FMS DLS2 Digital Line and Edge Sensor User Manual

Digital Line and Edge Sensor DLS2

Document Version 1.10 03/2021 NS
Firmware Version 1.3

© by FMS Force Measuring Systems AG, CH-8154 Oberglatt – All rights reserved.

1. Safety Instructions

1.1 Description Conditions
a) Danger of health injury or loss of life

Danger: This symbol refers to high risk for persons to get health injury or loss life. It has to be followed strictly.

b) Risk of damage of machines

Caution: This symbol refers to information, that, if ignored, could cause heavy mechanical
damage. This warning has to be followed absolutely.

c) Note for proper function

Note: This symbol refers to an important information about proper use. If not followed,
malfunction can be the result.

1.2 List of Safety Instructions

• If a Digital Line Sensor DLS2 is used in combination with older web guide controllers of the types BKS110C and BKS309 V1.63 or older, a wire bridge needs to be added in the 24 V controller supply. Consult the wiring diagram and wire terminal arrangement in the operation manual of the respective controller to apply the bridge.
• With special web guide controllers e.g. of the type BKS020.xxx.480.75.D.582339 (ABG) the DLS2 sensor must be mounted on the right side of the steering frame.
• In web guiding systems all equipped with FMS components and a DLS2 sensor it may happen that the web guide controller blocks the steering frame. This protective function is activated when the line is interrupted and impossible to be detected. It avoids the steering frame from skittering away and material loses. In addition the DLS2 generates at permanent line interruption an alarm signal that can be used to shutdown the production line.

2. Functional Description DLS2

The DLS2 sensor is a digital line and edge sensor for web guiding applications. The sensor recognizes different lines and can be setup to follow either the middle of a line, the edge of a line or the edge of web. DLS2 can handle intermittent lines and also lines that are being touched or crossed by a pattern.

The sensor works with a LED CCD-array with different colours for best illumination and maximum contrast on the material. It is able to choose the best illumination by means of powerful Digital Signal Processing algorithm.

The parameters for optimal contrast, control mode, line parameters, etc. will be stored fail-safely after a calibrations process and are the reference for the following web guiding process.
A LED-Display shows the position of the line as a moving point according to its position within the detection range of the sensor. An edge is being displayed as a moving bar from either side (depending on contrast polarity).

The sensor can easily and accurately be positioned with a light spot and the focussing function. The line position can be optimised and made visible on the LED display.

Note: The DLS2 sensor cannot be combined with the web guiding controller for motorized
traverses BKS309.W.M

3. Dimensions

4. Scope of Delivery

• Sensor DLS2
• Mounting bracket (BKS.W.V.A.20×20.DLS2)
• Operation Manual

Not in the scope of delivery are:

• Connection cable (length according to customer specification).
• Sensor adjustment / mounting (BKS.W.DLS2.020.2.XXX.YYY)
  Length of guiding rod depends from the webMASTER type.

5. Installation

5.1 Mounting the Sensor
The sensor requires a square 20x20mm fixation bar that is mounted on the steering frame according to picture (Fig. 2). The sensor itself is fixed by four M4 screws on the fixation bracket which is attached to the square bar.

Fig. 2: Mounting of sensor on the square bar, view of tilting device

The distance between DLS2 and material web should be 16 mm [0.62”].
The 4 screws on the side of the sensor allow tilting the sensor around the focus point.
This can be required with reflective materials.

5.2 Right or left hand position of the sensor
Definition of Left and Right
Left and right are always seen in direction of the running web (Fig. 3).
The DLS2 line sensor can be used on both sides of the steering frame. The line sensor can replace an ultrasonic sensor US01/ 04B or an optical sensor AZS01/04A. No reconfiguration of the web guide controller is necessary after the replacement.

Note: Regardless of the mounting side, the DLS2 line sensor must always be connected to the socket for the RIGHT material sensor.

5.3 Wiring
Electrical connections:
If the sensor is used with a web guide controller built-in in a FMS steering frame of the webMASTER series, the sensor is connected with a cable 4×0.14mm2 of the respective length. We recommend using FMS original cables. The cables can be ordered at FMS.
Fig. 4 shows the sensor connector in front view with its pin assignment. The table lists the wire colour corresponding to the signal names.

