Công nghệ SMT máy DEK cảm biến sensors INTRODUCTION HALL EFFECT SENSOR OPTO SENSORS Ultrasonic Sensor CAPACITIVE PROXIMITY SENSOR REED SWITCH SENSOR SAFETY SWITCH MICROSWITCH SENSOR PRESSURE SENSOR GIANT MAGNETO RESISTIVE SENSOR (GMR) STRAIN GAUGE SENSOR TEMPERATURE AND HUMIDITY SENSOR
SENSORS INTRODUCTION CHAPTER 36 SENSORS INTRODUCTION This chapter gives details of the various sensors used in the machine All sensors used on the machine fall within three categories, these are: Solid State Switches • Solid State Switch Sensors • Conventional Switch Sensors • Analogue Sensors The machine uses the following types of solid state sensor switches: • Hall Effect Sensors • Opto Sensors • Ultrasonic Sensor • Capacitive Proximity Sensor In all cases to initiate a logic (on state) at the input, the sensor must connect the signal input to 0V This may not, however, translate to a positive condition after software processing Digital Input 12V V+ (User) 1K8 Control Circuit Signal I/P Opto-isolator Solid State Sensor 0V (User) Figure 36-1 Typical Solid State Schematic Testing Solid state sensors can only be tested in circuit as they require a logic supply voltage and a pull up resistor on the sensor output Check for the 12V logic supply to the sensor Activate the sensor according to type and measure the voltage at the output terminal with respect to 0V The sensor output signal should change between approximately 0V and 12V (see individual sensor descriptions for more details) Chapter Issue Jan 08 Technical Reference Manual 36.1 SENSORS INTRODUCTION Conventional Switches The machine uses the following types of conventional switch sensors: • Reed Switch • Safety Switch • Microswitch • Pressure Switch In all cases to initiate a logic (on state) at the input, the sensor must connect the signal input to 0V 12V Digital Input V+ (User) 1K8 Signal I/P Opto-isolator Conventional Switch 0V (User) Figure 36-2 Typical Conventional Switch Schematic Testing Activate the sensor according to type and measure the voltage at the output terminal with respect to 0V The sensor signal output should change between approximately 0V and 12V Remove switch from the circuit and measure continuity, when activated In all cases check digital inputs under diagnostics at the MMI Analogue Sensors Sensor Location 36.2 The machine uses the following types of analogue sensor: • Giant Magneto Resistive Sensor • Strain Gauge Sensors • Temperature and Humidity Sensor Machine location for individual sensors are detailed in the respective module chapter overview sections, ie Camera Y Home Sensor - can be found in the Camera System Module chapter Technical Reference Manual Chapter Issue Jan 08 SENSORS HALL EFFECT SENSOR 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 Board Stop Piston and Magnet Sensor Sensor Locking Screw Hall Effect Sensor Hall Effect Magnet Control Circuit Digital Input Pin V+ (Brown) Pin Signal (Black) Pin 0V (Blue) V+ (User) 12V 12V 0V 1K8 0V Opto-isolator 0V (User) Figure 36-3 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: Magnet Present Hall Effect On Clear Off Present On 12V Signal 0V Figure 36-4 Voltage Diagram Chapter Issue Jan 08 Technical Reference Manual 36.3 SENSORS OPTO SENSORS 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 Emitter/Receiver A Background Suppressed Opto Sensitivity/Focal Length Adjustment Red LED - Target Detected View on Arrow A Digital Input NPN Control Circuit Pin 12V 12V Pin Signal 0V V+ (User) 1K8 Pin 0V Opto-isolator 0V (User) Setting Up Procedure 36.4 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) Technical Reference Manual Chapter Issue Jan 08 SENSORS OPTO SENSORS Testing Procedure If the sensor fails to operate carry out the following: Disconnect the opto Short out the signal to earth