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SENS ORS OPTO SENSORS 31.4 Technical Reference Manual Chapter Issue 2 Oct 06 OPTO SENSORS Background Suppressed Opto The background suppr essed opto sensor is a dif fuse t ype sensor . The se nsor incorpor ates a backgro…
SENSORS
HALL EFFECT SENSOR
Chapter Issue 2 Oct 06 Technical Reference Manual 31.3
HALL EFFECT SENSOR
Description The board stop extended Hall effect sensor is activated by a magnet fitted to
the board stop piston. With power ON and the board stop extended, the output
transistor is switched on and the signal voltage is pulled down to 0V. When the
board stop is retracted the magnet is moved out of range and the Hall effect is
cancelled, switching off the output transistor and the signal is 12V via the digital
input circuit.
Figure 31-3 Hall Effect Schematic
Testing/
Adjustment
With Power ON and a voltmeter connected with +ve to signal (black) and -ve to
0V (blue), the following results should be obtained:
Figure 31-4 Voltage Diagram
Hall Effect Sensor
Hall Effect
Magnet
V+ (User)
Opto-isolator
1K8
0V (User)
0V
12V
12V
0V
0V
Signal
(Brown)
(Black)
(Blue)
V+
Control
Circuit
Pin 4
Pin 5
Pin 6
Locking Screw
Sensor
Board Stop Piston and Magnet
Sensor
Digital Input
Magnet
Clear
Present
12V
0V
On OnOff
Hall Effect
Signal
Present
SENSORS
OPTO SENSORS
31.4 Technical Reference Manual Chapter Issue 2 Oct 06
OPTO SENSORS
Background
Suppressed Opto
The background suppressed opto sensor is a diffuse type sensor. The sensor
incorporates a background suppression by triangulation capability, for precisely
adjusting the sensing distance.
The opto emits a pulsed red light which is reflected by a target when it enters
the sensing distance, not only sensing the reflected light but also the distance
of the object to the sensor.
When the beam of light hits the board or screen, some of the diffused light is
reflected back and the sensor NPN transistor output state is switched ON.
The pulsed beam of light, which is continuously on, is accurately focused and
is able to distinguish between the target and objects outside the scan range.
Setting Up
Procedure
The procedures for setting up the background suppressed optos are fully
detailed in the Camera System Module chapter (camera board at stop), the
Transport Rails Module chapter (board at left and board at right sensors), the
Screen Change chapter (screen position sensor) and the Rising Table Module
chapter (remote board at stop) of this manual, (Adjustments and Settings
section).
V+ (User)
NPN
Opto-isolator
1K8
0V (User)
Pin 1 12V
Pin 3 0V
Pin 2 Signal
12V
0V
Control
Circuit
View on Arrow A
Sensitivity/Focal Length
Adjustment
Red LED - Target Detected
Background Suppressed Opto
Emitter/Receiver
A
Digital Input
SENSORS
OPTO SENSORS
Chapter Issue 2 Oct 06 Technical Reference Manual 31.5
Testing Procedure If the sensor fails to operate carry out the following:
1. Disconnect the opto.
2. Short out the signal to earth on the socket.
3. Check the relevant digital input under Diagnostics - System - Display all
Digital Inputs to confirm, or otherwise, that the sensor is defective.
Figure 31-5 Voltage Diagram
Through Beam
Optos
The types of through beam opto used on this machine are:
• Fork Sensor Type
• Long Throw Type
Fork Sensor Type The through beam fork sensor transmits a beam across the gap in the opto.
When a vane enters the gap the beam is broken and the sensors output
transistor is switched on.
Long Throw Type The long throw opto works on the same principal as the through beam type but
uses two individual sensor devices (receiver and emitter) to cover a wider gap,
ie screen at centre indicator.
Figure 31-6 Through Beam Optos
Board
Absent
Present
Absent
12V
0V
Signal
Through Beam Fork Opto
Long Throw Optos
+12V
Operation Indicator
Transmitted Beam
0VSig
+12V
Signal O/P
Emitter
Receiver
0V
+12V
0V
V+ (User)
Opto-isolator
1K8
0V (User)
0V
12V
Signal
12V
0V
Vane
Control
Circuit
Pin 1
Pin 2
Pin 3
Digital Input