ing e nuity@ w o rk - Gurley Precision Instruments
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1. Complementary signals omitted for clarity A255 PAGE 3 OF 8 V3 1 Gurley Precision Instruments 514 Fulton Street Troy NY 12180 U S A 800 759 1844 518 272 6300 fax 518 274 0336 Online at www gurley com e mail info gurley com EXTERNAL ELECTRONICS ASSEMBLY ELECTRICAL INSTALLATION We recommend that the 5V supply 300 mA max excluding atypical data bus termination requirements for the encoder be provided from a linear regulated power supply located within 20 feet of the installation Dual supply and return pins are provided to facilitate remote sensing an option provided on most commercially available linear supplies A cleanly regulated switch mode power supply may be adequate in some cases If the encoder is operated from the same supply as the customer s digital interfacing logic an LC filter to suppress RFI on the instrument branch of the supply may be desirable Where possible terminate the instrument shield Pin 13 and the D Sub connector shell at circuit ground potential as close as possible to the ground terminal of the power supply The cover is effective primarily against electric field interference In cases where intense magnetic field disturbances are expected attention to cable routing and additional magnetic shielding may be wise precautions These recommendations should be sufficient to assure reliable operation However optical encoder installations are known for their mechanical a2. MAX 25mA lour Cour 20pF SERIAL OUTPUT Position data is obtained from the encoder by issuing an active low pulse to the negative edge sensitive interrogate input while the clock input is held high this initiates a rotary to digital R D conversion R D conversion proceeds independently of any other signal edge or state and valid data is available at the output serial register after 900 ns Data remains valid until power is removed or a new interrogate pulse is issued Avalid R D conversion is not automatically initiated on power up Typically 30 50 ms should be allowed on power up before interrogation to permit power supplies to settle Serial output is buffered by RS422 differential line drivers andis formatted MSB first LSB last followed by a parity bit The user can select whether parity is odd or even by means of a jumper in the electronics package Clock line must be held high until T Interrogation is triggered by falling edge of INT New data bits become valid about 75 ns after rising clock edge READ wave form is shown for reference RS422 receivers and drivers are Fairchild mA9637A and mA9638 respectively Receivers are terminated by a series RC network 220 W and 0 01 mF spanning the true and complement Inputs TIMING AND SIGNAL CHARACTERISTICS FOR SERIAL OUTPUT MIN 00 ns 900 ns 100 ns 100 ns
3. fax 518 274 0336 CERTIFIED Online at www gurley com e mail info gurley com SPECIFICATIONS MECHANICAL Maximum weights Steel transducer 48 cable Aluminum Transducer 48 cable External electronics Jacketed cable Moment of inertia Starting torque Running torque Max recommended shaft load Axial Radial Bearings Code disc Max operating speed Max slew speed TEMP Aor T TEMP C 19 oz 540 g 13 oz 370 g 5 oz 140 g 0 118 oz in 132 g m 9 0 x 10 in oz s 63 2 g cm 2 0 in oz 14 0 x 10 N m 1 0 in oz 7 0 x 10 N m 13 Ib 58 N 10 Ib 45 N Sealed ABEC 7 chrome on glass 600 rpm 10 000 rpm ENVIRONMENTAL Operating temperature Commercial Automotive Storage temperature Humidity Altitude Shock 32 F to 158 F 0 C to 70 C 40 F to 185 F 40 C to 85 C 40 F to 194 F 40 C to 90 C 98 rh non condensing 0 50 000 ft 0 15 24 km 50 g 11ms Vibration 15 g 0 2000 Hz Transducer IP40 Electronics p60 ELECTRICAL 5 Vdc 0 25 Vdc 300 mA max excluding output buffer requirements Light emitting diodes screened and rated for 100 00 hr life 2 131 072 unique words per shaft revolution other resolutions available see Ordering Info Each data transition is within 15 arcsec of its true position regardless of resolution The error distribution is such that each output code state is always present and in the correct order