5.4 Using the DLS2 with FMS Web Guide Controllers
If using the DLS2 sensor with older web guide controllers of the types BKS110C and BKS309, it may be necessary to adapt the driver strength of the 24 VDC supply of the controller to the new sensor requirements. This is achieved by adding a wire bridge in the 24V supply. The table below indicates in which cases this modification is necessary and where the bridge has to be applied.

Caution
If a Digital Line Sensor DLS2 is used in combination with older web guide controllers of the types BKS110C and BKS309 V1.63 or older, a wire bridge needs to be added in the 24 V controller supply. Consult the wiring diagram and wire terminal arrangement in the operation manual of the respective controller to apply the bridge.

6. Operation

6.1 Operational Parameters
(SW) Sensing Width: 8mm
(FD) Focal Distance: 16mm typical (14mm min., 18mm max.)
(LW) Line Width: min. 0.5mm, max. 5.0mm
(LL) Line Location: Minimum 8mm from the material edge (or from adjacent printing that may cause interference)

Line Break: DLS2 recognizes unintentionally interrupted lines. With a break in the line the sensor provides a square wave output signal. This alarm signal can be used to shutdown the production line and prevent material loses (ref. to 8.6 Normal Operation).

Line Contrast: High contrast between the line colour and the background colour (for example a black line on a white background) will provide for optimum operation of the sensor.
The DLS2 sees colours differently as the human eye. Colour combinations (red and brownish colours) are under certain circumstances not easily recognized. In particular, if there is little contrast between the background printing and the printed line, a disturbance can occur. For optimum performance where low contrast is a factor, the line location (distance between background printing and the line) can be increased e.g. from 8 to 10mm. This will benefit the operation of the sensor.

Clear Material: Tracking a line of sufficient contrast on clear material is typically straightforward provided that a background is utilized with good contrast to the line colour (e.g. black line – white background, white line – black background). A distance of approximately 3mm between clear film and background (behind the film) is recommended.

Reflective Material: It may be beneficial to adjust the sensor at an angle to the material in order to reduce reflections.

Note: FMS will evaluate your product in order to confirm suitability with the Digital Line Sensor. Please contact your local FMS Representative or FMS directly for further information.

6.2 Operation Panel
The operation panel (Fig. 6) consist of a foil type key pad and a LED-Display. The later is used to display the actual line or edge position or status information of the sensor e.g.
in form of a LED pattern. A small green LED is assigned to all keys that own an operation. These LEDs confirm the function that was activated

6.3 Operating the DLS2 via the Front Panel

7. Commissioning of the DLS2

7.1 Initialization Phase

Note: If you retrofit a DLS2 sensor to an existing controller you have to restart the controller after the installation of the sensor. This will allow the controller to detect the DLS2 sensor correctly.

When powered up the DLS2 will initialize all parameters and will load the last profile used. If no profiles or calibration data are available (e.g. when used the first time), the sensor can’t go to Detection Mode and it needs to be calibrated. In this case the LED display will indicate un-calibrated status with a light pattern with even and odd LEDs flashing in alternation.

In order to enter the Detection Mode the DLS2 needs to be calibrated. The following section 7.2 describes how to initialise and calibrate the DLS2 sensor. If an existing profile with calibration data was loaded the sensor will change to the Detection Mode.

The LED line will in this case display the position of the line or edge depending of the used mode.

7.2 Quick Installation Guide / Initialisation Procedure
The following procedure deals with commissioning the DLS2 sensor in line detection mode. The initialisation in other modes (e.g. edge detection) is carried out analogous.
Instructions and information for the other modes can be found in section 8 „Different Operation Modes“.

Initialisation Procedure:

1. Mount the sensor on the steering frame (see section 5.1 and 5.2)
2. Wiring the sensor (see section 5.3)
3. Choice of material: Choose a white paper web with a printed black line of 2 mm [0.08“]
4. Perform Horizontal Positioning of DLS2 (see section 7.3)
5. Perform Focus Adjustment Procedure (see section 7.4)
6. Do Contrast Measuring (see section 7.5)
7. Perform Calibration Procedure (see section 7.6)
8. If necessary store profile of calibration (see section 9.3)

7.3 Horizontal Positioning
In Normal Operation Mode an adjustment add can be called up by pressing three times the key. The two small green LEDs above the key will light indicating that the adjustment mode was activated. The sensor will project two small red light dots which are vertically staggered. The sensor can be positioned by moving it along the rail until the dots cover the object (line or edge) it has to recognise on the material. Once aligned, the sensor can be locked by a corrugated-head screw.

