linear optical incremental encoder modules technical data heds-9200 series features ? high performance ? high resolution ? low cost ? easy to mount ? no signal adjustment required ? insensitive to mechanical disturbances ? small size ? -40 c to 100 c operating temperature ? two channel quadrature output ? ttl compatible ? single 5 v supply description the heds-9200 series is a high performance, low cost, optical incremental encoder module. when operated in conjunction with a codestrip, this module detects linear position. the module consists of a lensed led source and a detector ic enclosed in a small c-shaped plastic pack- age. due to a highly collimated light source and a unique photodetector array, the module is extremely tolerant to mounting misalignment. the two channel digital outputs and the single 5 v supply input are accessed through four 0.025 inch square pins located on 0.1 inch centers. five standard resolutions between 4.72 counts per mm (120 counts esd warning: normal handling precautions should be taken to avoid static discharge. package dimensions note: codestrip not included with heds-9200 26.67 (1.05) heds-9200 15.2
(0.60) c l 17.27
(0.680) 20.96
(0.825) 1.85 (0.073) 8.64 (0.340)
ref. aligning recess
2.44/2.41 dia.
(0.096/0.095)
2.16 (0.085)
deep 1.02 ?0.10
(0.040 ?0.004) 5.1 (0.20) x00 yyxx option code 0.63 (0.025)
sqr. typ. 2.54 (0.100) typ. date code 1.0 (0.04) 3.73 ?0.05
(0.147 ?0.002) 2.67 (0.105) dia.
mounting thru
hole 2 places 2.44/2.41 x 2.79
(0.096/0.095 x 0.110)
2.16 (0.085) deep optical center 1.52 (0.060) 20.8
(0.82) 11.7
(0.46) 8.6 (0.34) 1.78 ?0.10
(0.070 ?0.004) 2.92 ?0.10
(0.115 ?0.004) 10.2
(0.400) 5.46 ?0.10
(0.215 ?0.004) optical
center line 2.54
(0.100) 2.21
(0.087) 5.8
(0.23) 6.35 (0.250) ref. aligning recess
2.44/2.41 x 2.79
(0.096/0.095 x 0.110)
2.16 (0.085) deep 4.11 (0.162) aligning recess
2.44/2.41 dia.
(0.096/0.095)
2.16 (0.085) deep optical
center 45 8.81
(0.347) 11.9
(0.47) 4.75 ?0.10
(0.187 ?0.004) 2.9
(0.11) 1.8
(0.07) 6.9 (0.27) v cc gnd 5 ch. b 4 v cc 3 ch. a 2 n.c. 1 gnd side a side b typical dimensions in
millimeters and (inches)
2 per inch) and 7.87 counts per mm (200 counts per inch) are available. consult local agilent sales representatives for other resolutions ranging from 1.5 to 7.87 counts per mm (40 to 200 counts per inch). applications the heds-9200 provides sophisticated motion detection at a low cost, making it ideal for high volume applications. typical applications include printers, plotters, tape drives, and factory automation equipment. theory of operation the heds-9200 is a c-shaped emitter/detector module. coupled with a codestrip it translates linear motion into a two-channel digital output. as seen in the block diagram, the module contains a single light emitting diode (led) as its light source. the light is collimated into a parallel beam by means of a single polycarbonate lens located directly over the led. opposite the emitter is the integrated detector circuit. this ic consists of multiple sets of photodetectors and the signal processing circuitry necessary to produce the digital waveforms. the codestrip moves between the emitter and detector, causing the light beam to be interrupted by the pattern of spaces and bars on the codestrip. the photodiodes which detect these interruptions are arranged in a pattern that corresponds to the count density of the codestrip. these detectors are also spaced such that a light period on one pair of detectors corresponds to a dark period on the adjacent pair of detectors. the photodiode outputs are then fed through the signal processing circuitry resulting in a, a, b and b. two comparators receive these signals and produce the final outputs for channels a and b. due to this integrated phasing tech- nique, the digital output of channel a is in quadrature with that of channel b (90 degrees out of phase) . definitions count density (d): the number of bar and window pairs per unit length of the codestrip. pitch: 1/d, the unit length per count. electrical degree ( e): pitch/ 360, the dimension of one bar and window pair divided by 360. 1 cycle (c): 360 electrical degrees, 1 bar and window pair. pulse width (p): the number of electrical degrees that an output is high during 1 cycle. this value is nominally 180 e or 1/2 cycle. pulse width error ( d p): the deviation, in electrical degrees, of the pulse width from its ideal value of 180 e. state width (s): the number of electrical degrees between a transition in the output of channel a and the neighboring transition in the output of channel b. there are 4 states per cycle, each nominally 90 e. block diagram output waveforms
