Agilent AEDL Series Optical Linear Incremental Encoder Features Description The AEDL Series linear encoders use high technology transmissive optical encoding technique to detect linear motion. There is no mechanical contact between the scanning head and the linear scale, thus eliminating error due to frictions and alignment errors. Basically, the encoder consists of a precision linear glass scale and a scanning head, which translate the linear position into analog and digital electrical signals. The encoder can be easily aligned and installed using the provided spacer-clip and the selfadhesive mounting feature. Using Agilent's Quick StickTM method, the encoder profile can be easily adjusted while the system is aligned to the machine system. The Quick StickTM method provides spacing foam that prevents the encoder profile from sticking to the machine base until the alignment has been performed. A pair of L-pins (setting pins) ensured that the scanning head is fixed at a nominal position while the linear encoder is aligned and mounted to the machine system. With state of the art technologies, Agilent's linear encoders provide an ideal feedback control to high precision motion systems. The linear encoders are available in two colors, silver or black anodized. * Insensitive to dirt/contamination Applications * 0.05 m*, 0.1 m*, 0.5 m, 1 m, 5 m and 10 m resolutions The AEDL Series linear encoder provides linear motion detection, delivering an accurate and insensitive closed-loop control solution. Typical applications: * Large mounting tolerance * Analog or digital output signals * Self-adhesive mounting profile * Simple and easy assembly * 5 - 2200 mm measuring length * Traversing speed of up to 16 m/s * 40 m grating period (pitch) * 3 m or 5 m (per meter) accuracy class * 0 C to +55 C temperature range * XY table positioning * Single 5V supply * high precision machines * Up to 3 m cable length * industrial plotter * high-accuracy measurements * linear motors * robotics * electronics assembly and inspection Note: Agilent Technologies encoders are not recommended for use in safety critical applications, e.g. life support systems and critical care medical equipment. Please contact sales representative if more clarification is needed. ESD WARNING: NORMAL HANDLING PRECAUTIONS SHOULD BE TAKEN TO AVOID STATIC DISCHARGE. Theory of Operation Definitions Agilent Technologies utilizes an ultra collimated LED as the light source for the AEDL linear encoders, where very high modulation can be achieved. A 22-element photodiode array in the scanning head detects the modulated light. A high technology signal-conditioning IC is integrated inside the scanning head. The IC performs real time phase, amplitude and offset signal monitoring, which will correct any deviation from the expected mathematical signal that is caused by environmental influence. Consequently, a high purity sinusoidal signal is available for interpolation process, which is performed in the same IC. A world-class high precision measurement system is thus achieved through Agilent's linear encoders. Resolution: Smallest movement detectable by the encoder. It is normally expressed in units of distance (e.g. 0.5 m or 100nm). Pitch: Also known as grating or optical period, it refers to the distance for a single window-bar pair on the linear scale. Accuracy: A measure of how close the output is to where it should be. It is usually expressed in units of distance over the scale length (e.g. +/3m per meter) or a percent of nominal resolution. Measurement Length (ML): The effective measurement length that the encoder system can be used for. Output incremental signal can be specified as either digital (RS422) or 1 Vpp analog sinusoidal when ordering. Signals of Channel A and Channel B are 90e phaseshifted. Index marks are periodically spaced at a distance of 50 mm, or distance coded at 500 x pitch size*. Fault detection signal is activated when improper operation occurs, such as power cutoff, loss of light source or heavy contamination. This signal can be used to shut down machine operation safely, when a failure occurs. 