on the socket Check the relevant digital input under Diagnostics - System - Display all Digital Inputs to confirm, or otherwise, that the sensor is defective Absent Board Absent Present 12V Signal 0V Figure 36-5 Voltage Diagram Through Beam Optos Fork Sensor Type The types of through beam opto used on this machine are: • Fork Sensor Type • Long Throw 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 high or low depending on connection (L) Transmitted Beam Pin - +V Pin - (L) Pin - Signal O/P Pin - 0V Operation Indicator Through Beam Fork Opto Digital Input (L) Vane +V (User) +V Control Circuit Signal O/P 12V 0V 1K8 0V Opto-isolator 0V (User) Figure 36-6 Through Beam Optos Testing Procedure If the sensor fails to operate carry out the following: Disconnect the opto Chapter Issue Jan 08 Technical Reference Manual 36.5 SENSORS OPTO SENSORS Short out the signal to earth on the socket Check the relevant digital input under Diagnostics - System - Display all Digital Inputs to confirm, or otherwise, that the sensor is defective 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 Receiver Emitter 0V 12V 12V 0V Signal O/P Long Throw Optos Digital Input Receiver Emitter Control Circuit 12V Signal O/P 12V V+ (User) 12V 0V 1K8 0V 0V Opto-isolator 0V (User) Figure 36-7 Long Throw Opto Testing/Adjustment If the sensor fails to operate, confirm the sensor is faulty as follows: Disconnect the long throw opto receiver Short out the signal to earth on the socket Check the relevant digital input under Diagnostics - System - Display all Digital Inputs to confirm, or otherwise, that the sensor is defective Out Vane Off Indication Light In On Out Off 12V Signal 0V Figure 36-8 Voltage Diagram 36.6 Technical Reference Manual Chapter Issue Jan 08 SENSORS ULTRASONIC SENSOR ULTRASONIC SENSOR Description The ultrasonic sensor transmits a conical shaped area of ultrasonic sound waves, some of the waves are rebounded back to the receiver in the sensor When a board passes over the sensor the amount of rebounded sound changes, switching the output of the sensor Operation Indicator Set/Teach Button SET A View on Arrow A Ultrasonic Sensor Pin Control/Teach Digital Input Pin V+ (User) 12V Control Circuit 1K8 Pin Signal +V 0V Opto-isolator Pin 0V 0V (User) Figure 36-9 Ultrasonic Sensor Testing Procedure If the sensor fails to operate carry out the following: Disconnect the opto Short out the signal to earth on the socket Check the relevant digital input under Diagnostics - System - Display all Digital Inputs to confirm, or otherwise, that the sensor is defective Absent Board Present Absent 12V Signal 0V Figure 36-10 Voltage Diagram Chapter Issue Jan 08 Technical Reference Manual 36.7 SENSORS CAPACITIVE PROXIMITY SENSOR CAPACITIVE PROXIMITY SENSOR Description A capacitive proximity sensor consists of an RC oscillator which emits a frequency field When the target, in this case the solder paste, moves away from the sensing range (ie paste low), the capacitance increase effectively changes the internal current which is detected by an adjustable trigger The control circuit switches the output transistor on Sensor Bracket Sensor Sensor Bracket LED Paste Level Sensor LED Adjuster and Indicator Capacitive Proximity Switch Paste Cartridge Paste Level Sensor Paste RC Frequency Field Control Circuit Digital Input Pin 12V Pin 12V 0V Pin 0V V+ (User) 1K8 Opto-isolator Solder Paste 0V (User) Figure 36-11 Capacitive Proximity Sensor 36.8 Technical Reference Manual Chapter Issue Jan 08 SENSORS CAPACITIVE PROXIMITY SENSOR Testing/ Adjustment Node Absent Off Operation Indicator Present On Absent Off 12V Signal 0V Figure 36-12 Voltage Diagram Setting Up Procedure Chapter Issue Jan 08 The procedure for setting up the capacitive proximity sensor is fully detailed