3 state width error ( d s): the deviation, in electrical degrees, of each state width from its ideal value of 90 e. phase ( f ): the number of electrical degrees between the center of the high state of channel a and the center of the high state of channel b. this value is nominally 90 e for quadrature output. phase error ( d f): the deviation of the phase from its ideal value of 90 e. direction of movement: when the codestrip moves, relative to the module, in the direction of the arrow on top of the module, channel a will lead channel b. if the codestrip moves in the opposite direction, channel b will lead channel a. absolute maximum ratings parameter symbol min. typ. max. units notes storage temperature t s -40 100 c operating temperature t a -40 100 c supply voltage v cc -0.5 7 volts output voltage v o -0.6 v cc volts output current per channel i o -10 5 ma recommended operating conditions parameter symbol min. typ. max. units notes temperature t -40 100 c supply voltage v cc 4.5 5.5 volts ripple < 100 m vp-p load capacitance c l 100 pf 3.2 k w pull-up resistor count frequency f 100 khz velocity note: the module performance is guaranteed to 100 khz but can operate at higher frequencies. encoding characteristics encoding characteristics over recommended operating range and recommended mounting tolerances. these characteristics do not include codestrip defects. parameter symbol min. typ. max. units notes pulse width error d p 7 35 elec. deg. logic state width error d s 5 35 elec. deg. phase error df 2 13 elec. deg. ( inch counts sec inch x ) electrical characteristics electrical characteristics over recommended operating range, typical at 25 c parameter symbol min. typ. max. units notes supply current i cc 17 40 ma high level output voltage v oh 2.4 volts i oh = -40 m a max. low level output voltage v ol 0.4 volts i ol = 3.2 ma rise time t r 200 ns c l = 25 pf fall time t f 50 ns note: 1. for improved performance in noisy environments or high speed applications, a 3.3 k w pull-up resistor is recommended. r l = 11 k w pull-up
4 recommended codestrip characteristics codestrip design must take into consideration mounting as referenced to either side a or side b (see figure 4). mounting as referenced to side b mounting as referenced to side a static charge warning: large static charge on codestrip may harm module. prevent accumulation of charge. parameter symbol mounting ref. side a mounting ref. side b units window/bar ratio w w /w b 0.7 min., 1.4 max. 0.7 min., 1.4 max. mounting distance l l a 0.51 (0.020) l b 3 3.23 (0.127) mm (inch) window edge to s 0.90 (0.035) min. 0.90 (0.035) min. mm (inch) module opt center line parallelism a 1.3 max. 1.3 max. deg. module to codestrip note: all parameters and equations must be satisfied over the full length of codestrip travel including maximum codestrip runout. figure 1. codestrip design. mounting thru hole aligning recess l a w b w w 1.0 (0.040) ref. module optical center line s s mounting thru hole aligning recess l b w b w w pitch 4.75 (0.187) ref.
5 mounting considerations notes: 1. these dimensions include codestrip warp. 2. reference definitions of l a and l b on page 4. 3. maximum recommended mounting screw torque is 4 kg-cm (3.5 in-lbs).
connectors manufacturer part number mounting surface amp 103686-4 both 640442-5 side b dupont 65039-032 with 4825x-000 term. both agilent heds-8902 with 4-wire leads side b molex 2695 series with 2759 series term. side b ordering information heds-9200 option resolution pitch counts per mm (inch) mm (inch) per count 100 - 3.937 (100) 0.254 (0.0100) l00 - 4.72 (120) 0.212 (0.0083) m00 - 5.00 (127) 0.200 (0.0079) p00 - 5.91 (150) 0.169 (0.0067) q00 - 7.09 (180) 10.141 (0.0056) r00 - 7.87 (200) 0.127 (0.0050) 300 - 11.81 (300)* 0.085 (0.0033)* 360 - 14.17 (360)* 0.071 (0.0028)* consult local agilent sales representatives for other resolutions. *please refer to separate heds-9000/9100/9200 extended resolution series data sheet for detailed information. 6
www.semiconductor.agilent.com data subject to change. copyright ? 1999 agilent technologies, inc. obsoletes 5963-3863e (12/94) 5965-5888e (11/99)
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