2 Interpolation: An electronic technique for increasing the resolution from the optical cycles on the linear scale to a higher number of quadrature square waves per unit length. These square waves can then be further quadrature decoded. Quadrature: This term refers to the 90-electrical-degree (1/4 of a cycle) phase relationship between the A and B channels of incremental encoder output. Quadrature Decode: Also known as 4X Decode, it refers to the common practice of counting all 4 quadrature states (or square wave transitions) per cycle of quadrature square waves. Thus, a linear encoder with a cycle width of 40m, for example, has a resolution of 10 m. Index Signal: A once-per-scale output or multiple outputs at certain fixed locations. It is used to establish a reference to a known home or starting position. Also known as reference mark, home, or Z. * Note: 0.05 m and 0.1 m are future options, which are not yet available. The resolutions stated are after interpolation and users' quadrature decoding. Distance-coded version will be available as a future option. Outline Drawing Description A Start of measuring length B Distance between the mounting screw holes C Cable diameter D Overall length of measuring system (ML + 34 mm) E Mounting surface with high strength adhesive tape type TESA 4965 F Output signal (RS422A digital or analog 1 Vpp) G Initial position of scanning head when ready for installation (available on the opposite side upon request) H Mounting surface to machine parts Tape Mounting Version F G H A B C D 3 E Connector Pin Configuration Four options of connector types are available, namely the 12-pin heavy-duty industrial, 15-pin DSub, 9-pin D-Sub or strand wire options. Table 1 shows the pins configuration and cable color for the respective connector types. There are also options of either left or right cable exit for the cable. 12-pin Round Connector PIN Analog (1 VPP) Digital RS 422 Cable color 1 Cosine negative, U2- Channel B negative, Z2- Pink 2 Power supply, +5V Power supply, +5V White/Green 3 Index Positive, U0+ Index positive, Z0+ Red 4 Index negative, U0- Index negative, Z0- Black 5 Sine positive, U1+ Channel A positive, Z1+ Brown 6 Sine negative, U1- Channel A negative, Z1- Green 7 NC Error, active low Purple 8 Cosine positive, U2+ Channel B positive, Z2+ Grey 9 NC Error, active high Yellow 10 0V 0V Brown/Green 11 0V 0V - 12 +5V +5V - Shell Shield Shield - 15-pin D-Sub Connector (male) PIN Analog (1 VPP) Digital RS 422 Cable color 1 NC NC - 2 NC NC - 3 NC Error , active low Purple 4 Index negative, U0- Index negative, Z0- Black 5 Cosine negative, U2- Channel B negative, Z2- Pink 6 Sine negative, U1- Channel A negative, Z1- Green 7 NC NC 8 Power supply, +5V Power supply, +5V White/Green 9 0V 0V Brown/Green 10 NC Switch White 11 NC Error, active high Yellow 12 Index Positive, U0+ Index positive, Z0+ Red 13 Cosine positive, U2+ Channel B positive, Z2+ Grey 14 Sine positive, U1+ Channel A positive, Z1+ Brown 15 NC NC Blue Shell Shield Shield 4 - - 9-pin D-Sub Connector (male) PIN Option analog (1 VPP) Option digital RS 422 Cable color 1 Sine negative, U1- Channel A negative, Z1- Green 2 0V 0V Brown/Green 3 Cosine negative, U2- Channel B negative, Z2- Pink 4 NC Error , active low Purple 5 Index negative, U0- Index negative, Z0- Black 6 Sine positive, U1+ Channel A positive, Z1+ Brown 7 Power supply, +5V Power supply, +5V White/Green 8 Cosine positive, U2+ Channel B positive, Z2+ Grey 9 Index Positive, U0+ Index positive, Z0+ Red Shell Shield Shield - Strand Wire Option Cable color