The horizontal adjustment mode can be terminated by either pressing the key once or waiting 30 sec.

7.4 Adjustment of Focus
The quality of the line or edge detection depends form several parameters. The focus is an important parameter for proper functioning of the sensor. The focus is given by the correct distance between sensor and material web. The best way of adjusting the focus distance is by using a suitable material with a printed straight line with good contrast.

There is a procedure to set the correct focus distance. The procedure is started by pressing twice the key. The small green LED on the right side of the key will light. The focus quality can be influenced by moving the sensor closer or farther away from the material. The improvement of the focus is indicated by the LED pattern as follows:

The focus adjustment procedure can be terminated by either pressing the key once or waiting 30 sec.

7.5 Contrast Measuring
The contrast describes the transition of the printed line and its background (dark – bright intersection). The higher the contrast the better will be the detection of the line. The contrast can be measured by pressing once the key. The small green LED on the
left side of the key will light. The contrast quality is visualised by the LED pattern as follows:

The Contrast Measuring can be terminated by either pressing the key once or waiting 30 sec.

7.6 Sensor Calibration
The Calibration Procedure can be considered as a learning and optimisation process of the sensor. The DLS2 gathers the characteristics of the line. Properties like line width, contrast on left line edges, contrast on the right line edge and line colour are measured and stored. The line must fulfil certain quality criteria (contrast, dimensions etc.) to be recognised as a line. If these criteria are not fulfilled the calibration will fail and an error pattern will appear on the LED-Display.

The calibration is started with the selection of the operation mode (ref. to section 8).
Press the key that complies with your application:

After the operation mode choice start the calibration by pressing the key for longer than half a second. During the calibration all LED will flash.

After a successful calibration and a test run the object data (calibration data) can be stored as a profile (ref. to section 9 „Profile Management“)

8. Different Operation Modes

The DLS2 can detect different objects on a wide range of carrier materials. Following objects can be defined:

• Straight lines
• Holographic lines
• Intermittent lines
• Holographic pattern
• Material edges
• Printed pattern

In order to optimise the detection of above objects the DLS2 sensor must be set in the right operation mode. There are 5 operation modes:

• Line Detection
• Hologram Detection
• Line Edge Detection
• Pattern Recognition
• Material Edge Detection

8.1 Line Detection
In Line Detection Mode the sensor can detect lines from 0.5 mm to maximal 5.0 mm. The characteristics of a line are gathered in the Calibration Procedure. Properties like line width and the contrast on both line edges determine and describe each particular line. A line will only be recognised as line, if following limits are adhered:

1. The line width may not differ more then ±35% from the reference line.
2. The absolute contrast may not differ more then 40% from the reference line
3. The contrast steepness may not differ more then 40% from the reference line
4. The direction of contrast change must match on both sides with the reference line.

To bring the sensor in Line Detection Mode press the key. The small green LED above the key will light to confirm that this mode is active. The sensor will always follow in this mode the centre of the line.

8.2 Line Reference Position
The line Detection mode distinguishes between three different reference positions:

• Line edge left
• Line edge right
• Line centre

The Reference Position can be chosen with the key. The small green LEDs above the key indicate which Reference Positions is active.

8.3 Material Edge or Line Detection Mode
This operation mode enables to recognise an edge of a material web or the edge of a wide line. The edge must fulfil certain parameters to be recognised as an edge:

1. The absolute contrast may not be smaller then 50% from the reference edge
2. The contrast steepness may not be smaller then 50% from the reference edge
3. The direction of contrast change must match with the reference edge

The Edge Mode can be chosen with the key. The small green LED above the key will light to confirm that this mode is active.

8.4 Hologram Detection
Materials with holograms require different illumination conditions as material with printed lines. To accommodate for this requirements there is a dedicated operation mode.

