SENSORS & SYSTEMS. Authority in Displacement Measurement. Non-Contact Displacement and Thickness Measuring. Instruction Manual

Transcription

1 SENSORS & SYSTEMS Authority in Displacement Measurement C O Non-Contact Displacement and Thickness Measuring Instruction Manual optoncdt 2401/2402

2 MICRO-EPSILON MESSTECHNIK GmbH & Co. KG Königbacher Strasse 15 D Ortenburg Tel / Fax / info@micro-epsilon.de Certificated acc. to DIN EN ISO 9001: 2008 V1.2

3 Contents 1. Safety Symbols Used Warnings Notes on CE Identification Proper Use Proper Environment Functional Principle, Technical Data Short Description Measurement Principle Glossary Typical Applications Sensor Control Elements Controller Light Source Technical Data IFS Technical Data IFS Delivery Supplied Items Storage Installation and Assembly Mounting and Dimensions of Sensors Start of Measuring Range Circumferential Clamping Sensor Cable Controller Dimensions Electrical Connections Power supply RS232/RS422 Interface USB Interface Analog Output Synchronization Digital I/O, Encoder Operation Commissioning Displacement Measuring Thickness Measurement Acquiring the Dark Signal Analog Output Adjustment of the LED Brightness Adjustment of the Measuring Rate Light Intensity Synchronized Controller and Encoder Data Triggering Trigger Modes Trigger Input Start Trigger Level Trigger Edge Trigger Latch Trigger Software Trigger Maximum Trigger Frequency Response Time Double Frequency Serial Interface Data Format Command Syntax... 32

4 6.3 Data Transmission Formats ASCII Binary Transmitted Data Available Data Meaning of the Data Data Selection Data Decoding Displacement Measuring Mode Thickness Measuring Mode Decoding the Barycenter Values Decoding the State Data Commands Sensor Selection Measuring Rate Displacement and Thickness Measurement Analog Output Dark Signal Fast Dark Signal Refractive Index Light Source Brightness Averaging Spectral Averaging Hold Last Valid Value Trigger Functions Get Controller Configuration Detection Threshold Light Source Test Auto-adaptive Dark Signal Auto-adaptive Light Source Brightness First Signal Maximum Watchdog Save the Controller Configuration Serial Number, Software Version Reset Encoder Counter Setting the Zero Values Missing Signal in Thickness Measurement Mode Selection Light Source Switch on Double Frequency Select Frequencies for Double Frequency Transmitted Intensity in Double Frequency Mode Command List HyperTerminal IFD2401 Tool Preparation for Measurements Installation Working with the IFD2401 Tool Elements in the Main Window Interface CCD Displacement Measuring Thickness Measuring Warranty Decommissioning, Disposal Troubleshooting Reset to Factory Setting Maintenance... 62

5 Safety 1. Safety The handling of the system assumes knowledge of the instruction manual. 1.1 Symbols Used The following symbols are used in this instruction manual: DANGER! - imminent danger WARNING! - possible dangerous situation IMPORTANT! - application tips and information 1.2 Warnings Avoid banging and knocking the sensor and the controller > Damage or destruction of the sensor and/or the controller Power supply must be connected in accordance with the safety regulations for electrical equipment > Damage or destruction of the controller Protect the cables against damage > Failure of the measuring device Protect the ends of the sensor cable (fibre optics) against pollution > Failure of the measuring device Sensor and controller are matched together. Do not interchange > Loss of specified technical data 1.3 Notes on CE Identification The following applies to the Series 2401/2402 optoncdt measurement system: EMC regulation 2004/108/EC Products which carry the CE mark satisfy the requirements of the EMC regulation 2004/108/EC "Electromagnetic Compatibility" and the European standards (EN) listed therein. The EC declaration of conformity is kept available according to EC regulation, article 10 by the authorities responsible at MICRO-EPSILON MESSTECHNIK GmbH & Co KG Königbacher Straße 15 D Ortenburg The system is designed for use in industry and to satisfy the requirements of the standards EN : 2007 EN : 2005 The systems satisfy the requirements if they comply with the regulations described in the operating manual for installation and operation. 5

6 Safety 1.4 Proper Use The series 2401/2402 measuring system is designed for use in industrial areas. It is used - for measuring displacement, distance and thickness - for in-process quality control and dimensional testing The measuring system may only be operated within the limits specified in the technical data (chap. 2.8 and 2.9). The system should only be used in such a way that in case of malfunctions or failure personnel or machinery are not endangered. Additional precautions for safety and damage prevention must be taken for safety-related applications. 1.5 Proper Environment Protection class sensor: IP40 (Only with sensor cable connected) Protection class controller: IP40 Lenses are excluded from protection class. Contamination of the lenses leads to impairment or failure of the function. Operating temperature: C Storage temperature: C WICHTIG! The protection class is limited to water (no penetrating liquids or similar). Humidity: Pressure: 5-95 % (not condensing) atmospheric pressure EMC: acc. EN : 2007 EN :

7 Functional Principle, Technical Data 2. Functional Principle, Technical Data 2.1 Short Description The /2402 consists of a sensor and controller which are connected with a fibre-optic sensor cable. The sensor is totally passive, since it incorporates no heat sources or moving parts, thus avoiding any thermal expansion which could affect the accuracy of the sensor measuring process. Certain precautions are necessary when handling the fibre-optic sensor cable which connects the sensor to the controller, such as avoiding bending the fibre to a radius of curvature of less than 30 mm. Moreover, the operator must ensure that the ends of the fibre are at all times either connected to the sensor and the controller, or are fitted with their protective caps, in order to avoid any possibility of contaminating the tips of the fibre. The controller incorporates a LED light source and converts the light signals received from sensor, calculates distances via its on-board DSP processor, as well as providing display and data transmission functions via the RS232 or USB link or via the 0 10 V analog output. Controller DSP RS232/422 and USB Polychromatic Light Source Spectrometer DA- Converter Analog output Fibre-optic Connector Sensor Fig. 2.1: Block diagram optoncdt 2401/2402 7

8 Functional Principle, Technical Data 2.2 Measurement Principle Polychromatic white light is focused onto the target surface by a multi-lens optical system.the lenses are arranged such that the white light is dispersed into a monochromatic light by controlled chromatic deviation. A certain distance is assigned to each wavelength by a factory calibration. Only the wavelength which is exactly focussed on the target is used for the measurement. This light reflected from the target surface is passed via a confocal aperture to the receiver which detects and processes the spectral changes. This unique measuring principle enables displacements and distances to be measured with high precision. Both diffuse and specular surfaces can be measured. With transparent materials a one sided thickness measurement can be accomplished along with the distance measurement. Since the emitter and receiver are arranged in one axis, shadowing is avoided. IMPORTANT! Sensor and controller are matched together. Due to excellent resolution and small spot diameters surface structures can be measured. Note that measurement incertainly may occur, if the structure dimensions are similar to the spot diameter, or if the acceptable tilt on a structure, e.g. turning rill, is exceeded. 2.3 Glossary SMR Start of measuring range. Minimum distance between sensor front and measuring object MMR Midrange EMR End of measuring range (Start of measuring range + measuring range). Maximum distance between sensor front and measuring object. MR Measuring range 10 Signal 5 0 SMR MMR EMR Displacement Measuring Range (MR) Sensor SMR Measuring object Fig. 2.2: Measuring range and controller output signal 2.4 Typical Applications Measure profiles or surface topographies, when the sensor is combined with a 3D measurement station, Measure surface reflectivities in which case the sensor behaves like a microscope, but provides the advantage of greater depth of field, Measure thickness (from a few tens of microns to several millimetres) of transparent materials. 8

9 Functional Principle, Technical Data 2.5 Sensor The sensors are interchangeable: the same controller can store up to 20 different calibration tables corresponding to different sensors. The sensor is totally passive, since it incorporates no heat sources or moving parts, thus avoiding any thermal expansion which could affect the accuracy of the measuring process. IMPORTANT! Protect the ends of the sensor cable (fibre optics) and the sensor lens against pollution. 2.6 Control Elements Controller On / Off Switch RS232/422 interface USB interface LEDs Digital I/O (encoder) Sensor input Power supply External light source Analog output, Synchronization Reset Analog output Dark signal acquisition Fig. 2.3: Front view controller LEDs on the controller Error Red Orange Off Light source test fails Data overflow error, data non-evaluable No error Intensity Off Single frequency mode No signal Double frequency mode No signal Red Signal saturated Signal saturated for both frequencies Green Signal intensity is comfortable Signal intensity is comfortable Orange Signal intensity is low No relevance Measure Off Green Orange No measuring object or outside the measuring range Measuring object in midrange (between 15 and 85 % FSO) Measuring object at the intermediate zone of the measuring range (between 0 and 15 % FSO or 85 and 100 % FSO) 9

10 Functional Principle, Technical Data 2.7 Light Source The controller is equipped with an LED as internal light source. An external light source can optionally be connected through the Ext. light source input, see Fig LED Halogen Xenon Type Internal External External Measuring range Normal Extended Normal Light level adjustment Command No Hardware The controller features an automatic test of the light source. The Error LED turns RED when the LED or the lamp should be replaced. The light source test may be enabled or disabled by command (see Chap ). 2.8 Technical Data IFS2401 Modell (standard) IFS IFS IFS IFS IFS IFS IFS (01) IFS Measuring range mm IFS Start of measuring range mm (ca.) Spot diameter μm Linearity Resolution μm % FSO ± 0.1 ± 0.05 ± ± 0.05 μm ~ ~1 ~0.9 % FSO Sensor 0.20 kg 0.22 kg 0.22 kg 0.16 kg 0.19 kg 0.68 kg 3.0 kg 0.52 kg 0.19 kg Weight Sensor + MA kg 0.40 kg 0.40 kg 0.34 kg 0.37 kg 0.90 kg *** 0.76 kg 0.37 kg Max. allowed angle of reflection in direct reflection ± 43 ± 28 ± 27 ± 22 ± 14 ± 14 ± 20 ± 5 ± 8.5 Measuring rate selectable from 100 Hz up to 2000 Hz Ambient light 30,000 lx Light source LED Protection class (sensor/controller) IP 40 Temperature stability (sensor) 0.01 % FSO / C Operation temperature +10 up to +50 C Storage temperature -30 C up to 70 C Output 2x 0-10 V (15 Bit) / RS 232 / RS 422 / USB 2.0 Versorgung 24 VDC Sensor cable (fiber optic cable) Controller Dimensions Functions standard 3 m option up to 50 m bending radius: 30 mm (static), 40 mm (dynamic) (W x H x D): 168 x 138 x mm (6.61 x 5.43 x 4.39 inches) functions: touch keys, trigger, synchronization, storage of up to 20 configurations (for sensors with different ranges) Electromagnetic compatibility (EMC) according to EN : 2007 and EN : 2005 FSO = Full Scale Output All data based on constant ambient temperature during measurement against an 'optical flat' glas target in direct reflection. 10