Analog (1 VPP) Digital RS 422 White/Green Power supply, +5V Power supply, +5V Brown/Green 0V 0V Red Index Positive, U0+ Index positive, Z0+ Black Index negative, U0- Index negative, Z0- Brown Sine positive, U1+ Channel A positive, Z1+ Green Sine negative, U1- Channel A negative, Z1- Grey Cosine positive, U2+ Channel B positive, Z2+ Pink Cosine negative, U2- Channel B negative, Z2- Purple NC Error, active low Yellow NC Error, active high White NC NC Blue NC NC 5 Absolute Maximum Ratings Storage temperature, TS -20 C to + 70 C Operating temperature, TA 0 C to + 55 C Supply voltage, VCC 4.5 V to 5.5V Digital output voltage, VO -0.3V to Vcc +0.3V Recommended Operating Conditions Storage temperature, TS -20 C to + 70 C Operating temperature, TA 0 C to + 55 C Supply voltage, VCC 5 V 10 % Analog output voltage, VO 1 V 0.2V at 120 load Digital output voltage, VO 5 V 10 % (RS422 compatible) Output current per channel, I OUT 15 mA, short circuit proof (analog) 40 mA, short circuit proof (digital) Mechanical Data Cross section (scanning head) 31.5 x 20.2 mm (height x width) Mass (scanning head without cable) 15 g Mass (overall system) Mass of scanning head + 38 g/m Maximum speed (0.5 m resolution) 3.0 m/s (1.0 m resolution) 8.0 m/s (5.0 and 10 m resolutions) 16.0 m/s (1Vpp analog output) 16.0 m/s Measuring scale material Precision float glass Thermal expansion coefficient (Glass scale) 7.8 x 10-6 K-1 (Scale with profile) 13.1 x 10-6 K-1 Extrusion profile material Tempered precision Aluminum, anodized Light source Ultra collimated LED Detector 22-element photodetectors array Electrical Data Maximum analog signal frequency (-3 dB) 400 kHz Maximum power consumption with load (digital output) 200 mA (analog output) 100 mA 6 Output Characteristics Analog Output Signals (Sine U1, Cosine U2 and Index U0) U1 0 SA SU SL 1 2 U2 CU CA 0 CL RF RB U0 RA 0 0 135 360 Signal period 360e Figure 1. Output waveforms for analog output signals. Shown signals are measured in difference mode Analog Signals Sine U1, Cosine U2 Peak-peak amplitude (SA, CA) 1.0 0.2 V Offset |SU-SL|/(2*SA) or |CU-CL|/(2*CA) 0.05 Ratio SA /CA 1.0 0.1 Phase |1+2|/2 90 10 e Index Channel U0 Signal amplitude RA 1.0 +1.6 V -0.6 Index signal zero-crossover width RB, RF 180 90e 7 Digital Output Signal for Options N & P (Ch. A, Ch. B and Index) One cycle Z 1+ A 0 : Phase-shift Z 2+ B 0 Z 0+ Index 0 RL 0 360 Figure 2. Digital output signals, with a quadrature phase-shift between Ch. A and Ch. B. The index pulse, which is active for 90 e, is gated with the incremental signals. Digital Incremental Signals, RS422 compatible Channel A & B Phase-shift 90 e Rise/Fall time 40 ns Index Channel Index pulse width, RL 90 e Rise/Fall time 40 ns 8 Interpolated Digital Output Signal (Ch. A, Ch. B, Index and Error) 0 360e One cycle of square wave signal Z 1+ A 0 One count (90 e) Z 2+ B 0 Z 0+ Index 0 RL Error 0 Analog Signal Period m distance. Figure 3. Interpolated digital output signals (A, B, and Index) and the error signal. The analog signal period corresponds to a 40- Digital Incremental Signals, RS422 compatible Channel A & B Phase-shift 90 e Rise/Fall time 40 ns Index Channel Index pulse width, RL 90 e Rise/Fall time 40 ns Error Channel Error Active high Error Active Low Note: Error signal is non-active for normal operation while an activated Error signal indicates that a fault is detected. Typical cause is due to power failure, loss of encoder light source or encoder signals are out of the limit. 