4. rents i DIA 1 23 2 500 Wee feel l 31 2 63 50 G BASE CODE A M 1 DA DIA LE i a JI e 10 2 5 PILOT 6 32 X 20 5 1 MIN THD DEPTH La 1 25 1 00 3 HOLES EQUALLY SPACED SHIELDED RBEON CAPI 81 8 25 4 ESP 48 1 2m LONG STANDARD 900 7 6mm MAX e 25 6 4 L 1 2500 1 2495 31 750 31 737 10 2 5 PILOT PILOT DIA ELECTRONICS ASSEMBLY _f KR 221 5 61 DIA THRU 4 HOLES VIN Se BASE CODE C 5 KH ES 4 21 ae 106 9 ZE 2 064 52 43 MAX ZS TP 2 55 64 8 JL 093 2 36 SAARE 3017 6 l J i 0000 1 23 2 4995 n DB 25P ma Leuna G BASE CODE E H DIA PILOT SR ie 890 t DIA 66 68 122 61 E as MAX r H 171 9 10 2 5 PILOT MAX La 97 el e185 24 6 147 0 MAX MAX 170 14 82 THRU 050 1 27 O ch r E L i fi J 3 500 3 84 88 90 97 5 Q i l y l i S Me D 75 be AX06626 AX06627 119 1 SINGLE BRACKET DOUBLE BRACKET ALL DIMENSIONS ARE IN INCHES MM Gurley Precision Instruments 514 Fulton Street Troy NY 12180 U S A PAGE 5 OF 8 800 759 1844 518 272 6300 fax 518 274 0336 Online at www gurley com e mail info gurley com MoDEL ASC3N ABSOLUTE SERIAL NTERFACE GARD The ASC3N greatly simplifies communications between your computer andA25S so you can use an absolute encoder for a wide variety of motion measurement or control applications It provides all the necessary signals
5. Each ASC3N interface board comes with a comprehensive User s Manual and a 3 5 diskette containing test and utility software and example programs for both DOS and Windows GENERAL Hardware compatibility IBM AT compatible or higher computer with an available 16 bit ISA bus expansion card slot 200 3F0 hex occupies 16 contiguous hex addresses user selectable IRQ 5 7 9 10 11 15 NONE user selectable 14 15 16 and 17 bits user selectable I O base address Interrupt request level Data size Parity Axes Supported Connector Interface Serial input from encoder Serial output Maximum data clock rate Minimum data clock rate Maximum data update rate Mating encoder ELECTRICAL Typ Power requirements ENVIRONMENTAL Operating temperature Operating humidity Storage temperature Storage humidity PHYSICAL Size Even or odd user selectable One two or three axes 3 female 15 pin high density D subminiature connectors DE 15S EIA RS 422 differential line receivers Encoder data MSB first parity last EIA RS 422 differential line drivers interrogate pulse and clock signal 3 6 Mhz 28 kHz 100 000 reads per second Model A25S absolute rotary encoder with serial output 5 Vdc 500 mA max w o encoders 0 C to 70 C 32 F to 158 F 0 to 90 non condensing 20 C to 70 C 4 F to 158 F 0 to 95 non condensing Standard length IBM PC Card Gurley
6. S Serial RS 422 diff line driver P Parallel tri state TTL CABLE Cable length in inches 048 Standard 006 Minimum 300 Maximum BASE A Combination Synchro face mount 1 25 pilot dia Cc Square flange mount E Synchro mount 2 5 pilot dia SHAFT 06E 3 8 dia SPECIAL CAPABILITIES FORMAT CABLE BASE SHAFT PKG TEMP SF PKG Electronics package 0 PC board assembly only 1 With enclosure TEMP Operating temperature range C Commercial 0 to 70 C A Automotive 40 to 85 C T Transducer only 40 to 85 C SF Special feature Issued at time of order to cover special customer requirements N No special features ACCESSORIES order separately M04 Mating connector for DB 25P ASC3N IBM PC serial interface card see page 6 CAMxxx Cable A25S elect to ASC3N xxx length inches Max Length 600 SCAO6Exxx Shaft coupling see page 7 AX06399 Synchro cleat kit to mount transducer AX06626 Bracket for one electronics box AX06627 Bracket for two electronics boxes For special situations we can optimize catalog encoders to provide higher frequency response greater accuracy wider temperature range reduced torque non standard line counts or other modified parameters In addition we regularly design and manufacture custom encoders for user specific requirements These range from high volume low cost limited performance commercial applications to encoders for military aerospace and similar high performa