11 Functional Principle, Technical Data 2.9 Technical Data IFS2402 Model (standard) IFS IFS IFS 2402/ IFS IFS 2402/90-4 IFS IFS 2402/90-10 Measuring range Start of measuring range Spot diameter Linearity Resolution 400 μm 1.5 mm 1.5 mm 3.5 mm 2.5 mm 6.5 mm 6.5 mm approx. 1.5 mm 0.9 mm 2.5 mm 1) 1.9 mm 2.5 mm 1) 2.5 mm 3.5 mm 1) 10 μm 20 μm 20 μm 20 μm 20 μm 100 μm 100 μm ~0.3 μm 1.2 μm 1.2 μm ~3.0 μm 2.0 μm 13 μm 13 μm ± 0.08 % FSO ± 0.2 % FSO μm 0.06 μm 0.06 μm 0.14 μm 0.10 μm 0.7 μm 0.7 μm % FSO 0.01 % FSO Weight Max. allowed angle of reflection in direct reflection Measuring rate Ambient light Light source Protection class (sensor/controller) Operation temperature Storage temperature Output Supply Sensor cable (fiber optic cable) Controller Electromagnetic compatibility (EMC) 50 g ± 8 ± 5 ± 5 ± 3 ± 3 ± 1.5 ± 1.5 selectable from 100 Hz up to 2000 Hz, optional 30 khz lx LED IP up to +50 C -30 C up to 70 C 2x 0-10 V (15 bit) / RS 232 / RS 422 / USB VDC integral cable: standard 2 m option up to 50 m bending radius: 30 mm (static), 40 mm (dynamic) dimensions (W x H x D):168 x 138 x mm (6.61 x 5.43 x 4.39 inches) functions: touch keys, trigger, synchronization, storage of up to 20 configurations (for sensors with different ranges) according to EN : 2007 and EN : 2005 FSO = Full Scale Output 1) Start of measuring range (SMR) measured from sensor axis All data based on constant ambient temperature during measurement against an 'optical flat' glass target in direct reflection. 11

12 Delivery 3. Delivery 3.1 Supplied Items 1 Sensor 1 Sensor cable 1 Controller 1 Test log 1 Instruction manual Once unpacked, check immediately for completeness and transit damage. If damage is found or the shipment is incomplete, please contact the manufacturer or supplier immediately. 3.2 Storage Storage temperature: Relative humidit: -30 to +70 C (-22 F to +158 F) 5 to 95 % (non-condensing) 4. Installation and Assembly The sensors of the series IFS240x are optical sensors, which are used to measure in μm-range. Be careful in mounting and installation! Connect the controller to a power supply (+24 VDC) External light source: If your sensor is equipped with an external light source, connect the light box to the Ext. light source socket located on the controller front panel using the illuminator optical fiber. IMPORTANT! Handle optical sensors with care. The light beam must be directed perpendicular onto the surface of the target to avoid measuring errors. Sensor Sensor cable Controller Wiring Power supply Analog evaluation device Industrial PC USB/RS232/RS422 12

13 Installation and Assembly 4.1 Mounting and Dimensions of Sensors Mounting area 0.12 (.005) SMR 3.4 (.13) ø27 1 (1.06) ø20 (.79) 28 (1.10) 37.6 (1.48) (8.61) ø6 (.24) ø20.3 (.80) SMR 9.9 (.39) 0.3 (.01) Mounting area 8.3 (.33) ø27 1 (1.06) ø20 (.79) 28 (1.10) 37.6 (1.48) (7.02) ø11 (.43) ø23.6 (.80) 1 (.04) SMR10.0 (.39) Mounting area 8.3 (.33) ø27 1 (1.06) ø20 (.79) 28 (1.10) 37.6 (1.48) (6.93) ø11 (.43) ø23.6 (.80) 3 (.12) SMR 16.3 (.64) 8.3 (.33) Mounting area Legend: mm (inches) ø27 1 (1.06) ø20 (.79) 28 (1.10) 37.6 (1.48) (5.73) ø11 (.43) ø23.6 (.80) IFS2401-0,12 IFS2401-0,4 IFS IFS ø32 (1.26) ø27 (1.06) ø27 1 (1.06) ø20 (.79) ø27 1 (1.06) ø20 (.79) 10 (.39) SMR 27.0 (1.06) Mounting area 8.3 (.33) 28 (1.10) 37.6 (1.48) ø11 (.43) ø23.6 (.80) IFS (5.73) 22 (.87) SMR 20.2 (.80) Mounting area 28 (1.10) 37.6 (1.48) IFS (5.98) ø8 (.31) (7.54) (5.87) (4.16) Mounting area SMR 67.0 (2.64) ø50.0 (1.97) ø28.3 (1.11) (6.79) 59.7 (2.35) 57.5 (2.26) Mounting area SMR 213 (8.39) +0.2 ø (2.32) ø45 (1.77) Not to scale SMR = Start of measuring range 1) Tolerances of the mounting diameter: +0.2 / -0.1 mm 8.5 (.33) IFS (.94) IFS

14 Installation and Assembly Continuation dimensional drawings of the sensors 197 (7.75) 4x M4x10 SMR63 (2.48) 167 (6.57) 95 (3.74) 62 (2.44) Lens ø1.8 (.07) 20 (.78) 45 (1.77) 21 (.82) 15 (.59) -0,15-0,10 20 (.78) 30 (1.18) +0, ,05 (1.57) (5.22) 34.4 (1.35) IFS (01) Fiber-optic ø2.1 (.08) Bend protection and cord grip Titanium housing +0 ø4-0.2 (.16) Titanium housing SMR 68 (2.68) 15 (.59) Fiber-optic 2.1 (.08) Bend protection and cord grip 6.25 (.25) 3 (.12) (.08) 15 (.59) 69±0.1 (2.72±.004) 4 (.16) Mounting area 2.5 (0.1) (2.88) MR SMR MR 2 (.08) IFS2402-0,4/1,5/4/10 IFS2402/90-1,5/4/10 14

15 Installation and Assembly Start of Measuring Range For each sensor a minimum distance to the measurement object must be maintained. Sensor SMR Measuring object Fig. 4.3: Start of measuring range (SMR), the smallest distance between sensor face and measuring object. Sensor FS ,12 Start of measuring range 3.4 (.13 I ) Sensor FS ,4 Start of measuring range 1.5 (.06 I ) Legend: mm (inches) I FS ,4 9.9 (.39) I FS (.39) I FS (.64) I FS (1.06) I FS (2.64) I FS (.80) I FS (8.39) I FS ,5 0.9 (.04) I FS 2402/90-1,5 0.5 (.02) I FS (.07) I FS 2402/ (.02) I FS (.10) I FS 2402/ (.06) Not to scale Circumferential Clamping The IFS 240x sensors can be mounted with a mounting adapter. This type of sensor mounting offers maximum reliability because the sensor is clamped around its cylindrical housing. It is absolutely necessary in difficult installation environments, e.g. on machines, production plants etc. 30 (1.18) 23 (.91) 20 (.79) 10 (.39) 30 (1.18) 13 (.51) MA2400 for sensors 2400/2401 consisting of a mounting block and a mounting ring 7 (.28) M5x0.8-6H 10 (.39) Sensor IFS with mounting adapter Mounting ring Dimension A Dimension B Sensor M A ø 27 (1.06) ø46 (1.81) IFS 2401-x M A ø 50 (1.97) ø66 (2.60) IFS M A ø 59 (2.32) ø75 (2.95) IFS B Fig. 4.1a: Circumferential clamping with MA2400 A 22 (.87) 22 (.87) 3 (.12) 3 (.12) 1.5±0.1 4 (.16) 2x M4 7.5 (.30) 11 (.43) Dia. 4 H9 Dia. ø3.4 3 (.12) 12 (.47) 5 (.20) 4.5 (.18) 3x M4 Dia. 8 4 (.16) 4.5 (.18) 15 (.59) MA2402 for sensors (.79) Fig. 4.1b: Circumferential clamping with MA2402 Tolerances 4 H9: +30 μm 0 15

16 Installation and Assembly 4.2 Sensor Cable The sensor and controller are connected with a fiber optic cable. Sensor cables with 50 m (164 ft) length are possible. The user may not shorten or lengthen these fiber optic cables. Usually, a damaged cable can not be repaired. Avoid strictly - any soiling of the connectors, - mechanical load, - strong bendings of the cable. Minimum bending radius: 30 mm (singular) 40 mm (regular). IMPORTANT! Remove the protective cap on the sensor cable only directly before the assembly in the sensor. This avoids a contamination of the optical path. Mounting steps: - Loose the protective sleeve at the sensor. - Lead the sensor cable through the protective sleeve. - Remove the protective cap on the sensor cable and keep it. - Lead the locking pin at the sensor cable into the cavity at the sensor. - Screw together sensor cable and sensor. - Screw the protective sleeve on the sensor. Then connect the fiber optic cable to the controller taking care for correct orientation of the cable connector. To disconnect sensor cable: To remove the optical fiber from its socket first press on the locking lever, then pull the connector. 16

17 Installation and Assembly 4.3 Controller Dimensions When mounting the controller keep the touch keys, connectors and LEDs free for watching! 168 (6.61) 162 (6.38) (4.39) opto NCDT (5.04) 138 (5.43) Fig. 4.4: Dimensioned drawing of the controller 4.4 Electrical Connections Power Supply Connect the controller with a power supply (24 VDC/1A). Use the connector on the front side of the controller, see Fig If your controller is equipped with an external light source, connect the light source to a mains socket. Fig. 4.5: Connectors for power supply DC24 V (+) GND RS232/RS422 Interface The same connector is used for the RS232 or RS422 interface. The configuration is done through the 12-pole socket. For RS422 operation connect pin "5V (+)" and "RS422", see Fig Do not connect pin "5V (+)" and "RS422" for RS232 operation. RS 232 RS 422 USB The RS232/RS422 connector is a RJ11 type connector. Fig. 4.6: Controller with configured RS422 5V (+) RS

18 Installation and Assembly Pin Name Description 3 RX Receiver 4 GND Ground 5 TX Transceiver Tab. 4.1: Pin assignment RS232 Pin Name Description 2 RX - Receiver - (differential input) 3 RX + Receiver + (differential input) 4 GND Ground 5 TX + Transceiver + (differential output) 6 TX - Transceiver - (differential output) Tab. 4.2: Pin assignment RS USB Interface The USB 2.0 connector, see Fig. 4.6, is a standard B-type connector. An USB 2.0 highspeed compliant cable is required. USB 2.0 works with a transmission rate of circa 40 MBits/s. Go to and then IFC Tool for an USB driver, see chap also. IMPORTANT! Interface with USB 2.0 required Analog Output The two V analog outputs are connected to the 12-pole socket, see Fig Output 1: Pin 5 and Pin 6 (left to right) Output 2: Pin 7 and Pin 8 (left to right) The Zero button may be used to set the analog output to zero level. Fig. 4.7: Analog outputs Zero AN. OUT 1 GND AN. OUT 2 GND Synchronization Input and output for synchronization are connected to the 12-pole socket, see Fig Characteristics: TTL, V Pin 1: Sync in (input synchronization) Pin 2: GND (ground) Pin 3: Sync out (output synchronization) Pin 4: GND (ground) Fig. 4.8: Connectors for synchronization SYNC IN GND SYNC OUT GND 18