The sensor can be set to this special operation mode by pressing the key. The small green LED above the key will light to confirm that the mode was activated. The switch to Hologram Detection requires a re-calibration of the DLS2, if no profile for such a material-object combination exists. The calibration in the Hologram Detection Mode is carried out analogous to the procedure described in section 7.6 “Sensor Calibration”.

8.5 Pattern Recognition
Not operational

8.6 Normal Operation
In normal operation the display shows the position of the line or the edge as described in section 8.3. If the line or edge is missing none LED will shine. Longer unintended line interruptions are recognised by the DLS2 and it sends a special signal to the web guide controller. In such a case the controller blocks the steering frame at the actual position until the line is recognised again.

Note : In web guiding systems all equipped with FMS components and a DLS2 sensor it may
happen that the web guide controller blocks the steering frame. This protective function is activated when the line is interrupted and impossible to be detected.

The DLS2 generates at unintentional line interruption an alarm signal that can be used to shutdown the production line preventing the steering frame skittering away and creating material loses.

8.7 Reset to Default Parameter Set
Factory settings of the DLS2 can be re-established by:
Holding the two keys  while powering–up the device.
The process will be confirmed by one LED light wandering from the middle to the ends of the row and back.

9. Profile Management

Once the material/line/edge combinations have been calibrated they can be stored as a profile. The profiles contain the most important properties of the calibration (contrast, line dimension, edge quality etc.). Profiles enable a quick and flexible use of the production line since they can quickly be accessed. Machine set-up for periodically used materials is simplified (no need for recalibration) resulting in considerable time savings.

9.1 Profile Management Panel
The rose-like control panel (see Fig. 7) is used for profile management. With it profiles can be stored, deleted or implemented. After entering the operation mode „Profile Management“ (by pressing the key for longer than 0.5 sec.) the LED-Display will show the status of the profiles (see Fig. 8).

Each of the 9 elements on the LED-Display represents a profile. Hence the DLS2 can store 9 different profiles. The status of the profiles are visualised by the manner the LED-Element is shining. Following table shows the different profile states.

9.2 Call Profile and Implement
If a profile is fetched from the memory and adopted, the actual calibration data of the DLS2 is overwritten.

1. Enter operation mode „Profile Management“ by pressing the key for longer than 0.5 sec.
2. Select an existing profile with the keys. An existing profile is marked by shining LED.
3. Press the key for longer than 3 sec. to adopt the selected profile. This action
   terminates the Profile Management mode and brings the DLS2 to normal operation.

9.3 Save Profile

1. Calibrate DLS2 with material-reference-combination.
2. Check calibration with a test run.
3. Enter operation mode „Profile Management“ by pressing the key for longer than 0.5 sec.
4. Select a free profile storing place with the keys. A free profile storing place is marked by a flashing LED. It’s not possible to overwrite an existing profile without deleting the profile beforehand. .
5. Press the key for longer than 0.5 sec. to save the profile in the free storing place. The LED will change from flashing to permanent shining. If the saving process was successful, the DLS2 will go to normal operation mode.

9.4 Delete Profile

1. Enter operation mode „Profile Management“ by pressing the key for longer than 0.5 sec.
2. Select an existing profile with the keys. An existing profile is marked by shining LED.
3. Press the key for longer than 3 sec. to delete the selected profile. The LED will change from permanent shining to flashing. The sensor will then go to normal operation mode.

10. Technical Data

11. Trouble Shooting

FMS

FMS Force Measuring Systems AG
Aspstrasse 6
8154 Oberglatt (Switzerland)
Tel. 0041 1 852 80 80
Fax 0041 1 850 60 06
info@fms-technology.com
www.fms-technology.com

FMS USA, Inc.
2155 Stonington Avenue
Suite 119
Hoffman Estates,, IL 60169
(USA)
Tel. +1 847 519 4400
Fax +1 847 519 4401
fmsusa@fmstechnology.com

FMS (UK)
Aspstrasse 6
8154 Oberglatt (Switzerland)
Tel. +44 (0)1767 221 303
fmsuk@fms-technology.com

FMS (Italy)
Aspstrasse 6
8154 Oberglatt (Switzerland)
Tel. +39 02 39487035
fmsit@fms-technology.com

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