7. assures long life in a variety of industrial applications A proprietary electronic circuit permits the use of a lower resolution code disc this minimizes sensitivity to opto mechanical adjustments and thus maximizes long term mechanical stability REMOTE ELECTRONICS The separate electronics is housed in a compact 4 2 x 2 8 x 0 9 enclosure that can be located up to 25 ft from the transducer standard cable length is 4 ft APPLICATIONS The encoder is designed so that it may be connected directly to the data bus of a microprocessor or microcomputer It offers the advantages of high accuracy simplified hardware and software interfacing robust opto mechanical design wide operating temperature range and very fast response time The Model A25S is ideal for any motion control application requiring an absolute encoder with high resolution accuracy and reliability in a compact configuration Typical applications include robotics precision servo controls radar pedestals and similar AZ EL mounts rotary tables and machine tools Gurley Precision Instruments 514 Fulton Street Troy NY 12180 U S A 800 759 1844 518 272 6300 fax 518 274 0336 Online at www gurley com e mail info gurley com SPECIFICATIONS PARALLEL OUTPUT Position data is obtained from the encoder by issuing an active low interrogate pulse which initiates a rotary to digital R D conversion The interrogate pin is a negative edge sensitive Schmitt trigg
8. other common mode effects e Interpolation is accomplished with proprietary high speed phase angle conversion circuitry which produces true position data very quickly and very accurately The circuitry has been designed for reliable and predictable performance over the rated temperature environment e Because output data is made available only when the user provides an interrogate pulse there is no possibility of chatter in the vicinity of a data transition and hence no need for hysteresis in the circuitry This unique zero hysteresis feature assures error free operation in bi directional applications ABSOLUTE POSITION ENCODING The Model A25S is a high performance absolute optical encoder designed for resolution in the 2 2 range Its position information is stored in a non volatile fashion in the multi track absolute code pattern on the disc If power is lost and re applied absolute position data is immediately available without homing the encoder or counting pulses as is typically required with an incremental device It is especially well suited for applications requiring the highest possible data integrity where electrical noise safety or high performance are important system considerations ROBUST MECHANICAL DESIGN The A25S consists of a low profile transducer module and separate electronics package a configuration that allows it to be used where conventional designs will not fit The rugged 3 8 dia shaft bearing assembly
9. to interrogate and read in the data from up to 3 encoders simultaneously The ASC3N andA25S transmit and receive data serially by RS 422 line drivers and receivers The A25S requires an active low interrogate pulse to initiate a rotary to digital conversion The ASC3N generates this signal and sends it on a separate line simultaneously to each of the three encoders When each encoder has converted rotary position into digital data the ASC3N starts reading and shifting the serial data into its on board shift registers The shift read clock is generated for all three channels in unison You can control the data transmission rate to the ASC3N with convenient on board jumpers Parameters such the quality and length of the transmission line and application timing requirements will affect the maximum baud rate allowable The baud rate can be from 28 kHz to 3 6 MHz which correspond to maximum data update rates from 1 000 to 100 000 encoder reads per second You can also configure the data size from 14 to 17 bits and parity even or odd by jumpers When you are using more than one encoder the data size and parity must be the same for all The ASC3N checks the parity of the incoming data and reports any errors to the status register which also has a busy signal bit that you can poll Alternatively you can assign an IRQ line and ignore the status register if desired A simple I O read from the computer will input the data from the ASC3N to your CPU