19 Installation and Assembly The "Sync out" signal is a TTL signal with measurement rate, which is permanently available and which does not require any special configuration. One "Sync out" pulse is emitted for each data point measured. Irrespective of the measuring rate, the "Sync out" goes high at the end of the exposure time. Exposure time Sync out 10 μs Fig. 4.9: Timing of the "Sync out" signal Digital I/O, Encoder Up to three encoders can be connected to the 20-pole Digital I/O connector, see Fig Connector type: MDR. Fig. 4.10: Connector for encoders Pin Description Color encoder cable IFC2401/ Ground blue 2 A+, Encoder 1 white 3 B+, Encoder 1 brown 4 A+, Encoder 2 green 5 B+, Encoder 2 yellow 6 A+, Encoder 3 grey 7 B+, Encoder 3 pink VDC red Tab. 4.3: Pin assignment Digital I/O Pin 8 up to Pin 19 are not connected on the Digital I/O. 19

20 Electrical signal is a single ended TTL level (+5 V) referenced to GND. Track A and B of a single encoder are connected to A+ and B+ with common GND1. Max pulse frequency 2.5 Mhz. Counting pulses: Track A and B allow the detection of direction, therefore the encoder pulse can increase or decrease the counter value. The encoder pulses are not counted as quadrature but as single pulse. The count value is increased or decreased with each new pulse of track A. In order to map the encoder value with a sensor reading, the counter is updated for a valid signal during 50 % of the exposure of the sensor. Max possible counter value before overflow: 2^30 (1,073,741,824) The counter value can be preloaded with the $RCD command to 536,870,912. Data format: Each encoder reading can be selected as a transmitted data package. In binary format a data package consists of 2 bytes as minimum separated by a 0xFF delimiter (0xFF twice). A data package is always sent with the High Byte before the Low Byte. Since the counter value can reach 2^30, each encoder value is transferred as 2 packages of a 15bit word. ( low word before high word, see Chap.6.4.1) 20

21 Operation 5. Operation 5.1 Commissioning - Connect the controller with a power supply, siehe Chp Connect sensor and controller with the sensor cable (fibre-optic cable). - Switch on the unit by operating the "Power" switch (see Fig. 2.3). Startup procedure lasts about 10 seconds. The LED indicators on the front side of the controller go on and off. At the end of the startup, the sensor starts measuring. If you use an external light source switch on the light source first, then the controller. 5.2 Displacement Measuring Position the sensor facing to the target to be measured then slowly advance the sensor (or the target) to reach SMR which corresponds to the sensor being used. As soon as the target enters the measuring range of the sensor the LED "Measure", see Fig. 2.3, on the front panel of the controller indicates it. Important: The distance values increase as the measurement target moves away from the sensor. 5.3 Thickness Measurement In the thickness measuring mode the sensor analyzes two signals reflected from the two surfaces of a transparent measuring object. The controller calculates the intensity and displacement of surface 1 (front face, i.e. the nearest face), the displacement and intensity of surface 2 (rear face), and the thickness. Align the sensor perpendicularly to the object to be measured. Make sure that the measuring object is in midrange (= SMR * MR). As soon as the first surface (displacement 1) is in the measuring range of the sensor the LED "Measure", see Fig. 2.3, on the front panel of the controller indicates it.the LED gives no advice about the attendance of the second surface in the measurement range of the sensor. IMPORTANT! The light beam must be directed perpendicular onto the surface of the target to avoid measuring errors. Please refer to the technical data for the maximum tilt between sensor and measuring object. SMR MR Fig. 5.1: One-sided thickness measurement against transparent materials Minimum measurable thickness of material: 8 % of sensor measuring range Maximum measurable thickness of material: sensor measuring range x material refrective index of measurement material For the calculation of a correct thickness value the controller needs the refractive index of the measuring object. To allow for the spectral variation of the refractive index in the measuring range the controller features refractive index files.the file contains the changing of the refrective index of a known measurement material inside the measuring range. D 1 D 2 Thickness SMR = Start of measuring range MB = Measuring range D 1/2 = Displacement 1/2 IMPORTANT! The controller uses the two strongest peaks for thickness calculation. If one surface is outside the measuring range the controller produces only a signal for the displacement, intensity and barycenter. This can be although too, if a signal is located below the threshold value. In the default setting (see chap ), the controller transmitts for the displacement 1 and the intensity 1 non-zero values. The other data items including thickness are set to zero. 21

22 Operation 5.4 Acquiring the Dark Signal The dark signal of the sensor represents an intrinsic offset level generated by parasitic reflections inside the controller, which must be taken into account for the controller to be able to operate correctly. The level of the dark signal depends on the sampling rate. The dark signal should be acquired at all sampling rates in order to be able to subtract it while the controller is measuring. A dark signal acquisition is performed during adjustment by the manufacturer, but must be repeated at regular intervals. Procedure: - Remove the measuring object from the measuring range or cover the sensor with a piece of paper. - Press the Dark button on the front panel of the controller, see Fig The LED's "Error", "Intensity" and "Measure" start flashing. This operation lasts a few seconds. During this time the sensor records the dark signal. When finished, the 3 LEDs on the front panel of the controller blink on and off simultaneously and show the result of the dark signal measurement. Green: Well dark signal Orange: Dark signal level is too high at low measuring rates, but it is still possible to measure at higher measuring rates Red: Dark signal level is too high at all measuring rates. - Remove the piece of paper. The sensor can be used in the normal way. High dark signal If the color of the blinking LED is orange or red, on completion of the dark signal acquisition sequence this means that the acquired dark signal is too high. This is generally caused by one of the following reasons: - Light was not completely blanked off during the entire operation. In this case, apply a piece of paper over the sensor and repeat the operation. - The light level of the used external light source is too high for working with low measuring rates. In this case you may adjust the light source light level. IMPORTANT! For each measuring rate the dark signal must be measured for the first time. IMPORTANT! In order to perform a dark signal acquisition, it is essential that there is nothing within the measuring range or even better to blank off the light beam by applying a piece of paper over the sensor. IMPORTANT! The controller needs a warm-up time of at least 15 min. before acquiring the dark signal. 5.5 Analog Output The controller features two analog outputs ( V) located on the 12-pole socket, see Fig Both outputs are fully configurable by the operator (see Chap ). The values were coded with 15 bits internally and output via a DA- converter. The outputs feature selectively a displacement/thickness measurement or the intensity signal. Use the "Zero" button, see Fig. 4.7, to reset the analog output to 0 V. Move the measuring object to the start of measuring range and press the "Zero" button to stop the relative measurement. Notice: Depending on the measuring mode, see Chap , the data are output on the analog outputs. 22

23 Operation 5.6 Adjustment of the LED Brightness If your sensor is equipped with an external light source, please skip this chapter. The LED brightness may be adjusted by "$LED" command, see Chap Place a piece of white paper in front of the sensor and observe the spot of light emitted by the sensor. Move the paper forward and backward to find the focus plane where the spot brightness is maximal. Use the "$LED0" command to disappear the light spot. The controller features an operation mode ( auto adaptive LED mode) in which the LED brightness is automatically adjusted to the signal level. This mode is described in Chap Adjustment of the Measuring Rate Move the measuring object in midrange, see Fig Adjust the measuring rate so that the signal intensity will be strong but not saturate. For it track the "Intensity" LED, see Fig Single frequency mode Double frequency mode Off No signal No signal Red Signal saturated Signal saturated for both frequencies Green Well signal Well signal Orange Signal intensity is low No relevance If the "Intensity" LED is red, increase the measuring rate. If the "Intensity" LED is orange, reduce the measuring rate. If the signal is saturated at the lowest rate, decrease the LED brightness. Notice: Always set the measuring rate and the LED brightness so that the Intensity LED is green. When the signal is low (orange Intensity LED) or saturated (red Intensity LED) the sensor still measures, but measurement quality may be deteriorated. See Chap for detailed informations on the measuring rate adjustment. 5.8 Light Intensity The controller measures periodically the quantity of light reflected by the measuring object. The result is a percentual value called intensity. Its value depends on several parameters: - Measuring rate controller - The local slope on the measuring object (angle between the optical axis and the normal to the surface at the measured point) - The reflectivity of the sample in subject to the wavelength 0 - The level of light emission of the LED - The brightness of the LED in subject to the wavelength 0 - The response of the photodetector in subject to the wavelength 0 In standard operation mode ( single frequency ) the exposure time is constant so that the observed intensity variations are directly related to the intensity reflected from the sample. In the double frequency mode both factors vary at the same time so that the interpretation of the Intensity data may be difficult. For this reason a new parameter, the normalized intensity is computed. This is an intensity computed for a fixed frequency (the high frequency), so that it is directly related to the sample characteristics. See the chapters 5.12 and 6.28 also. The detected wavelength varies within the measurement range. Thus the intensity 0 measured at a given point on the measuring object varies when the measuring object is moved within the measurement range. For each point in the measuring range, the value of the intensity of the CMOS line varies between 0 % and 100 %. 23

24 Operation Beyond that, the controller is saturated. Saturation is indicated by the "Intensity" LED (red, see Fig. 2.3). The saturation refers to the original signal of the CCD line. In the Double Frequency mode the Intensity LED indicator on the front panel is correlated to the high frequency. Summary - Measurement quality is good when the Intensity LED is green. - If the LED color is red, increase the measuring rate or lower the LED brightness. - If the LED color is orange, lower the measuring rate or increase the LED brightness. 5.9 Synchronized Controller and Encoder Data Synchronization signals and trigger modes are not required for synchronizing the controller with digital encoder readings: This task is performed automatically by the controller. All you need to do is Connect the encoders to the Digital I/O" connector on the front panel as described in Chap Reset each encoder counter by positioning it at the origin point of the motion range and sending the Reset Encoder Counter ( $RCD ) command, see Chap Configure the controller to transmit encoder data as well as data measured by the controller, see Chap Triggering The measurement output is controllable through an external trigger signal (electrical signal in conjunction with a command). Thereby the anaog and digital output is affected. Triggering does not influence the preset measuring rate. The synchronization input, see Fig. 4.8, is used for external triggering. By default, all trigger modes are disabled and the controller transmits data without interruption immediately after startup Trigger Modes The measurement output in trigger mode can be controlled with the flange as well as the level of the trigger signal. Implemented trigger conditions: - Rising edge, - Falling edge, - High level or - Low level. Set the trigger conditions (edge or level) with the "$TRF" command (see Chap ) Trigger Input The "Sync in" input, see Fig. 4.8, is used for triggering with an external signal (TTL characteristics). The duration of the "Sync in" pulses should be at least 1.2 μs. 24