in the Paste Dispenser System chapter of this manual, (Adjustments and Settings section) Technical Reference Manual 36.9 SENSORS REED SWITCH SENSOR REED SWITCH SENSOR Description A reed switch is activated by a magnet fitted to either the piston or drive shaft of the actuator One side of the switch is connected to the input, the other side of the reed switch is connected to 0V The input is connected to +12V via a pull up resistor, so under normal conditions the input is pulled high When the reed switch is activated by a magnet, the reed switch closes and pulls the input down to 0V (low) Pneumatic Cylinder Reed Switch Sensor Locking Screw Pneumatic Cylinder with Reed Switch Rotary Actuator Board Stop In Reed Switch Rotary Actuator with Reed Switch Digital Input V+ (User) N0 (normally open) (Red) 12V 0V (Black) 1K8 Opto-isolator 0V (User) Figure 36-13 Reed Switch Schematic 36.10 Technical Reference Manual Chapter Issue Jan 08 SENSORS REED SWITCH SENSOR Testing/ Adjustment Setting of the sensor is necessary in order to: • Ensure that switching takes place in the correct position • Ensure correct sensing, ie closing when piston extended/retracted NOTE For adjustment of ProFlow cassette low sensor refer to ProFlow chapter of this manual Magnetic Piston Reed Switch Retracted Extended Retracted Closed Open Closed 12V Signal 0V Figure 36-14 Voltage Diagram Chapter Issue Jan 08 Technical Reference Manual 36.11 SENSORS SAFETY SWITCH SAFETY SWITCH Description The safety switch is a device fitted to the printhead cover designed to provide operator safety The design of the internal anti-tamper cams also act as a latch A 6mm movement of the switch activator 'open circuits' the safety contacts There are sets of contacts in the switch but only of the sets, both normally open (NO), are used by the machine One set of contacts is used as a digital input to inform the PC that a cover has been opened, the other set is used as part of the system safety loop to cut the system power The cover interlock signal is pulled low when the front cover is opened 14 13 22 21 34 33 Safety Switch Digital Input V+ (User) 12V 0V Part of System Safety Loop 21 13 22 14 1K8 Opto-isolator 0V (User) Figure 36-15 Safety Switch Schematic 36.12 Technical Reference Manual Chapter Issue Jan 08 SENSORS SAFETY SWITCH Testing/ Adjustment To adjust the safety switch, physically move the body of the switch to ensure that 6mm of cover movement activates the switch Cover Closed Closed Circuit Continuity Open Open Circuit Closed Closed Circuit 12V Signal 0V Figure 36-16 Voltage Diagram Chapter Issue Jan 08 Technical Reference Manual 36.13 SENSORS MICROSWITCH SENSOR MICROSWITCH SENSOR Description The microswitch sensor used is a solid state microswitch with no mechanical contacts The plunger operates a Hall effect sensor triggering the transistorized output Digital Input Block Diagram of Microswitch Voltage Regulator 1K8 Hall Effect Sensor o + - Trigger Circuit and Amplifier V+ (User) s 0V Opto-isolator Squeegee/ProFlow Home Microswitch Figure 36-17 Microswitch Sensor and Schematic Testing/ Adjustment Testing can be carried out with the microswitch in circuit by measuring the voltage between pin (signal) and pin (0V), Voltage Diagram figure below, refers Released Depressed Released Switch Position 12V Voltage Output at Pin (signal) 0V Figure 36-18 Voltage Diagram 36.14 Technical Reference Manual Chapter Issue Jan 08 SENSORS PRESSURE SENSOR PRESSURE SENSOR Description The pressure sensor switch is wired as a normally open (NO) switch which is closed by the air pressure exceeding the set point Pressure Sensor and Gauge NO NC P Common Pressure Sensor Symbol Digital Input V+ (User) 12V 0V 1K8 Opto-isolator 0V (User) Figure 36-19 Pressure Sensor Schematic Chapter Issue Jan 