| echnical data |
| General specifications |
|
| Sensing range |
20 ... 60 mm , optimal distance: 45 mm |
| Transducer frequency |
395 kHz |
| Indicators/operating means |
|
| LED green |
indication: single sheet detected |
| LED yellow |
Indication: No sheet detected (Air) |
| LED red |
indication: double sheet detected |
| Electrical specifications |
|
| Operating voltage UB |
18 ... 30 V DC , ripple 10 %SS |
| No-load supply current I0 |
< 80 mA |
| Time delay before availability tv |
< 500 ms |
| Input |
|
| Input type |
Function input
0-level: -UB ... -UB + 1V 1-level: +UB - 1 V ... +UB |
| Pulse length |
≥100 ms |
| Impedance |
≥4 k |
| Output |
|
| Output type |
3 switch outputs NPN, NC |
| Rated operating current Ie |
3 x 100 mA , short-circuit/overload protected |
| Voltage drop Ud |
≤2 V |
| Switch-on delay ton |
approx. 15 ms (shorter response time on request) |
| Switch-off delay toff |
approx. 15 ms (shorter response time on request) |
| Pulse extension |
min. 120 ms programmable |
| Ambient conditions |
|
| Ambient temperature |
0 ... 60 °C (32 ... 140 °F) |
| Storage temperature |
-40 ... 70 °C (-40 ... 158 °F) |
| Mechanical specifications |
|
| Connection type |
cable PVC , 2 m |
| Core cross-section |
0.14 mm2 |
| Protection degree |
IP67 |
| Material |
Copper |
| Housing |
nickel plated brass; plastic components: PBT |
| Transducer |
epoxy resin/hollow glass sphere mixture; polyurethane foam |
| Mass |
150 g |
Description of sensor functions
The ultrasonic double sheet monitor is used for double sheet detection in all situations in which the automatic distinction between double and single sheets is required in order to protect machines or avoid waste production. The double-sheet monitor is based on the ultrasonic through-beam principle.
The following can be detected:
-No sheet, i.e. air, -Individual sheet -Double sheet
A microprocessor system evaluates the signals. The appropriate switch outputs are set as a result of the evaluation. Changes in ambient conditions such as temperature and humidity are compensated for automatically. The interface electronics is integrated into a compact M18 metal housing together with a sensor head.
Switching on
The sensor is equipped with 6 connections. The functionality of the connections is described in the following table. The function input (PK) is used to assign parameters to the sensor. (See Output pulse extension, Alignment aid and Program selection). During normal operation, the function input must always be securely connected with +UB or -UB, to avoid possible interference or improper functionality.
| Colour |
Switching on |
Comments |
| BN |
+UB |
|
| WH |
Switch output for single sheets |
Pulse width corresponds to the event |
| BK |
Switch output for double sheets |
Pulse width corresponds to the event |
| GY |
Switch output for air |
Pulse width corresponds to the event |
| PK |
-UB/+UB |
Function input for parameter assignment/ pulse prolongation |
| BU -UB |
-UB |
|
Normal mode
The sensor is working in normal mode if the function input (PK) is applied to -UB or +UB when the power source (Power-On) is supplied, as shown in the output pulse extension table (see below).
Displays:
Switch outputs: The switch outputs are only active in normal operation!
LED yellow: Detection of air White: WH Single sheet output
LED green: Detection of single sheets Black: BK Double sheet output
LED red: Detection of double sheets Gray: GY Air output
Output pulse extension
Switching the function input (PK) on to -UB or +UB makes it possible to select a minimum pulse width of 120 ms for all output pulses of the three switch outputs
| Switching on (PK) |
Operating behaviour (after Power-On) |
| -UB |
No output pulse extension for switch outputs |
| +UB |
Output pulse extension of all switch outputs to at least 120 ms |
Please note: This can result in a condition in which more than one switch output is switched through!
Display Mode
The selected parameter assignment of the sensor can be displayed by switching the function input (PK) to voltage-free during normal operation. The green LED displays the program number (the number of flashing pulses (1 ... 4) = the program number). The outputs are inactive during this time. If the function input (PK) is switched to voltage-free when power is supplied (Power-On), the sensor will also work in display mode. If the unit is switched to voltage-free while the function input (PK) is in operation due to an error (broken cable, coming loose because of vibration), display mode acts as a fault display.
Parameter assignment
The sensor is equipped with 4 programs for different ranges of application. This makes it possible to work with a wide range of material. The user can select the program best suited for a specific application.
The default setting, Program 1, is designed so that no change in the setting is required for most applications.
Programs
| Program number |
Notes: |
Range of materials |
| 1 |
Default setting, standard paper |
20-1200 g/m2 |
| 2 |
Thick paper, cardboard, fine corrugated
boards(DIN 55 468--1)and thin sheet metal** |
> 100 g/m2 |
| 3 |
Thin paper |
20-250 g/m2 |
| 4 |
Extremely fine paper |
< 40 g/m2 |
*) The measurements were made under the following conditions: d = 45 mm, a = 10 mm, â = 0°
*) The measurements were made under the following conditions: d = 45 mm, a = 10 mm, â = 35°
Procedure for assigning parameters
It is possible to switch to additional parameter assignment modes from the display mode:
Alignment mode--> Program selection mode --> Alignment aid mode --> (for checking)
When the function input (PK) is applied to -UB (for > 500 ms), the mode changes. When the "Program selection" mode is active, switching on function input (PK) on to +UB (for > 500 ms) selects the next program level. Disconnecting the power supply causes the system to exit the current mode with the selected program change. The switch outputs are not active while parameters are being assigned to the sensor!
Amplitude control
During installation, the amplitude control can be used to check whether the ultrasonic amplitude at the receiver is sufficient. If the transmitter is not aligned properly in relation to the receiver, maximum sound energy is not transmitted to the receiver, which may result in the incorrect detection of materials.
When the sensor detects an area of air (yellow LED lights up), the UDC begins to display the strength of the measured amplitude signal:
- if the signal is weak, the yellow LED flashes at low frequency
- the flashing frequency increases in line with the signal strength
- the yellow LED lights up continuously when the signal strength is sufficient.
The single sheet function (green LED) and double sheet function (red LED) are now active. This can be used to check the correctfunction of the sensor.
Program selection
In the program selection mode, the current program is displayed by the green LED (number of flashing pulses = program number).
Applying the adjustment input (PK) to +UB (for > 500 ms) causes the next program to be selected in cyclic sequence (program 1 follows through to program 4).
Notes:
A complete device consists of an ultrasonic emitter and an evaluation unit with an ultrasonic emitter. The sensor heads are optimally adjusted to each other when they leave the factory. Therefore, they must not be used separately or exchanged with other devices of the same type. The plug connector on the emitter/receiver connection cable is only intended to be used for easier mounting, not to replace units.
Very light papers (for example handkerchiefs) or perforated papers are not always suitable for double sheet detection because of their physical characteristics.
If two or more double sheet controls are used in the immediate vicinity of each other, there may be mutual interference between them, which can result in improper functionality of the devices.
Mutual interference can be prevented by introducing suitable countermeasures when planning systems.
When installing, care has to be taken that the ultrasonic signal cannot pass around the material that is to be detected, due to multiple reflections. This can happen if large surfaces are present at right angles to the direction of sound propagation. This can be the case if unsuitable mounting brackets are used, or if assemblies with large surface are part of the machine. In the latter case such machine parts should be covered by sound absorbing material or a different location for the installation should be chosen.
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