25 Operation Start Trigger The simplest trigger mode is the Start trigger. It is enabled by sending the $TRG command. On receipt of the command, the controlller stands by for the trigger signal at the "Sync in input, see Fig Once the first "Sync in pulse is received, the controller exits the Start trigger mode and resumes to normal operation. Additional "Sync in pulses are simply ignored. If the trigger signal is not sent, the function can be exit with the sign "$". The controller resumes to normal operation. $TRG Sync Analog output Digital output Fig. 5.2: Time schedule of the Start trigger" function Level Trigger In the Start/Stop on State trigger mode, data transmission starts and stops according to the state of the "Sync in signal. Use the "$TRF" command to set the active state. Use the "$CTN" command to stop this trigger mode. $TRN Sync Analog output Digital output Fig. 5.3: Time schedule of the level triggering Edge Trigger The Start/Stop on Edge trigger mode is similar to the Start/Stop on State, with one difference: data transmission starts and stops by successive "Sync in pulses and not by changes in signal state. Use the "$TRF" command to set the active edge. Use the "$TRS0" command to stop this trigger mode. $TRS Sync Analog output Digital output Fig. 5.4: Time schedule of the edge triggering 25

26 Operation Latch Trigger If the Sync in signal is received, the controller transmits the data of a preset number of measured points and stops immediately. If the controller gets the "$TRE0" command, the controller exits the Latch trigger mode and resumes to normal operation. Use the "$CTN" command to stop this trigger mode. $TREn Sync Analog output Digital output Fig. 5.5: Time schedule of the latch triggering Software Trigger The STR command may be used as a software trigger in the TRE and TRS trigger modes. Obviously, the software trigger does not have the temporal precision of the hardware trigger. Note: The command "STR" is not poosible in the mode "TRN". Use the "TRS" mode instead Maximum Trigger Frequency The maximum trigger frequency, so the frequency of "SYNC IN"- pulses, is limited by the time response of controller. The controller needs several cycles for measuring and converting. 1. Exposing: Gathering of arrived light ( Measuring) 2. Reading: Conversion and storing of light signals as digital values 3. Computation f max = Maximum trigger frequency 4. Data transmission M R = Measuring rate Level and Edge Trigger = Internal process time Example Measuring rate = 2000 Hz, T = 0.2 ms, A = 1 (without averaging); E = 1/(2/ )s = Hz f max A T E A N (Computation, data transmission) = Averaging rate = Number of data packets Latch Trigger A Example Measuring rate = 2000 Hz, T = 0.2 ms, N = 5, A = 2; E = 1/((1 + 5 * 2)/ )s = Hz f max 26

27 Operation 5.11 Response Time Exposure Sync Out Encoder reading Reading Computation Analog output i-1 T EXP i-1 i i+1 i+2 i-2 RS232, data transmis-ssion, see $SOD i i+1 i+2 i+3 T RO T RS i-2 i i+1 T SO i-1 i i+1 i-1 T PR i i+2 i+1 i-2 i-1 i i+1 i = Counter T EXP = 1/f f = Measuring rate e <<1 μs T SO = 10 μs T RO = 0.4 ms T PR = 80 μs T RS = Depends on configuration Fig. 5.6: Continuous acquisition, no averaging Exposure i-2 T EXP i-1 i i+1 i+2 T T EXP T EXP Trigger in Sync Out Encoder reading Reading Computation i i+1 T SO i i+1 T RO i i+1 T PR i+2 i Analog output RS232, data transmission, see $SOD T RS i+1 i i+1 Fig. 5.7: Trigger mode "Start", no averaging Exposure Sync Out Encoder reading Reading Computation (i-1) (i) 1 (i) 2 (i) 3 (i+1) 1 (i+1) 2 (i+1) 3 T EXP T RO T PR (i) T SO (i+1) (i-1) 3 (i) 1 (i) 2 (i) 3 (i+1) 1 (i+1) 2 (i+1) 3 (i-1) 2 (i-1) 3 (i) 1 (i) 2 (i) 3 (i+1) 1 (i+1) 2 Analog output (i-2) (i-1) (i) RS232, data transmission, see $SOD T RS T RS Fig. 5.8: Continuous acquisition, averaging = 3 27

28 Operation Exposure Sync Out encoder reading Reading Computation T RO T EXP1 (i-1) (i) T SO (i-1)f2 (i)f1 (i)f2 (i+1)f1 (i+1)f2 (i+2)f1 (i+2)f2 (i-1)f1 (i)f1 (i)f2 (i+1)f1 (i+1)f2 (i+2)f1 (i+2)f2 T EXP2 T PR (i+1) (i+2) (i-1)f2 (i)f1 (i)f2 (i+1)f1 (i+1)f2 (i+2)f1 Analog output (i-2) (i-1) (i) (i+1) RS232, data transmission, see $SOD (i-1) (i) (i+1) T RS Fig. 5.9: Continuous acquisition, no averaging, double frequency T RS T RS Exposure Sync Out Encoder reading Reading Computation (i-1) T RO (i)f1,1 T EXP1 T SO (i-1)f2,2 (i)f1,1 (i)f2,1 (i)f1,2 (i)f2,2 (i+1)f1,1 (i+1)f2,1 (i-1)f1,2 (i)f2,1 T EXP2 (i)f1,2 (i)f2,2 (i+1)f1,2 (i+1)f2,2 (i+1)f1,2 (i+1)f2,2 (i) (i-1)f2,2 (i)f1,1 (i)f2,1 (i)f1,2 (i)f2,2 (i+1)f1,1 (i+1)f2,1 T PR (i+1)f1,2 (i+1) (i+1)f1,2 Analog output (i-2) (i-1) (i) RS232, data transmission, see $SOD (i-1) T RS (i) T RS Fig. 5.10: Continuous acquisition, averaging = 2, double frequency 5.12 Double Frequency In this mode the controller adapts itself in real time to the intensity of the signal received from the sample. This mode is useful for samples characterized by strong, rapid point-to-point reflectivity variations, such as samples composed of highly reflective metallic motifs deposited on glass. For such samples it is difficult to select a measuring rate that is well suited to all measured points, as a rate which gives sufficient intensity from the glass surface will generate saturation on the metallic surface. Another example when the double frequency mode is useful is that of samples comprising deep holes or sharp slope variations. Glass Metal Fig. 5.11: Intensity distribution Intensity IMPORTANT! With the operation modes - Auto-adaptive Dark Signal, and - Auto-adaptive Light Source Brightness the operation mode double frequency is not authorized. Only the query "$DFA? is authorized. 28

29 Operation In the double frequency mode the sensor switches permanently between 2 frequencies - low frequency f1 (long exposure time) and - high frequency f2 (short exposure time). It computes the data independently for each frequency, and then selects, for each measured point, the optimal frequency. The criteria for selecting the optimal frequency are resumed in the following table: Case Low frequency High frequency Selected frequency 1 Saturated Saturated high 2 Saturated Correct measurement high 3 Saturated No measurement low 4 Correct measurement Correct measurement low 5 Correct measurement No measurement low 6 No measurement No measurement high Example: Suppose that f L = 100 Hz (low frequency) and f H = 500 Hz (high frequency). On metallic surfaces the signal at 100 Hz is saturated and the signal at 500 Hz is correct. So the controller selects the high frequency (500 Hz). On glass substrate measurements with 100 Hz are correct but with 500 Hz the signal is too low (no measurement). The controller selects the low frequency. Note that the high frequency is limited to 1850 Hz. Each couple of acquisitions (one with long exposure and the other with short exposure) is called a cycle. The sensor delivers one synchro out signal per cycle. Measured data are transmitted once per cycle on the digital outputs and updated once per cycle on the analog output. The cycle rate f c is given by the relation: 1/f c = 1/f1 + 1/f2 Intensity The intensity measured by the sensor depends, on one hand, on the characteristics of the sample like reflectivity, slope (see Chap. 5.8) and on the other, on the exposure time. In standard operation mode ( single frequency ) the exposure time is constant so that the observed intensity variations are directly related to the intensity of reflected from the sample. In the double frequency mode both factors vary at the same time so that the interpretation of the Intensity data may be difficult. For this reason a new parameter, the normalized intensity is computed. This is an intensity computed for a fixed frequency (the high frequency), so that it is directly related to the sample characteristics. Arrangement: - ILF is the intensity measured for the low frequency - IHF is the intensity measured for the high frequency The following table shows the difference between the raw (standard) intensity and the normalized intensity. Available intensities in «Double Frequency» mode Selected Frequency «Raw» Intensity «Normalized» Intensity Low (f1) ILF ILF * f1/f2 High (f2) IHF IHF By default, the transmitted Intensity data is the Normalized one. This option may be modified using the DFI command. 29

30 Compatibility with other commands/modes This mode is compatible with most other commands and modes, and in particular with - triggering, - averaging and - manual setting of the LED brightness. It is not compatible with - auto-adaptive light source brightness, Chap auto-adaptive dark signal, Chap spectral averaging, Chap fast dark signal, Chap Command Response when the controller is in double frequency mode AAL, ADK, FDK, AVS Not authorized DRK Authorized TRG, TRE, TRN, TRS, TRF Authorized AVR, HLV Authorized LED Authorized Authorized. Variables can be modified during double FRQ, TEX, SRA frequency mode. The controller operates with the new values, if the controller quits the double frequency mode. 6. Serial Interface The controller features two types of serial interfaces for controlling the controller and measurement output. The following chapter describes this possibilities for the RS232/ RS422. The command language, the data transmission format are identical for the two types of serial interfaces. When switched on, the controller transmits data according to the last configuration. On receipt of character "$" the controller stops sending data and waits for the remaining command characters. Each received character (including $) is echoed back. If the command includes parameters, the final "CR" character is echoed as well. When the controller receives a complete command and has completed the corresponding actions, it returns the string ready CRLF and switches back to normal operation. Received command is illegal: response is echo+ invalid code<crlf> Received command is legal put parameter values are illegal: response is echo + not valid<crlf>. Command and its parameters are legal but execution has failed: response is echo + error<crlf>. The "HyperTerminal " program contains a user-friendly surface for serial communication with the controller, see Chap