9 Mechanical and Environmental Test The encoders are tested according to the following international standards to ensure that they can withstand the most stringent environmental requirements. Test Name Reference Conditions Vibration (non-operating) DIN IEC 68-2-6 50 Hz - 2 kHz, 10g/15g/30g, 10 cycles in 3 axes 50 Hz - 2 kHz, 30g, 1 cycle (Glass scale only) Shock (non-operating) DIN IEC 68-2-27 10 g, 6 ms, 2000 shocks in 6 directions 20 g, 11 ms, 1000 shocks in 6 directions 50 g, 3 ms, 500 shocks in 6 directions Electromagnetic Compatibility (EMC) DIN EN61000-6-2 Industrial Environment Immunity Test DIN EN61000-4-2 Electrostatic Discharge (ESD): Discharge in air ( 8 kV) and contact discharge ( 4 kV) DIN EN61000-4-3 Electromagnetic RF-field in the range of 80 MHz to 1000 MHz, 80 % AM, 1 kHz DIN EN61000-4-4 Fast transient (bursts, 1 kV) DIN EN61000-4-6 RF-coupling into power line in the range of 0.15 to 80 MHz, 80 % AM, 1 kHz Allowable Mounting and Machine Tool Tolerances With reference to Figure 4, the total tolerances for the linear encoder are given as: Error Description Tolerance y Total tolerance in the y-axis 70 m z Total tolerance in the z-axis 50 m X Roll angle, rotation about the x-axis 50 ' Y Pitch angle, rotation about the y-axis 50 ' Z Yaw angle, rotation about the z-axis 25 ' Y Z X Z X Y Figure 4. Definition of axes and rotational angles for the total allowable tolerance of the linear encoder 10 Recommended circuit Digital RS422 interpolated output signals +5V Z1+ Z1+ 120 Z1- Z1Cable Line Receiver (AM26LS32, DS26LS32) Encoder/Line driver Figure 5. Recommended receiver circuits for the line driver digital output. The same circuit is applicable for Ch. A, Ch. B, Index, and Error channels. Analog 1 VPP Voltage signals - +Ub 120 U + -Ub Cable 0V Encoder Customer circuit Figure 6. Recommended customer receiver circuit for analog output sine, cosine, and index signals. 11 Cable Characteristics Diameter 4 mm Cable structure Twisted pairs with common shield Number of cable cores 12 (1 pair of AWG 28 for power supply, and 5 pairs of AWG 30 for signal lines) The cable complies with UL standard 20963. Operating conditions for the cable depend on the cable diameter and the cable configuration. The operating conditions are given in the following table: Permissible bending radius, R Fixed installation Fixed installation Frequent flexing R 12 mm (0.48 in.) R 40 mm (1.6 in.) Flexible movement R R R R R R Figure 7. Cable bending radius for fixed and flexible installations 12 Ordering Information AEDL Measurement Length (mm) 0220 220 0270 270 0320 320 0370 370 0420 420 0470 470 0520 520 0620 620 0720 720 0770 770 0820 820 0920 920 1020 1020 1240 1240 1440 1440 1640 1640 1840 1840 2040 2040 2200 2200 Custom-Contact Distributor Output Options and Resolution (m) A B C D E F G H L M N P Q S Accuracy per meter (m) Digital 0.05 3* Digital 0.05 5* Digital 0.1 3* Digital 0.1 5* Digital 0.5 3 Digital 0.5 5 Digital 1 3 Digital 1 5 Digital 5 3 Digital 5 5 Digital 10 3 Digital 10 5 3 Analog (40m pitch) Analog (40m pitch) 5 Note: Options with * are not available yet 13 0 1 Color Silver Black Limit Switch (Not yet available), Index Mark A B C D 0 1 2 3 4 5 6 7 A B C D With switch, Every 50mm * With switch, Distance Coded * Without switch, Every 50mm Without switch, Distance Coded * Cable Length (m/Inch), Cable Exit 0.5/19.7, left 0.5/19.7, right 1.0/39.4, left 1.0/39.4, right 2.0/78.8, left 2.0/78.8, right 3.0/118.2, left 3.0/118.2, right Connector Plain cable, stranded wires 9-pin D-Sub male 15-pin D-Sub male 12-pin round www.agilent.com/ semiconductors For product information and a complete list of distributors, please go to our web site. For technical assistance call: Americas/Canada: +1 (800) 235-0312 or (408) 654-8675 Europe: +49 (0) 6441 92460 China: 10800 650 0017 Hong Kong: (+65) 6756 2394 India, Australia, New Zealand: (+65) 6755 1939 Japan: (+81 3) 3335-8152(Domestic/International), or 0120-61-1280(Domestic Only) Korea: (+65) 6755 1989 Singapore, Malaysia, Vietnam, Thailand, Philippines, Indonesia: (+65) 6755 2044 Taiwan: (+65) 6755 1843 Data subject to change. Copyright (c) 2005 Agilent Technologies, Inc. March 3, 2005 5989-2553EN