alterations to the device are not permissible!
The VDM18 sensor is not a safety component as described by EU machine directives and must
never be used in applications where human safety is at risk.
The VDM18 sensor complies with laser protection class 2 according to DIN EN 60825-1, status
2008-05. The technical requirements comply with EN 60947-5-2, 2000 edition.
Never look into the path of the laser. Do not suppress the reflex to close the eyelids.
Gazing into the beam path for longer periods can damage the retina of the eye.
When mounting the sensor, ensure if possible that the beam path is sealed off at the end. The
laser must not be directed at people (head height). When aligning VDM18, ensure that there are
no reflections on reflective surfaces.
Should the safety label on the VDM18 sensor be partly covered due to its installation position,
other safety labels are to be positioned on visible parts of the sensor. When applying the new
safety label, make sure that you cannot look into the laser beam whilst reading it.

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Appropriate use
The VDM18 sensor is not authorised for use in protecting human safety on machines and during
technical applications.
The VDM18 is an optical sensor and measures distances without contact. When combined with another VDM18
sensor, the thickness of objects can also be measured.
Performance characteristics
• Operating range VDM18-100: 30 – 100 mm
• Operating range VDM18-300: 80 – 300 mm
• 2 digital outputs
• Analogue output 4-20 mA
• Compact design 50 x 50 x 17 mm
• High resolution (0.1 % of measuring range)
• Option /88 with serial bus interface (RS 485 half-duplex)
• “Teach-in” settings also possible per software
• Wide functional range
Mode of function
The VDM18 sensor measures according to the principle of triangulation. The distance between the object and sensor
is determined on the basis of the position of the light spot on the detector.
Operating range (Factory setting)
30 mm
80 mm
100 mm
300 mm
Illustr. 3
On
Off
20 mA
OK LED (green)
(Good Target)
Analogue
output
(invertible) 4 mA
VDM18-100 ...
VDM18-300 ...

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Mounting
Sensor alignment
Position VDM18 in a way that the distance to the object is within the working range of the sensor.
Screw the VDM18 sensor to the mounting bracket, e.g. type OMH-VDM18 (not included in delivery) or a suitable
device. Only use the holes provided in the housing (see dimensioned drawing) for this purpose.
If steps, moving or striped objects are to be detected, the front panel of the sensor should be mounted at a right
angle to the direction of movement or stripes (Illustr. 5 + 6).
With very reflective objects, the sensor must be mounted at an angle of approx. 5° (Illustr. 7).
To optimise measurements, the VDM18 sensor is to be given constructive protection from vibra-
tions.
The VDM18 sensor is now mounted.

Z Z
 
Illustr. 5 Linear movement Illustr. 6 Rotating movement Illustr. 7 Reflective object
Illustr. 4
Light spot representation
Emitter
Receiver
C
E11
A
B
D
VDM18-100 VDM18-300
30A (mm) 80
100B (mm) 300
C (mm)
D (mm)
E (mm)
8.5
1.5 x 3 1.5 x 3.5
1.5 x 3.25 2 x 4.5
29.4 32.5

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Electrical installation
Warning: Pin 1 and pin 5 must not be connected to operational voltage as this will destroy the
VDM18 sensor.
Turn the sensor connector plug according to the installation position (Illustr. 1) so that the connection cable can be
freely connected without being bent.
Insert the socket of the connection cable into the VDM18 connector and screw tight
For example, secure the connection cable from sliding with a cable tie .
Connect VDM18 as shown in Illustr. 8
Connection Colour Use Comments
1 (WH) White RS485 Y/A /88 option only
2 (BN) Brown + UB
3 (GN) Green As signal output Q1or input with optional input functions (see
“Settings” page 32)
Q1
4 (YE) Yellow As signal output Q2or switching function “good target” (detec-
table object in measuring range)
Q2or good target
5 (GY) Grey RS 485 Z/B /88 option only
6 (PK) Pink QA + analogue measurement
7 (BU) Blue - UB
8 (RD) Red QA - analogue mass
Once power supply has been connected, the VDM18 is ready for operation after a short stand-by delay
(< 300 ms).
For maximum precision, please allow for a heating period (approx. 5 minutes).
Illustr. 8 Connection diagram
Type Pin 1 Pin 5
VDM18 .../88 RS485 Y/A RS485 Z/B
Analog +
Analog -
1
2
3
4
5
6
7
8
n.c.
n.c.
+UB
0 V
Q1
Q2
Option /20 - 2 x PNP Option /21 - 2 x NPN
Analog +
Analog -
1
2
3
4
5
6
7
8
n.c.
n.c.
+UB
0 V
Q1
Q2