31 Serial Interface 6.1 Data Format Controller and PC need the same data transmission settings. Transmission rate: As high as possible 1 Data format: 8 data bits, no parity, one stop bit The "Baud rate command sets the baud rate of the controller. Baud rate Function Set/request the controller baud rate Format $BAUn or $BAU? Parameter n = 9600, 19200, 38400, 57600, , or ) The controller offers baud rates up to kbaud. Note that standard PC COM ports (COM1, COM2) are limited to kbaud. Note that this command has no effect on the PC baud rate that should be set independently. Limitation of the baud rate The maximum number of data values inside a frame transmissible simultaneously per measured point via the serial interface depends on the controller measuring rate and on the interface baud rate. As far as possible, the highest baud rate available should be used. The tables below specify the data value transmission capability according to the interface baud rate and the measuring rate. Measuring rate Baud rate Hz Hz _ Hz Hz _ Hz 1 3 Tab. 6.1: Max. number of transmissible data values in ASCII format Measuring rate Baud rate Hz Hz Hz Hz Hz _ Tab. 6.2: Max. number of transmissible data values in binary format Example: If you want to transmit displacement and intensity (2 data values per measured point) at 1000 Hz, use the ASCII mode with a baud rate of at least or use the binary mode with a baud rate of at least In case the number of transmitted packets specified by the "SOD" command exceeds the limit, the Error led turns to orange and the data overflow bit in the State data is set. 31

32 Serial Interface 6.2 Command Syntax - Every command transmitted to the sensor must start by a "$" character. - Every command must end with a "<CRLF>" (carriage return, line feed) sequence. - Command name consists of 3 capital case letters. - When a command has one or more parameters, the parameters come immediately after the command name. - There should be no comma between the name of the command and the first parameter. - When a command includes several parameters, the parameters are separated by commas. - For a query the parameter is replaced by? 6.3 Data Transmission Formats The sensor provides the ASCII format and the binary format for data transmission ASCII ASCII Function Configure the controller to ASCII transmission format Format $ASC Response None In ASCII format, 5 characters (digits) are transmitted for each data value. The data values inside a frame are separated by commas, and the successive frames are separated by <LFCR> sequence. Example: Measuring mode: Thickness Data selected: Thickness, Displacement 1, Displacement 2 The data values inside a frame are identified as A, B, C etc. Frame separation with <LFCR>. The table below shows the first 36 characters transmitted. x x x x x, x x x x x, Thickness - A Data value separation Displacement 1 - A Data value separation x x x x x LF CR x x x x x Displacement 2 - A Frame separation Thickness - B X = digit (0... 9), x x x x x, x x x x x Data value separation Displacement 1 - B Data value separation Displacement 2 - B Tab. 6.3: String of an ASCII data transmission 32

33 Serial Interface Binary Binary Function Configure the controller to binary transmission format Format $BIN Response None Each data value (16 bit data item) transmitted by the controller is coded with two successive bytes (first H-Byte, then L-Byte). Successive frames are separated by two consecutive bytes <0xFF>. The data item is comprised of two consecutive bytes (H-byte/L-byte).The byte is additionally provided with a "0" as MSB. Start 1 7 Bit H-Byte Stop Start 0 7 Bit L-Byte Stop Conversion of the binary data format: For conversion purposes the high and low bytes must be identified, The MSB in the H-Byte deleted and the remaining 15 bits compiled into 15 bit data item. Reception: H-Byte 0 D14 D13 D12 D11 D10 D9 D8 L-Byte D7 D6 D5 D4 D3 D2 D1 D0 Result of conversion: D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Example: Measuring mode: Displacement Selected data: Displacement, Intensity The data values inside a frame are labeled with A, B etc. The table below shows the first 12 bytes transmitted. H-Byte L-Byte H-Byte L-Byte 0xFF 0xFF H-Byte L-Byte H-Byte L-Byte 0xFF 0xFF Displacement - A Intensity - A Frame separation Displacement - B Intensity -B Frame separation Tab. 6.4a: String of a binary data transmission Note: The MSB for a data item can not be 0xFF, because all the data are encoded either with 12 bits or with 15 bits. Thus if three successive 0xFF bytes appear in the data flow, the first 0xFF is necessarily the LSB for a data value and the next two 0xFF constitute the frame separator. Example: Measuring mode: Displacement Selected data: Displacement, Intensity, Encoder 2 The data values inside a frame are labeled with A, B etc. The table below shows the first 12 bytes transmitted. H-Byte L-Byte H-Byte L-Byte H-Byte L-Byte H-Byte L-Byte 0xFF 0xFF H-Byte L-Byte Encoder 2 Encoder 2 Frame Displacement - A Intensity - A Displacement - B lower 15 bit higher 15 bit separation Tab. 6.4b: String of a binary data transmission 33

34 Serial Interface 6.4 Transmitted Data Available Data The controller measures several data values in parallel at each measured point of the measuring object. The table below shows the available data values for both measuring modes. The controller combines the maximum of 16 different data values to a measured point in a frame. Data value index Displacement Thickness measurement 0 Displacement Thickness 1 not used Displacement 1st surface 2 Current LED brightness Displacement 2nd surface 3 Intensity Current LED brightness 4 not used Intensity 1st surface 5 not used Intensity 2nd surface 6 Barycenter Barycenter 1st surface 7 not used Barycenter 2nd surface 8 State State 9 Counter Counter 10 Encoder 1 = lower 15 bit Encoder 1 LSB 11 Encoder 1 = higher 15 bit Encoder 1 MSB 12 Encoder 2 = lower 15 bit Encoder 2 LSB 13 Encoder 2 = higher 15 bit Encoder 2 MSB 14 Encoder 3 = lower 15 bit Encoder 3 LSB 15 Encoder 3 = higher 15 bit Encoder 3 MSB Tab. 6.5: Summary of all available data values Meaning of the Data Measuring mode displacement: - Displacement is the distance between measuring object and sensor less SMR. - Intensity is the signal level as percentage of the dynamic range of the controller. - Barycenter is the position of the spectral peak on the internal photodetector. Measuring mode thickness measurement: - There are two displacement values, two intensity data and two barycenter data for the two surfaces of the measuring object and one thickness value. Surface one is the one closer to the sensor. SMR D = Displacement SMR = Start of measuring range MR = Measuring range D MR The encoder counter data allows reading of digital encoder synchronously with the controller data. The counter, auto-adaptive mode data and state data are described in Chap

35 Serial Interface Data Selection The "Set Digital Output Data" command enables the user to determine the content of a frame to be transmitted. Set Digital Output Data Function Set/request the data to be transmitted $SODn0,n1,n2,n3,n4,n5,n6,n7,n8,n9,n10,n11,n12,n13,n14,n15 Format or $SOD? Ni = 0 (Data are not transmitted) Ni = 1 (Data are transmitted on the RS232/422 interface) Response Ni = 9 (Data are transmitted on the USB interface) i = 0 15 (Index data item) Note: The last null values may be omitted for convenience, e.g. $SOD1,0,0,1,0,0,0,0,0,0,0,0,0,0,0 may be replaced by $SOD1,0,0,1. IMPORTANT! On the RS232/422 interface the transmission capacity depends on the measuring rate and the data format. Before sending the $SOD command, check that the number of data items selected is compatible with these parameters in order to avoid data overflow. Examples: - In the displacement measuring mode the displacement value and the intensity (see Tab. 6.5) should be transmitted for each measured point via the RS232/422 interface. The following command must be sent to the controller: $SOD1,0,0,1,0,0,0,0,0,0,0,0,0,0,0 (or $SOD1,0,0,1). - In the displacement measuring mode the displacement value (see Tab. 6.5) should be transmitted for each measured point via the USB interface. The following command must be sent to the controller: $SOD9,0,0,0,0,0,0,0,0,0,0,0,0,0,0 (or $SOD9). 35

36 Serial Interface 6.5 Data Decoding Displacement Measuring Mode To obtain the displacement in μm, use the following relationship: Displacement (μm) = (Transmitted value : 32767) x MR (μm) Note: The displacement value is encoded with 15 bits ( ) Thickness Measuring Mode To obtain the displacement and thickness in μm, use the following relationships: Thickness (μm) = (Transmitted value : 32767) x MR (μm) x K The transmitted value is already set off against the refractive index. You may change the refractive index with the command $SRI. In order to optimise the output resolution, the displacement data scale in the thickness measuring mode is different than that in the displacement measuring mode. The reason for this difference is that the effective measuring range in thickness measuring mode is multiplied by the refractive index. Note: The thickness value and the displacement values are encoded with 15 bits ( ). IMPORTANT! Default setting for the scale factor K is 2.0. Use the $CEE command to change this value. K 5. Displacement 1st surface (μm) = (Transmitted value : 32767) x MR (μm) x K Displacement 2nd surface (μm) = (Transmitted value : 32767) x MRh (μm) x K The K parameter may be modified. This is required in the rare situation when the refractive index of the sample to be measured is greater than

37 Serial Interface Decoding the Barycenter Values To obtain the position of the barycenter in pixels, use the following relationship: Barycenter = (Transmitted value : BS) + BO The Position of the spectral peak on the photodetector signal is encoded with 15 bits ( ). BS = Barycenter scale BO = Offset Default setting: BS = 32 ($CEB), BO = 520 ($CRB) Decoding the State Data The state data is an aggregate of various flags. Bit Flag Bit Flag 0 HLV barycenter 2nd surface 8 Selected frequency 1 1 HLV barycenter 1st surface 9 Error light source test 2 HLV displacement 2nd surface 10 Data overflow RS232/422 transmission 3 HLV displacement 1st surface 11 4 HLV thickness 12 5 HLV Intensity 2nd surface 13 6 HLV Intensity 1st surface 14 7 Saturation f lag 15 0 Tab. 6.6: State informations from the controller HLV = Hold last value The HLV bits are set if the corresponding data are not measured but hold as last valid value in Hold last value mode. The saturation flag indicates a signal saturation and refers to the original signal of the CCD sequence. It is set at the same time when the Intensity LED color turns to red. 1) The selected frequency flag is significant on double-frequency mode only. 0 indicates that the high frequency was selected, 1 indicates that the low frequency was selected. Note: This bit replaces the Trigger Flip-flop bit of previous versions. The light source test failure flag indicates that the light source should be replaced. Note that this bit is set at the same time as the Error LED turns red. If the light source test is disabled, this bit is always zero. The data overflow flag indicates that the number of transmitted data directed to the RS232/RS422 port exceeds the maximum number of transmissible data. This bit is set at the same time as the Error LED turns orange. Counter Data The counter data is an aid for software developers who wish to check that there is no data loss in their acquisition software. The 15 bit counter is reset each time a trigger command (TRE, TRN, TRS or TRG) is sent. Auto-Adaptive Mode In the auto-adaptive rate mode this data contain the instantaneous LED brightness coded with 8 bits ( ). This may be useful for analyzing the relative intensity of the signal returned from the measuring object as in this mode the intensity data is practically constant. Relative Intensity = Intensity : n n = Auto adaptive mode data value 37