10. Natural binary consult factory for other codes Parallel or serial User selectable factory default cw User selectable factory default odd TTL compatible tri state buffered registers Byte wide or word wide user selectable format Schmitt trigger input for interrogate pulse TTL compatible output enable line s 1 MHz Synchronous output with EIA RS 422 differential line drivers MSB first parity last EIA RS 422 differential line receivers for interrogate pulse and clock input 100 kHz 3 6 Mbaud Input power Illumination Max resolution Accuracy Output code Output format Direction of increasing count Parity Parallel Output Input device Max data update rate Serial output Input device Max data update rate NOTE These specifications are applicable under all variations of recommended supply voltage speed temperature and direction of travel Improved performance is available under special conditions please consult factory A255 PAGE 2 OF 8 v3 1 ACHIEVING ACCURACY These design features assure the high accuracy and long term stability of the Model A25S e Multiple reading heads are used in the transducer to eliminate errors caused by disc eccentricity pattern irregularities and non uniform bearing rotation e Back to back photodiodes read the interpolated track in push pull configuration to eliminate errors caused by LED aging temperature changes supply voltage variations and
11. Precision Instruments 514 Fulton Street Troy NY 12180 U S A 800 759 1844 518 272 6300 fax 518 274 0336 Online at www gurley com e mail info gurley com PAGE 6 OF 8 V3 1 A255 MoDEL SCA SHAFT COUPLING OPTIONAL ORDERING INFORMATION SCA 063 USER END B USER END B 04E 1 4 shaft 05E 5 16 shaft 06E 3 8 shaft 06M 6 mm shaft 08M 8 mm shaft 10M 10 mm shaft SPECIFICATIONS Kinematic accuracy with parallel offset 0 1 mm 0 004 in 10 arcsec and angular misalignment 0 09 Torsional rigidity 150 Nem rad 0 1ineoz arcs Maximum parallel offset Maximum axial extension or compression 0 5 mm 0 020 in Maximum angular misalignment a 22 87 29 53 375 10 39 gt 10 39 X om Dii e SOCKETHEAD B SEE NOTE 3 CAP SCREWS SEE NOTE 2 NOTES 1 DIMENSIONS ARE IN MM IN 2 IF B IS IN INCHES SCREWS ARE 4 40 X 5 16 IF B IS IN MM SCREWS ARE M3 X 8 3 TOLERANCE ON USER S SHAFT IS 012 0005 Gurley Precision Instruments 514 Fulton Street Troy NY 12180 U S A PAGE 7 OF 8 800 759 1844 518 272 6300 fax 518 274 0336 v3 1 Online at www gurley com e mail info gurley com we III TITEL CODE RES CODE B Natural Binary RES Resolution words rev 17 2 131 072 16 2 65 536 15 2 32 768 14 2 16 384 FORMAT Data transmission
12. d gt ingenui GURLEY MODEL A255 ABSOLUTE ENCODER MOTION TYPE ROTARY USAGE GRADE INDUSTRIAL OUTPUT ABSOLUTE MAX RESOLUTION J 2 131 072 WORDS COMPACT FAST amp ACCURATE Gurley Precision Instruments Model A25S absolute optical encoder is unique with its advanced design featuring new encoder technology The following features make it far more capable than competitive products e Faster and more accurate than either a resolver based system or any competitive optical encoder e Upto 17 bit resolution the highest available in an encoder designed and priced for industrial applications e A rugged compact transducer 2 5 dia x 1 25 long makes the encoder easier to design into tight spaces e Fully accurate data at 600 rpm permits use at higher shaft speeds e Very high data update rate 1 MHz parallel 100 kHz serial allows the encoder to be used whenever real time data is needed such as velocity feedback applications or wide bandwidth positioning servos e Unique circuitry eliminates hysteresis deadband so there s no error due to bi directional operation e Natural binary bus compatible output permits straightforward hardware and software interfacing e Optional interface card simplifies communication between the encoder and a computer Gurley Precision Instruments Iso 514 Fulton Street 9001 Troy NY 12180 U S A 800 759 1844 518 272 6300
13. er input and may be activated by any digital or analog signal that meets the stated input voltage requirements R D conversion proceeds independently of any other signal edge or state and valid data is available at the output parallel register after 750 ns Data remains valid until power is removed or a new interrogate pulse is issued A valid R D conversion is not automatically initiated on power up Typically 30 50 ms should be allowed on power up before interrogation to permit power supplies to settle Each parallel output line is buffered by a tri state high speed CMOS bus driver compatible with virtually all TTL and CMOS 5 volt logic inputs Two active low output enables chip selects may be used to read high and low bytes separately or they may be tied together for whole word reads With 17 bit resolution data is available as whole word only The parity bit is also tri state and is enabled in conjunction with the high byte The user can select whether parity is odd or even with a jumper in the electronics package Two or more encoders may share a byte wide or word wide output cable provided conventional tri state multiplexing restrictions are observed to avoid bus contention TIMING AND SIGNAL CHARACTERISTICS FOR PARALLEL OUTPUT MIN 100 ns 500 ns CONVERSION IN PROCESS NEW READING 750 ns 1 s HIGH IMPEDANCE 100 ns 250 ns DATA MIN 25 mA