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Instructions of use
Control panel
The VDM18 has various modes and is configured using the S and T buttons.
Button
S
Set button: Change / confirm a setting or set a switching point
T
Toggle button: Select a function (proceed to the next function)
The selected settings and signal condition are indicated by LEDs.
LED Colour Use/Description
BA Green Power supply indicator
On: ready (run mode)
Flashing: setting mode is active
ZA Red Status indicator
Function activated/not activated, or confirmation signal
Q1Yellow Q1 input/output
Q2Yellow Q2 input/output
H Green Q1trigger input or Q1enable input function active
OK Green Good target (object detected and in measuring range)
T Green Pulse stretching function is active
Z Green Q1automatic centre or Q1automatic zero function is active
The table of functions on page 32 explains the further significance of the LEDs: Q1, Q2, H, OK, T and Z
General use
The following four steps are used to configure the VDM18 sensor:
1. Activate setting mode
Press the S and T buttons simultaneously for 3 seconds
After this period, the power supply indicator BA flashes
set VDM18, see Illustr. 9. The LEDs show the status of function no. 1 (page 32)
When all the LEDs start immediately flashing
 Unlock VDM18, see paragraph “Unlocking keys” on page 34
2. Select functions (see page 32)
Press the T button to select the next function in the function table.
The function number is indicated by a clear LED pattern and the function status is indicated by the status indicator ZA
(LED on = active, LED off = not active).
The sensor only switches to the next function when the T button is released.
Illustr. 9
BA ZA
Q1Q2
H OK
T Z
S
T

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If no change occurs:
 Press T button for longer
The first function follows the last available function.
If the wrong function is selected by mistake, it is not possible to jump directly back to the pre-
vious function number.
 Press the T button several times until the required function reappears.
 Or deactivate setting mode (see point 4) and repeat procedure from step 1.
3. Setting the function status
Press the S button to alter the status of a particular function. The status indicator alters according to the table of
functions. Settings are immediately effective but must still be saved as described in point 4.
Should the status indicator not alter or not light up whilst S is pressed
 Check the position of the VDM18 sensor in relation to the measuring range and adapt if necessary
To reset the setting, press the S button once again (is not valid when transferring measured value as switching point!)
4. Deactivate setting mode
First press the T button and then simultaneously press the S button. All settings are then saved. Once the S button is
released, the sensor is in run mode. The BA power supply indicator is permanently alight.
Should the power supply fail during the setting procedure, all settings are lost.

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No. LED Muster Description “ZA” status indicator Factory setting
1Select Q1 output mode. On = Q1is a signal output
Off = Q1is not a signal output
On
2Transfer of current meas. value as 1st
switching point of Q1. signal output.
On* = Measured value valid
Off* = Measured value invalid
Half measuring
range
3 Scanning zone: Transfer of current meas.
value as 2nd switching point of Q1signal
output. Q1must be signal output (see
function no 1).
On = Measured value valid
Off = Measured value invalid
Off
4N.C./N.O. change-over of switching
functions for Q1.
On = N.C.
Off = N.O.
N.O.
5Q2output mode. On = Q2is a signal output
Off = Q2displays good target
Off
6Transfer of current meas. value as 1st
switching point of Q2signal output.
Q2 must be signal output (see function
no 5)
On* = Measured value valid
Off *= Measured value invalid
Good Target
7Scanning zone: Transfer of current meas.
value as 2nd switching point of Q2signal
output. Q2must be signal output (see
function no 5).
On = Measured value valid
Off = Measured value invalid
Off
8N.C./N.O. change-over of switching
functions for Q2.
On = N.C.
Off = N.O.
N.O.
9Pulse stretching of Q1and Q2by 50 ms. On = Pulse stretching on
Off = Pulse stretching off
Off
10 Q2signal output shows status “good
target”. Switching signal can be inverted
with function no 8.
On = Object within...
Off = Object outside...
...measuring range
On
Settings
The VDM18 sensor can be configured as follows with functions 1 to 26 in setting mode (teach-in).
Button
S
Set button: Change / confirm a setting or set a switching point
T
Toggle button: Select a function (proceed to the next function)
Functions
* as long as the S button is pressed