38 Serial Interface 6.6 Commands Sensor Selection The controller may accept up to 20 calibration tables corresponding to 20 different sensors. Before a measurement is performed the controller needs the information which sensor is connected. Function Format Parameter/ Value returned Example Select confocal sensor Set/request the sensor type $SENn or $SEN? n = calibration index, corresponds to a two digit integer between 0 and 19 $SEN05 This command is used to obtain the measurement range of the sensor currently selected. Scale Function Request the currently used measuring range Format $SCA Value returned Measuring range in microns Measuring Rate The measuring rate of the controller may be managed by two methods. - Selection of a preset measuring rate from a list ( Preset Rate ) - Definition of a specific measuring rate ( Free rate or Exposure Time ) The first method, which is simple and easy to use, is recommended for most applications. In this method, the sampling rate is defined by its index. The second method provides greater flexibility in the choice of the measuring rate: The free measuring rate can be specified in Hz, or the exposure time (inverse of the free rate) can be specified in μs. This chapter describes the different methods, followed by some examples. Selecting a preset Measuring Rate The controller provides 5 preset sampling rates. Index Measuring rate (Hz) Exposure time (μs) 00 free rate free exposure time Tab. 6.7: Measuring rates and related exposure times in the controller Function Format Parameter/ Value returned Preset rate Set/request the index of a preset measuring rate $SRAn or $SRA? n = measuring rate, corresponds to a two digit integer between 0 and 5 Note: The "$SRA00" command selects the free measuring rate. The free rate may be set by the Free rate command or by the Exposure time command described below. Free Measuring Rate The Free Rate command is used to set the controller measuring rate to a free value between 100 Hz and 2000 Hz, or to request the value of the free rate. The index of the free rate in the list of preset rates is 00 (see Tab. 6.7). The last value set to the free rate or the exposure time may be later activated by sending $SRA0. 38

39 Serial Interface Note: The controller may modify slightly the specified value of the free rate in order to comply with its internal constraints (the exposure time in μs should be an integer) and returns the real value immediately after the echo. Free rate Function Set/request the value in Hz attributed to the free rate Format $FRQn or $FRQ? Parameter n = value of the free sampling rate, in Hz (5 digit integer between 100 and 2000 Value returned m ( 5 digit integer between 100 and 2000) is the closest rate value m>=n such that the exposure time in μs is an integer Example Command: $FRQ1995 Response: $FRQ Explication: 1996 Hz corresponds to an integer exposure time (501 μs). Exposure Time The Exposure time command is used to set/request the free exposure time in the controller. Specify any integer exposure time between and μs. The free measuring rate is set to /exposure time (μs). Function Format Parameter Exposure time Set/request the exposure time $TEXn or $TEX? n = value of the free exposure time, in μs (5 digit integer between and 10000) Examples The following table contains the commands Preset Rate, Free Rate and Exposure Time alternately used and interrogates the controller to view the results of each command. Command Comment Sensor response $SRA04 Sets the preset measuring rate index to 4 (1000 Hz) $SRA04 <CR> ready $SRA? Interrogates the controller for the index of the current $SRA?04 ready preset measuring rate $FRQ? Interrogates the measuring rate in Hz $FRQ?01000 ready $TEX? Interrogates the exposure time in µs $TEX? = / 1000 $TEX00530 Sets the exposure time to 530 µs $TEX00530 <CR> ready (and sets the measuring rate index to 0) $FRQ? Interrogates the measuring rate in Hz $FRQ? = / 530 $FRA? Interrogates the current measuring rate index $FRA?00 ready $FRQ1995 Sets the free measuring rate to 1995 Hz $FRQ1995 <CR> 1996 The controller selects a close value of 1996 Hz $TEX? Interrogates the exposure time in µs 501 = / 1996 $TEX?00501 $TEX00120 Attempts to set the exposure time to a non-authorized value $TEX120 not valid ready $SRA01 Sets the preset measuring rate index to 1 (100 Hz) $SRA01 <CR> ready This ends the free rate mode $FRQ? Interrogates the measuring rate in Hz $FRQ?00100 ready $SRA00 Sets the measuring rate index to 0 (= free measuring rate) $SRA00 <CR> ready $FRQ? Interrogates the measuring rate in Hz, 1996 Hz is the last value attributed to the free measuring rate $FRQ?1996 Tab. 6.8: Instruction sequence to the controller Befehlsfolge an den Controller and the effects on it 39

40 Serial Interface Displacement and Thickness Measurement This command allocates a measuring mode to the controller. Index Measuring mode 0 Displacement measuring 1 Thickness measuring The "Mode" command is used to set/request the index of the current measuring mode. Mode Function Set/request the current measuring mode Format $MODn or $MOD? Value returned n = measuring mode index (0 or 1) Analog Output Configuring an analog output consists: - specifying the data item (displacement, thickness, intensity etc.) to an output, - output scaling, inverting Analog Output Function Sets the analog output characteristic Format $ANAn,m,p,q Parameter n = ID of Analog output to configure (0 or 1) m = ID of the data item (0 7), see Chap p = Start value for Vmin (0 V) q = End value for Vmax (10 V) Output characteristic p < q p > q Conditions: 0 <= p < q <= measuring range in μm (displacement) 0 <= p < q <= 2 * measuring range in μm (thickness) 0 <= p < q <= 100 (Intensity) Example for displacement measuring mode: $ANA0, 0, 00000, Scaling, 10 V corresponds to data μm Scaling, 0 V corresponds to data 0 = 0 μm Displacement Analog output 1 (AN.OUT1) Analog Output Function Requests the analog output characteristic Format $ANA? Value returned $ANAm0,p0,q0,m1,p1,q1 m0 = Data item, analog output 1 (0 7) p0 = Start value for Vmin (0 V) q0 = End value for Vmax (10 V) m1 = Data item, analog output 2 (0 7) p1 = Start value for Vmin (0 V) q1 = End value for Vmax (10 V) IMPORTANT! Invert analog output: p > q Example: $ANA0, 0, 05000, The command $AVR does not effect the analog output. Example for displacement measuring mode: $ANA?0, 00000, 10000, 3, 00000, ready Scaling, 10 V for the value 100 % Scaling, 0 V for the value 0 % Intensity value on analog output 2 (AN. OUT2) Scaling, 10 V for the value μm Scaling, 0 V for the value 0 Displacement value on analog output 1 (AN. OUT1) 40

41 Serial Interface Dark Signal See Chap. 5.3 to get detailed information on the "Dark Signal" function. This signal depends on the sampling rate: it increases with the exposure time (reciprocal of the sampling rate). Acquiring and saving the dark signal The "Dark" command records and saves the dark signal in the FLASH memory of the controller for all sampling rates in succession. If the level of the dark signal is too high for low rates, the controller returns the index of the lowest measuring rate which is usable (see "Set Sampling rate" command), and lower sampling rates are inhibited. When finished, the controller returns to the last sampling rate used before dark signal acquisition. Dark Function Acquire and save dark signal Format $DRK Value returned Index of the lowest sampling rate usable Getting the minimal rate authorized after dark signal acquisition The "Minimal Rate" command is used to get the minimal measuring rate authorized after last dark operation. Minimal rate Function Get the minimal authorized measuring rate (query only) Format $FRM Value returned Lowest measuring rate in Hz Fast Dark Signal The "Fast Dark" command only refreshes the dark signal for the current measuring rate, without saving the acquisition in the EEPROM. If the dark signal measured is too high, the controller returns a "not valid <CRLF>" string and the previous dark signal continues in use. This command has two optional arguments: - n is an integer indicating the number of successive acquisitions to be averaged in order to obtain the reference dark signal (default value = 40). - m indicates the influence of the acquisitions made on the new reference dark signal according to the formula: New dark signal = (m x reference dark signal + (100 - m) x old dark signal) Function Format Parameter/ Value returned Fast dark Acquire the dark signal for the current measuring rate only without saving in the controller $FDK or $FDKn,m n = averaging factor for dark signal, range 1 99 m = weighting factor, range Returns "Ready" or "Not valid" 41

42 Serial Interface Refractive Index The measuring object refractive index is necessary in the Thickness measuring mode. Setting a constant refractive index Function Set/request the measuring object refractive index Format $SRIx or $SRI? Value returned x = refractive index, up to four decimal digits Example $SRI Selecting a refractive index file Refractive index files are used to describe the variation of refractive index within the measuring range. The Refractive index file command is used to load a previously saved refractive index file. Function Format Parameter Refractive index file Load the refractive index file $INFn n =0: constant refractive index (determined by last SRI command) n = 1 8: ID of an existing refractive index file Value returned s: material name x1,x2: the minimal and maximal refractive index values in the file Command: $INF3 or $INF? Response: $INF3,"BK7", , Example Command: $INF0 Response: $INF0,"CONSTIND", 1.520, IMPORTANT! Refractive index files allow specifying the variation of the refractive index of a given measuring object within the measuring range. The refractive index file names are up to 8 characters long and have the ind suffix. They are generated by measuring a sample whose thickness is known. Note: Note the material name CONSTIND is attributed in case the file ID is Light Source Brightness This command is exclusively possible for users, who do not use an external light source. LED brightness Function Set/request the light source brightness Format $LEDn or $LED? Value returned n = brightness level, range For each frequency there exists a minimal brightness level below which the LED cannot go: Measuring rate Minmal brightness level Maximal brightness level Up to 500 Hz 10 % 100 % 500 Hz 2000 Hz 25 % 100 % $LED0 puts the LED off $LEDX with X minimal level sets the LED to the minimal level $LEDX with X > minimal level sets the LED to level X Averaging The averaging of the measurements by the controller improves the signal noise ratio. When the averaging factor is greater than 1, the controller transmits data in accordance with the following formula: f f T = f S / M T = Data transmission rate f S = Measuring rate M = Averaging factor 42

43 Serial Interface Thus for a measuring rate of 1000 Hz and an averaging factor of 10, the sensor provides 100 measurement points per second. In order to obtain measurements without averaging, set the averaging to 1. Averaging is especially useful for ambitious measuring objects, for which the signal is low even at the minimum measuring rate. Sometimes averaging is used simply to reduce the data transmission rate. The command $AVR does not effect the analog output. Function Format Parameter/ Value returned Data averaging Set/request data averaging $AVRn or $AVR? n = averaging, range IMPORTANT! Do not use high averaging for moving samples. This reduces the transverse resolution and may cause false measurements. IMPORTANT! The controller calculates arithmetic averages Spectral Averaging The averaging is performed on the photodetector signals before processing. Function Format Parameter/ Value returned Spectral averaging Set/request spectral averaging $AVSn or $AVS? n = averaging, range Hold Last Valid Value The Hold last value mode command is useful for measuring objects with a great number of non measurable points, due to large local slopes or due to a very low reflectivity. When measuring such samples it may be convenient that the value delivered for those positions will not be zero. Instead, the sensor sends the last valid value. Note: If a measurement can not be calculated from the given data and the last measured value is transmitted the corresponding "Hold last value" bit in the status data is set. Function Format Parameter/ Value returned Hold last value Set/request max. number of points for "Hold last value mode" $HLVn or $HLV? n = max number of points to hold, range Trigger Functions Start Trigger The "Start Trigger" command switches the controller into standby mode, waiting for a trigger signal at the "Sync in input (see Chap ). As soon as a rising edge or a falling edge 1, whichever has been selected by the Select active edge command is detected at the "Sync in input, the controller starts measuring with a delay of 1 exposure time (exposure time {μs} = /measuring rate) and a repetition time of 1.2 μs. Note: The emission of Sync out signals stops and restarts together with data transmission. 1) Setup by the command "Select active edge" Function Format Start trigger Put the controller on standby pending receipt of an external trigger signal. Upon receipt of the trigger signal, the controller starts measuring at the programmed measuring rate. $TRG 43