08 Technical Reference Manual 36.15 SENSORS PRESSURE SENSOR Testing/ Adjustment For adjustment refer to the Pneumatic Module Chapter The sensor may be tested either in circuit or disconnected: In circuit • Monitor the voltage at signal DIG IN whilst increasing the pressure from zero using the main regulator As the air pressure exceeds the set point value the voltage is pulled down to 0V Disconnected • Measure continuity across the switch whilst increasing the pressure from zero using the main regulator As the air pressure exceeds the set point value the contacts close Indicated Pressure bar Set Point Contact Continuity Open Circuit Closed Circuit Open Circuit 12V Digital I/P Signal 0V Figure 36-20 Pressure Diagram 36.16 Technical Reference Manual Chapter Issue Jan 08 SENSORS GIANT MAGNETO RESISTIVE SENSOR (GMR) GIANT MAGNETO RESISTIVE SENSOR (GMR) Description The sensor reacts to the magnetic field produced by the magnetic end of the cylinder piston This produces an analogue signal proportional to the piston position, ie the closer the piston to the sensor the larger the analogue signal This analogue signal is fed to the Analogue to Digital Converter (ADC) on the print carriage I/O Node PCB and the digital output is fed via the CAN bus to the NextMove ES card 30 15 GMR Sensor Pneumatic Actuator Paste Level Amplifier Pneumatic Actuator and GMR Sensor GMR Sensor Sig 0V +12V Paste Level Amplifier Output 0.5V - 5V Analog ADC In Digital Out NextMove ES Card CAN Bus M36 Machine Control 0V +12V Power Distribution PCB Print Carriage I/O Node M37 Power Supply Crate Figure 36-21 Giant Magneto Resistive Schematic Testing/ Adjustment Chapter Issue Jan 08 The sensor does not require adjustment In use the assembly is calibrated see the ProFlow Module Chapter for details Technical Reference Manual 36.17 SENSORS STRAIN GAUGE SENSOR STRAIN GAUGE SENSOR Description The sensors are produced in a full resistive Wheatstone bridge configuration that is temperature and creep compensated It uses a thin foil as one of the resistive elements of the bridge If a force is applied (weight) such that the measuring foil is stretched, the lengthening of the foil causes its resistance to vary This change in resistance is detected and passed to a high gain DC amplifier Solvent Level Strain Gauge Squeegee Strain Gauge PC Single Board Computer (SBC) USB NextMove ES (I/O Node 1) CAN Bus I/Ps Squeegee Pressure Load Cell Print Carriage I/O Node 0V +V -IN +IN CAN In O/Ps NextMove Interface AN IN0 + AN IN0 0V USR +12V -12V Solvent Level Amp Solvent Load Cell -V +V -IN +IN M36 Machine Control Enclosure Testing/ Adjustment 36.18 The sensors not require adjustment In use the assemblies are calibrated see the Squeegee chapter or the relevant underscreen cleaner chapter for details Technical Reference Manual Chapter Issue Jan 08 SENSORS TEMPERATURE AND HUMIDITY SENSOR TEMPERATURE AND HUMIDITY SENSOR The temperature and humidity sensor is an integral part of the print carriage I/O Node PCB and as such there is no adjustment and setting available for this sensor Chapter Issue Jan 08 Technical Reference Manual 36.19 SENSORS TEMPERATURE AND HUMIDITY SENSOR 36.20 Technical Reference Manual Chapter Issue Jan 08 ... 0V Figure 36-4 Voltage Diagram Chapter Issue Jan 08 Technical Reference Manual 36.3 SENSORS OPTO SENSORS OPTO SENSORS Background Suppressed Opto The background suppressed opto sensor is a diffuse... diagnostics at the MMI Analogue Sensors Sensor Location 36.2 The machine uses the following types of analogue sensor: • Giant Magneto Resistive Sensor • Strain Gauge Sensors • Temperature and Humidity.. .SENSORS INTRODUCTION Conventional Switches The machine uses the following types of conventional switch sensors: • Reed Switch • Safety Switch • Microswitch