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No. LED Muster Description “ZA” status indicator Factory setting
11 Q1trigger input mode:
With rising edge on Q1, measured value is
held until the next trigger occurs.
On = Q1is a trigger input
Off = Q1is not a trigger input
Off
12 Q1enable input mode:
Used to switch laser beam on and off.
Laser beam is on when Q1= +UB. If Q1
= - UB, the laser beam is switched off.
Last measured value remains. When re-
activated, the response time is prolonged
according to the set mean value.
On = active
Off = not active
Off
13 Switches off averaging:
The first measured value is taken into
account (page 35).
On = Averaging off On
14 Switches on 4 ms averaging:
the first 10 meas. values are taken into
account (page 35).
On = active
Off = not active
Off
15 Switches on 40 ms averaging:
all (max. 100) meas. values are taken into
account (page 35).
On = active
Off = not active
Off
16 Set analogue output 0% (4 mA):
When S button is activated, the current
meas. value corresponds with 0% value of
the analogue output.
On* = Object within…
Off* = Object outside...
...measuring range
0% = 4 mA = end
of meas. range
17 Set analogue output 100% (20 mA): When
S button is activated, the current meas.
value corresponds with 100% value of the
analogue output.
On* = Object within…
Off* = Object outside...
...measuring range
100% = 20 mA
= start of meas.
range
18 Q1automatic zero mode:
For characteristic curve displacement. If
Q1= +UB, the current measuring signal
is set to the analogue value 0 % = 4 mA.
The incline of the characteristic curve is
maintained. If exceeded, the characteri-
stic curve ends at the start or end of the
measuring range.
On = Automatic zero active
Off = Autommatic zero not active
Not active
19 Q1automatic centre mode: displacement
of centre of characteristic curve. If Q1=
+UB, the current measuring signal is set to
the analogue value
50 % = 12 mA. The incline of the charac-
teristic curve is maintained. If exceeded,
the characteristic curve ends at the start
or end of the measuring range.
On = Automatic centre active
Off = Automatic centre not
active
Not active
* as long as the S button is pressed

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No. LED Muster Description “ZA” status indicator Factory setting
20 Q1maximum hold mode:
Provided
Q1 = +UB, the max. recorded measured
value is stored.
If Q1= -UB, the determined value is trans-
mitted at the analogue output. A minimum
hold can be set by inverting the analogue
characteristic curve (analogue 100% point
< analogue
0 % point).
On = Maximum hold active
Off = Maximum hold not active
Not active
21 Q1difference hold mode:
Provided Q1 = +UB, the difference
between the measured values is saved.
When Q1= -UB, the determined value is
transmitted at the analogue output.
On = Difference hold active
Off = Difference hold not active
Not active
22 Activate factory settings:
When the S button is pressed, the factory
setting is activated.
ZA lights up as long as the S button
is pressed
Not active
23 Locking keys:
If function is activated locking becomes
active once the setting mode has been
quit. Cancel locking with RESET or the
unlocking function (see “Unlocking keys”)
On = Locking is active
Off = Locking is not active
Not active
24 Meas. value hold mode:
If no object is in the measuring range
(good target = off), the last meas. value is
held at the analogue output.
On = Meas. value hold is active
Off = Meas. value hold is
not active
Not active
25 Differential measurement mode master:
Activate/deactivate (option /88 only)
Description see differential measurement
mode (page 38).
On = Differential measurement
mode - master is active
Off = Differential measurement
mode - master is not active
Not active
26 Differential measurement mode slave:
Activate/deactivate (option /88 only)
Description see differential measurement
mode (page 38).
On = Differential measurement
mode - slave is active
Off = Differential measurement
mode - slave is not active
Not active
Reset
When switching on the sensor (power on), keep the S button pressed (approx. 10 seconds) until the
LED lights stop flashing and are permanently on. The BA power supply indicator is green. When the
S button is released, a Reset is carried out which returns the VDM18 to delivery status where factory
settings are active.
(See table of functions page 32-34).
Unlocking keys
When switching on the sensor (power on), keep the T button pressed (approx. 10 seconds) until the
LED lights stop flashing and are permanently on. The ZA status indicator is red. When the T button is
released, the setting mode is unlocked.