44 Serial Interface Following a "Start Trigger" command it is possible to disarm the trigger and restart acquisition without receiving a trigger pulse using the "Continue" command or transmit the string "$" to the controller. Function Format Parameter/ Value returned Continue Disarms the start trigger function and resumes normal operation $CTN None Level Trigger The "Start/stop on state" command switches the controller into standby mode for level triggering, waiting for a trigger signal at the "Sync in input (see Chap ). Data transmission is enabled when the SYNC IN signal is in the active state. The active state (high or low) is determined by the TRF command. Start/stop on state Function Enable/Disable data output through state triggering on the "Sync In" input Format $TRNb Parameter/ b = 1/0 Value returned Pulse rate See Chap Note: On each transition of the Sync in signal from non-active state to active state, the flip flop bit in the state data changes. Edge Trigger The "Start/stop on edge" command switches the controller into standby mode for edge triggering, waiting for a trigger signal at the "Sync in input (see Chap ). Data transmission is enabled and disabled alternatively by successive Sync in pulses. Use the "TRS" command to define the edge characteristics. Start/stop on edge Function Enable/Disable data output through edge triggering on the "Sync In" input Format $TRSb Parameter/ b = 1/0 Value returned Pulse rate See Chap Note: On each second Sync in pulse the flip flop bit in the state data changes. Software Trigger The STR command may be used as a software trigger in the TRE and TRS trigger modes. Obviously, the software trigger does not have the temporal precision of the hardware trigger. Function Format Parameter/ Returned Software trigger Replaces the hardware trigger in the "TRE" or "TRS" modes $STR None Note: In the TRG mode, the $ sign or $CTN command may be used as software trigger. If you wish to use the software trigger avoid the TRN mode. Use the TRS mode instead. 44

45 Serial Interface Latch Trigger The "Latch Trigger" command is similar to the Start trigger command with the following difference: When the Sync in signal is received, the controller transmits the data of a preset number of measured points and stops immediately. Each successive Sync in signal triggers the transmission of a new group of data packets until the mode is disabled with the "Restart acquisition" command. Latch trigger Function Enable/Disable the Latch trigger and determine the number of points to latch. Format $TREn (enable mode) or $TRE0 (disable mode) Parameter/ n = number of points to latch on each "Sync in" pulse, Value returned range: pulse rate see chapter Note: On each Sync in pulse the flip flop bit in the State data changes. Edge or Level Trigger The measurement output in trigger mode can be controlled with the edge as well as the level of the trigger signal. Implemented trigger conditions: - Rising edge, - Falling edge, - High level or - Low level. Active edge/active state Function Determines the active edge for the commands TRG, TRE, TRS Determines which state is active for the TRN command Format $TRFb Parameter/ b = 0 for rising edge and high state Value returned b = 1 for falling edge and low state Get Controller Configuration The Get Setup command is used for interrogating the controller on its current configuration. Get setup Function Request the current configuration Format $STS Value returned String Configuration e.g. in displacement mode, see also Chap : SRA03,MOD0,SEN04,ASC,AVR3,SOD1,0,0,1,ANA0,0,32767,3,0,4095,SCA300 ready Fig. 6.1: Decoded controller configuration Measurement range sensor Analog output, see Fig. 6.2 Data to be transmitted, Chap Averaging Transmission format Sensor type Operation mode Measuring rate 45

46 Serial Interface... ANA Value for 10 VDC, Analog OUT 2 Value for 0 VDC, Analog OUT 2 Intensity, Analog OUT 2 Value for 10 VDC, Analog OUT 1 (End of measuring range) Value for 0 VDC, Analog OUT 1 (Start of measuring range) Displacement, Analog OUT 1 Fig. 6.2: Decoded analog output configuration Detection Threshold This command is used to adjust the detection threshold for the optical signal. This threshold defines the minimum intensity, below which the controller will not detect any signal. By default, this threshold is set to the value If it is known that the intensity of the signal is very low, the detection threshold can be lowered in order to be able to detect very low peaks. In case of false measurements, e.g. measurement when no measuring object is in the measuring range, the detection threshold should be increased. Threshold for displacement measurement Function Format Parameter/ Value returned Detection threshold in distance measuring mode Set/request the threshold $MNPx or $MNP? x between 0 and 1, e.g. $MNP0.03 Threshold for thickness measurement In the thickness measurement mode there are 2 detection thresholds: - Threshold for strong signal peaks - Threshold for weak signal peaks. By default both are set equal, however, depending on measuring object characteristics, it may be necessary to set two distinct values. Note that often the optimal value for the thickness measuring mode detection threshold for the stronger peak is about 50% higher than that of displacement measuring mode. Function Format Parameter/ Value returned Funktion Format Parameter/ Value returned Detection threshold strong peak, thickness Set/request the threshold for strong signal peaks $SPPx or $SPP? x between 0 and 1, e.g. $SPP0.05 Detection threshold weak peak, thickness Set/request the threshold for weak signal peaks $SDPx oder $SDP? x between 0 and 1, e.g. $SDP0.03 SPP applies to the stronger peak (not the nearest) and SDP to the second-strongest peak, so that logically SDP should be smaller than SPP. 46

47 Serial Interface Light Source Test The role of the light source test is to indicate when the light source should be replaced. The series 2401 and 2402 controller use a LED with a very long life time, this test is not required. However MICRO-EPSILON recommends to enable the test for controllers with an external light source. Enable/Disable the light source test Function Format Parameter/ Value returned Activation of the light source test Enable/Disable the light source test $SLPb or $SLP? b = 1 or 0 Threshold level The light source test requires a light-level below which the test fails and the Error LED turns red. The threshold is adjusted using the CSL command. Function Format Parameter/ Value returned Threshold for light source test Set/request the threshold level for the light source test $CSLn or $CSL? n = 0,,, Auto-adaptive Dark Signal In this mode the controller measures automatically the fast dark signal (see also Chap ) and adapts it permanently. To do so, the controller analyses the internal photodetector signal, determines the zone occupied by the signal, and adapts the fast dark signal in all other zones. This mode is particularly useful for external light sources whose brightness varies with temperature and with aging. Function Format Parameter/ Value returned Activation of auto-adaptive dark Enable/disable the auto-adaptive dark signal measuring $ADKb or $ADK? b = 1 or Auto-adaptive Light Source Brightness In this mode the controller adapts automatically the light source brightness to compensate for variations in the level of the signal returned by the measuring object. The LED brightness is modified so as to bring the signal level as close as possible to a preset threshold. Function Format Parameter/ Value returned Auto-adaptive LED Enable/disable the auto-adaptive brightness measuring $AALb or $AAL? b = 1 or 0 47

48 Serial Interface The threshold for this mode is set with the "VTH" command. Function Format Parameter/ Value returned Threshold for auto-adaptive mode Set/request the threshold value for the auto-adaptive light source test $VTHn oder $VTH? n = 0,,, First Signal Maximum Relative maximum or First peak mode is a feature of the displacement measuring mode that is useful for measuring objects whose surface is partially covered with a transparent coating. For such measuring objects the reflection of the surface beneath the coating may be stronger than that from the outer coating surface. In order that the controller detects the first peak (instead of the strongest peak, which it does by default), the First peak mode should be enabled. Function Format Parameter/ Value returned First peak mode Enable/Disable the relative maximum $MSPb or $MSP? b = 0: Maximum b = 1: Relative maximum (First maximum) Intensity First maximum Highest maximum Detection threshold Pixel CCD line Fig. 6.3: First signal maximum 48

49 Behavior of the controller in "Distance" measuring mode Number of peaks above detection threshold Controller behavior when "First peak" mode is enabled 0 Distance = 0.0 Intensity = Distance and intensity corresponding to the single peak detected 2 Distance and intensity corresponding to the first peak (peak generated by the surface that is nearer to the sensor) More than 2 The controller uses the first maximum above the detection threshold. Controller behavior when "First peak" mode is disabled Distance = 0.0 Intensity = 0.0 Distance and intensity corresponding to the single peak detected Distance and intensity corresponding to the strongest peak Distance and intensity corresponding to the strongest peak Behavior of the controller in "Thickness" measuring mode Number of peaks Controller behavior 1 above detection threshold 0 Distance 1 = 0.0, Distance 2 = 0.0 Intensity 1 = 0.0, Intensity 2 = Distance 1 and intensity 1 correspond to the single peak detected. Distance 2 and intensity 2 are, depending on parameter RSP, null or square with distance 1 and intensity 1. 2 Distance 1 and intensity 1 correspond to the nearer peak. Distance 2 and intensity 2 correspond to the further peak. More than 2 First, the sensor selects the two strongest peaks. Distance 1 and intensity 1 correspond to the nearer peak among these 2 peaks Distance 2 and intensity 2 correspond to the further peak among these 2 peaks Detection level Detection threshold is the minimum Intensity level for a peak to be detected. Smaller peaks are considered as noise. Please note that the controller has 3 distinct detection thresholds: Detection threshold for "Distance" measuring mode "Thickness" measuring mode: 1 st peak "Thickness" measuring mode: 2 nd peak Command MNPx SPPx SDPx 1) In the "Thickness" measuring mode the "first peak" mode has no effect. 49

50 Serial Interface Watchdog The controller features a software to detect possible errors, i.e. a permanent test that validates that the controller operates normally. In case it does not, the watchdog resets the controller. This feature is useful for the case the controller is blocked due to an incomplete command or another reason. Activate watchdog Activate watchdog Function Enable/disable the watchdog function Format $WDEb or $WDE? Parameter b = 1 or 0 Watchdog period Function Format Parameter Watchdog period Set/request the watchdog period $WDPn or $WDP? n = watchdog period in seconds Save the Controller Configuration The "Save setup" command is used to save the current configuration of the controller on the non-volatile memory. If this is not done, the next time the controller is switched off the controller will lose all the latest modifications made. Save setup Function Save the current configuration in the controller EEPROM Format $SSU Value returned None IMPORTANT! Use the "Save Setup" command to avoid the controller losing the configuration when the equipment is switched off Serial Number, Software Version Version Function Request the firmware of the controller Format $VER Value returned Serial number, software version Reset Encoder Counter Encoder reading is relative, so it is necessary to reset the counter each time they are powered off and on. This can be done by sending the Reset Encoder Counter command. The reading of the desired counter/s is set to the reset value. Reset value = 2 30 / 2 = Format Parameter Example Reset Encoder Counter $RCDb1,b2,b3 bi = 1, if encoder should be reset $RCD0,1,0 Set the reading of encoder 2 at current position to Note: The reset value is intentionally not 0 because the counter data has to be a positive integer. 50