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Automatic zero mode
The output characteristic curve 4 – 20 mA is displaced with this function. When the automatic zero mode is activated
and Q1= +UB, the current measured value is equated with the output value of 0% = 4 mA. The incline of the cha-
racteristic curve is maintained and the minimum and maximum values of the characteristic curve are limited by the
measuring range.
The distance to the object must be within the measuring range.
Averaging
The measuring result (output signal) is smoothed by averaging. The measured values are read continuously into a
memory and the arithmetical mean is formed. Functions 14 and 15 (page 33) determine the number of measure-
ments (10 or 100) to be used for averaging.
With a scanning rate of 0.4 ms per measurement, the response time lies between 0.4 ms (without averaging) and 40
ms.
Example of use: When measuring rough surfaces, it is possible to counter-balance fluctuations in measured values.
Illustr. 10 Output characteristics in relation to arithmetical mean
Response time t(s)
0.4 ms = measured value (no average)
4 ms = averaging with 10 measured values
40 ms = averaging with 100 measured values
Response time
Analogue signal Factory setting
Autom. zero at 150 mm
Measuring object
I(mA)
100% (20 mA)
50% (12 mA)
0% (4 mA)
+UB
-UB
Q1
100% (20 mA)
0% (4 mA)
80 150 300 mm
t(s)
Illustr. 11 Illustr. 12
Direction of movement

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Automatic centre mode
The output characteristic curve 4 – 20 mA is displaced with this function. When the automatic centre function is
activated and Q1= +UB, the current measured value is equated with the output value of 50% = 12 mA. The incline of
the characteristic curve is maintained and the minimum and maximum values of the characteristic curve are limited
by the measuring range.
The distance to the object must be within the measuring range.
Maximum hold mode
When maximum hold mode is activated and Q1= +UB, this function detects the maximum value of the measuring
signal and stores it.
If Q1= -UB, the last maximum value is transmitted at the analogue output.
Example of use: determining the maximum value of a shaft
The minimum value can be determined by inverting the analogue output characteristic (see function no. 16 and 17).
Analogue signal
100% (20 mA)
50% (12 mA)
+UB
-UB
Q1
t(s)
0% (4 mA)
Autom. centre at 120 mm
100% (20 mA)
50% (12 mA)
0% (4 mA)
80 120 300 mm
190
Analogue value
Analogue output
Q1= +UB= Sample. Collect measured values
Q1= -UB= Display. Last maximum of analogue signal at
analogue output
AABB
A
B
100% (20 mA)
+UB
-UB
Q1
0% (4 mA)
100% (20 mA)
0% (4 mA)
14 mA
8 mA
1
1
2
2
1
2
Illustr. 13 Illustr. 14
Illustr. 15

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Difference hold mode
When the difference hold function is activated and Q1= +UB, this function detects the difference between the mini-
mum and maximum value of the measuring signal and stores it.
If Q1= -UB, the last differential value is transmitted at the analogue output.
Example of use: Checking the contents of open containers or packages.
Measured value hold mode
When this function is activated, the last valid measured value is saved.
When no object is in the measuring range, the last valid measured value is transmitted at the analogue output. The
current value is only displayed again when an object is within the measuring range (OK LED = on).
Example of use: Maintain position of tool during change-over of work piece when machining.
Behaviour of analogue output with and without measured value hold.
Start of measuring range
End of measuring range
With measured value hold
Without measured value hold
Analogue valueAnalogue output
Q1= +UB= Sample. Collect measured values
Q1= -UB= Display. Last maximum of analogue signal at
analogue output
AB BB
B
A
A
100% (20 mA)
0% (4 mA)
0% (4 mA)
12 mA
2 mA
1
1
2
2
1
2
100% (20 mA)
+UB
-UB
Q1
100% (20 mA)
0% (4 mA)
0% (4 mA)
100% (20 mA)
Good Target Q2
Illustr. 16
15500149
Illustr. 17
ON
OFF