51 Serial Interface Setting the Zero Values A simplified method for configuring the analog outputs is available using the Set Zero button on the front panel and/or the SOF command. This method may be used to set the 0V-level of both analog outputs to the current value of the data directed to them (the 10V values are kept at the max authorized values, cf. ANA command). Function Format Parameter Example Query Set analog output zero Set/reset the analog output 0 V value $SOFn n = 0: set 0 V values to current values, equal to the "Zero" button n = 1: reset 0 V values, cancels "Zero" button operation $SOF1 (reset 0 V values) Not available Missing Signal in Thickness Measurement Mode If in thickness measurement mode one signal is detected only, this may be due to: - One surface of the measurement object is located outside of the measuring range or - One signal is located below the detection threshold, see chapter too. The command "missing signal" assigns the behavior of the controller in such a case. Option 1 (default setting) 1. Surface Displacement 1, Intensity 1 and Barycenter 1 of measured signal 2. Surface Displacement 2 = Displacement 1, Intensity 2 = Intensity 1 and Barcycenter 2 = Barycenter 1 Result Thickness = 0 Option 2 1. Surface Displacement 1, Intensity 1 and Barycenter 1 of measured signal 2. Surface Displacement 2 = 0, Intensity 2 = 0 and Barycenter 2 = 0 Result Thickness = 0 Missing signal Funktion Assigns the behaviour of controller in the thickness measurement mode, if the sensor detects only one surface Format $RSPb oder $RSP? Parameter/ b = 0: Option 2 Value Returned b = 1: Option 1 51

52 Serial Interface Selection Light Source The command selects between external and internal light source. Funktion Format Parameter Set light source Selection of light source $CCLn or $CCL? n = 0: use the internal light source n = 1: use the external light source Switch on Double Frequency With the operation modes - Auto-adaptive Dark Signal, - Auto-adaptive Light Source Brightness the operation mode double frequency is not authorized. Only the query "$DFA? is authorized. Function Format Parameter/ Value Returned Activate "double frequency" Enable/Disable the "double frequency" mode $DFAb or $DFA? b= 0: "double frequency" off b = 1: "double frequency" on Select Frequencies for Double Frequency The DFF command sets or requests the two frequencies for the "double frequency" mode. Function Format Parameter/ Value Returned "double frequency" frequencies Set/Request the two frequencies for the "double frequency" mode $DFFf1,f2 or $DFF? f1= low frequency f2 = high frequency in Hz Conditions: frm f1 < f Hz, where frm is the minimum authorized rate of the controller Transmitted Intensity in Double Frequency Mode By default, the transmitted Intensity data is the Normalized one. This option may be modified using the DFI command. Function Format Parameter/ Value Returned "double frequency" intensity Select the type of transmitted intensity $DFIb or $DFI? b = 0: normalized intensity b = 1: raw intensity 52

53 Serial Interface 6.7 Command List Command Parameter Description Basic settings AVS Averaging, range Set/request of the spectral averaging AVR Averaging, range Set/request of the data averaging MOD Measuring mode, 0 or 1 Set/request the current measuring mode SEN Sensor-ID, range 1 19 Select the sensor type SCA Measuring range in μm Request the current measuring range used MNP Set/request the displacement threshold MSP b = 1 or 0 Enable/disable the relative maximum SPP Set/request the threshold for strong signal peaks, thickness measurement SDP Set/request the threshold for weak signal peaks, thickness measurement SRA Measuring rate ID 1 Set/request the measuring rate FRQ Measuring rate in Hz 1 Set/request the free measuring rate in Hz TEX Exposure time in μs 1 Set/request the exposure time FRM Minimum measuring rate in Hz Min. authorized measuring rate, query only STS List of parameter values Get the current controller configuration Max. number of points to hold, Hold last value HLV range MSP 0 or 1 Enable/disable the relative maximum RSP 0/1 "Missing signal" in thickness mode Basic functions DRK None Acquire and save dark signal FDKn,m n = averaging, range 1 99 m = weighting, range Acquire the dark signal for the current measuring rate only without saving in the controller Command Parameter Description Basic functions SSU None Saves the current controller settings in the EEPROM VER None Request serial number and software version of the controller RCD b1, b2, b3 bi = 1: reset encoder counter i Reset encoder position Digital I/O SOD $SODn0,n1,n2,n3,n4,n5,n6,n7,n8,n9,n10, n11,n12,n13,n14,n15 or $SOD? Set/request data to be transmitted, transmission channel ASC None ASCII mode BIN None Binary mode BAU Set/request the baud rate CEE Default setting = 2 Thickness measuring mode CEB Default setting = 32 Scale factor barycenter CRB Default setting = 520 Offset barycenter Analog I/O ANA n = Output-ID (0 or 1) Configuration of the analog output m = Data (0 7), see Chap p = Start value for Vmin (0 V) q = End value for Vmax (10 V) SOF n = 0: set 0 V values to current values n = 1: reset 0 V values Set analog output zero 1) Parameter value is limited by the min. authorized measuring rate 53

54 Serial Interface Command Parameter Description Light source SLP b = 1 or 0 Enable/disable light source test CSL n = 0,,, 9999 Set/request the threshold for the light source test LED n = brightness, range Set/request the light source brightness CCL Triggering n = 0: use the internal light source n = 1: use the external light source Selects the light source TRG None Put the controller on standby pending receipt of an external trigger signal. Upon receipt of the trigger signal, the controller starts measuring at the programmed measuring rate TRE n = number of points to latch on each "Sync in" pulse, range: 1 99 Enable/Disable the Latch trigger and determine the number of points to latch TRS b = 1 or 0 Enable/Disable data output through flank control on the "Sync In" input TRN b = 1 or 0 Enable/disable the data output through state control on the "Sync In" input CTN None Stops the trigger function and returns to normal operation mode TRF b = 0 for rising edge and high state b = 1 for falling edge and low state Edge characteristic for the commands TRG, TRE, TRS State characteristic for the TRN command Watchdog WDE b = 1 or 0 Enable/disable watchdog function WDP n = watchdog period in seconds Set/request the time period for the monitoring function Refractive index SRI x = refractive index, up to four decimal places Set/request the a constant refractive index for the measuring object INF s = file name (up to 8 characters, limited with "", without the ".ind" suffix Load a refractive index file Auto-adaptive modes AAL b = 1 or 0 Enable/disable the automatic brightness measuring VTH n = 0,,, 4095 Set/request the threshold for the automatic light source test ADK b = 1 or 0 Enable/disable the automatic dark signal measuring DFA b = 1 or 0 Enable/disable the double frequency mode DFF f1 = low frequency f2 = high frequency Set/request the frequencies for the double frequency mode DFI b = 0 > normalized intensity b = 1 > raw intensity Selects the intensity to be transmitted 54

55 HyperTerminal 6.8 HyperTerminal You can receive data and configure the controller through the RS232 interface with the Windows HyperTerminal. All you need is a free COM port (e.g. COM1) on your PC and the commands described in the foregoing chapters. Preparation Measuring - Connect your controller to a free COM port of the host computer - Start the program HyperTerminal (Menu Start > Programs > Accessory > Communication > HyperTerminal) Type in the name of the connection and click on the "OK" button. Fig. 6.3: Connection establishment with the program HyperTerminal Select the interface and click on the "OK" button. Land/Region: Germany(49) Prefix: 8542 COM2 Fig. 6.4: Definition of the serial interface Define the following interface parameters: Baud rate: Baud Data format: 8 Data bits Parity: None Start / Stopbit: 1 Flow control: No Click on the "OK" button , ,00049 $STS SRA1,MOD0,SEN00,SRC0,ASC,AVR99,SOD1,32767,3,00000,04096,SCA 999 ready 10463, ,00049 _ Fig. 6.5 User interface in terminal operation As soon as the connection is established, the data from the controller are sequentially displayed. If the "$" character is sent, the data output is interrupted and the controller waits for further instructions. Necessarily select a slower measuring rate and increase the averaging rate in terminal use to reduce the data transfer rate. 55

56 IFD2401 Tool 7. IFD2401 Tool The software - transfers parameters to the controller and - transmits measuring results and represent them in a diagram. All data are transmitted through the USB interface and can be saved on demand. 7.1 Preparation for Measurements System requirements The following system requirements are recommended: - Windows 2000 or Windows XP - Pentium III, > 300 MHz MB RAM - USB 2.0 Port Cable and Program Routine Requirements - USB cable - Driver for USB port - Software 7.2 Installation Proceed as follows to start using the demo software: IMPORTANT! The supplied CD contains the driver for the USB port and the software. 1. Switch on the controller. 2. Insert the supplied CD-ROM into the CD-ROM drive of the PC. 3. Connect the controller with a free USB 2.0 Port on your PC. 4. The Windows Assistant for searching for new hardware will start. Select "Install the software automatically (Recommended)" for installation and click on "Next. Fig. 7.1: Windows XP has found a new hardware and starts the hardware wizard. Fig. 7.2: Windows XP copies files from CD You may see the screen during the installation process as Windows XP copies the files from the CD. No user intervention is required. 56

57 IFD2401 Tool Fig. 7.3: The operating system messages the successful installation of the USB driver. The USB Driver has now been installed. Click the "Finish" button to finish the installation. 5. Start the file "IFD2401_Tool_Setup_Vx.x.exe" from the CD-ROM. This installs the software on your PC. 6. Start the software. Menu Start > Programs > IFD2401_Tool_Vx.x. Fig. 7.4: User interface in the displacement measuring mode 57

58 IFD2401 Tool 7.3 Working with the IFD2401 Tool Elements in the Main Window 1 2 Main window: 1 Menu bar: Used to call up all the measuring programs and settings which are available in the software. 2 Options display: Used to launch the individual configuring and measuring programs Interface Contains the substantial interface settings and makes it possible to read the sensor calibration tables stored in the controller. Examine before the start of the measuring program the agreement between sensor respectively range (measuring range) and the connected sensor. Otherwise a correct measurement is not possible. 58

59 IFD2401 Tool CCD Displacement Measuring This program enables you the direct readout of the measurements from the photo-sensitive element (CCD) without previous computation through the controller. The program differentiates between three CCD windows: - Original CCD signal including dark signal units. - Original CCD signal less of dark signal - CCD signal spectrally adjusted less off dark signal. In the distance mode the software evaluates the data, which are currently measured by the. The main view plots the distance information. The program also contains statistics and a data storage. The settings for the measuring program are saved and then reused when the measuring program is started again Thickness Measuring In the thickness mode the software plots the cur-rently measured thickness data of the optoncdt Note that the target refractive index and the detection thresholds (threshold) are a basic condition for an accurate measurement. You will find further informations to the program in the on-line help. 59