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3. One of the sensors must be configured as a slave. Activate function 26 (see “Settings”, page 32)
Illustr. 19
The following steps must be carried out for differential measurement:
1. Mount both VDM18.../88 sensors.
2. Connect sensors according to the electrical connection diagram
Illustr. 18
Measuring range
1
2
3
Differential measurement mode
Differential measurement can only be used with /88 option of VDM18.
Simultaneous connection to SPC control or a PC via the RS 485 interface is not possible with
differential measurement.
With this measuring procedure, two VDM18.../88 sensors are connected to one another. The measuring ranges can
overlap (1), be directly adjacent (2) or apart (3) (Illustr. 18).
To achieve optimum use of the measuring range, the measuring object should if possible be aligned in the centre of
the measuring range.
Analog +
Analog -
1
2
3
4
5
6
7
8
RS485Z/B
RS485Y/A
+UB
0 V
Q1
Q2
Analog +
Analog -
1
2
3
4
5
6
7
8
RS485Z/B
RS485Y/A
+UB
0 V
Q1
Q2
Master Slave

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4. Insert reference object of known width in measuring range.
Warning: LED “OK” (Good target) must light up on both sensors.
5. Configure the second VDM18.../88 sensor as the master. Activate function no. 25 (page 34).
Warning: The sensor can only be configured as a master when the object is inside the measuring range of both
sensors (see point 4).
6. The analogue value on the master corresponds with the measured reference width and the 50% value (autom.
centre function) of 12 mA. All function settings on the master are based on the difference in thickness.
7. Feed objects into the measuring range to start measurement.
8. The measured value provides the difference to the reference width and is at the analogue output of the master.
The analogue output of the slave supplies the distance to the object.
We recommend resetting sensors to factory setting (function 22, page 34) before configuration of
sensors as master or slave.
In differential measurement mode, resolution and linearity must be multiplied by 2, because 2
sensors are used.

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Sensor configuration with the VDMConfig software
The operating software “VDMConfig” is available to facilitate programming of versions /88 Its simulation mode
indicates the correct bus commands for the respective case.
For more information see our homepage: www.pepperl-fuchs.com and the order information on page 44.
Transmission protocol
Transmission frame
The bus-compatible RS 485 interface of VDM18.../88 operates in half-duplex mode (1 Stopbit, no parity).
As a rule, the VDM18.../88 sensor is a slave and only sends data when addressed by a higher ranking control system
(master) except difference measuring.
A baudrate of 38,4 KBaud and the following protocol must be observed for data transmission:
• 7 data bits + 1 address bit (MSB) MSB 6.....1 LSB
address bit 7 data / address bits
Procedure:
When the address bit has been set, the VDM18.../88 sensor compares the bus address with its own. If they match,
the VDM18.../88 sensor interprets all further data and sends an appropriate feedback signal.
The structure of the transmission frame is as follows:
1st byte 2nd byte 3rd byte ... Last byte
Request from master:
Address of slave Length Command Parameter(s) Checksum
Answer from slave:
Address of slave Length Command Parameter(s) Checksum
Length = Number of characters incl. checksum and address byte
Command = See table of bus commands on page 41
Parameters = Parameter byte 0 to n, depending on command. The slave sends the requested data
in this range.
Checksum = Exclusive OR of all characters sent incl. address byte
Slave answers:
Address of slave 4 N*1Checksum
Address of slave 4 Y*2Checksum
Address of slave 4 + n Y 1st parameter, 2nd parameter,
3rd parameter, …, n parameter
Checksum
*1 is sent when an error regarding checksum, frame length or parameter / command occurs.
*2is sent when the command has been carried out.