14. for Testing Rotary Accuracy and a printed accuracy plot accompanies each encoder The heart of METRA is an exclusive Gurley designed optical encoder with a resolution of 2 measuring steps rev and NIST traceable absolute accuracy of 1 3 arcsec The certified accuracy is limited by available angle standards not by METRA itself When testing for accuracy the encoder under test EUT is coupled to METRA with precision fixturing As the two encoders are rotated together the position information from METRA is used to interrogate the EUT at 2 097 152 positions around a revolution Thus this test verifies the location of every single output state of the EUT This method reveals all encoder errors and does not depend on statistical assumptions based on an incomplete data set Gurley Precision Instruments 514 Fulton Street Troy NY 12180 U S A 800 759 1844 518 272 6300 fax 518 274 0336 Online at www gurley com e mail info gurley com 10 2 5 098 2 36 1 2500 1 2495 31 750 31 737 IL am 3747 3745 17 6 19 517 9 512 Ge SHAFT DIA 2 370 Gurley Precision 2 52 160 20 8 ae i
15. nce high reliability conditions We would welcome the opportunity to help you with your encoder needs WARRANTY Gurley Precision Instruments offers a limited warranty against defects in material and workmanship for a period of one year from the date of shipment A255 PAGE 8 OF 8 Gurley Precision Instruments 514 Fulton Street Troy NY 12180 U S A 800 759 1844 518 272 6300 fax 518 274 0336 v3 1 Online at www gurley com e mail info gurley com
16. nd electrical variety Gurley will gladly render applications assistance for difficult installations OUTPUT PINOUTS SHIELDED MALE 25 PIN D SUBMINIATURE CONNECTOR PIN 14 BIT 15 BIT 16 BIT 17 BIT SERIAL WIN Sp NIO CO 10 11 12 13 CASE CASE CASE CASE CASE 14 D13 D14 D15 D16 NC 15 D12 D13 D14 D15 NC 16 D11 D12 D13 D14 NC 17 D10 D11 D12 D13 NC 18 D9 D10 D11 D12 NC 19 D8 D9 D10 D11 NC D8 D9 D10 DATA 21 D7 D8 D9 DATA 22 OEH OEH OEH OE CLK 23 PAR PAR PAR PAR CLK 24 GND GND GND GND GND 25 GND GND GND GND GND PAGE 4 OF 8 v3 1 A255 SETTING THE DIP SWITCHES Open the electronics assembly by removing the 4 Philips head screws and lifting off the top cover the one with the label The dip switches can be set as follows this information is also printed on the pc board Count increases Parity is even with CCW shaft rotation Count increases Parity is odd with cw shaft SETTING THE DIP SWITCHES It may be desirable to unplug the electronics to snake the cable through a tight spot First open the electronics assembly by removing the 4 Philips head screws and lifting off the top cover the one with the label Carefully unplug the ribbon cable and the separate shield connector from the electronics board When re mating the transducer to the electronics make sure that they have the same serialnumber A mismatch of these components will result in gross position error
17. s and void the warranty MOUNTING THE ELECTRONICS The simplest way to mount the electronics is with bracket AX06626 for a single box or bracket AX06627 to mount a pair of boxes as in an azimuth elevation or other two axis systems Another choice is to bolt the box directly to a mounting surface First open the electronics assembly by removing the 4 Philips head screws and lifting off the top cover the one with the label Unscrew 4 hex stand offs and lift out the electronics board and the cable you don t have to unplug the cable from the pc board Drill two clearance holes in diagonally opposite corners of the bottom of the lower cover There s plenty of room under the pc board for screw heads After the lower cover is bolted in place carefully reassemble the package by reversing the previous three steps Or if your enclosure provides adequate mechanical and EMI protection you can use the board without the box order PKG code 0 You can mount the board on stand offs but be sure to provide adequate strain relief for the ribbon cable from the transducer PERFORMANCE CERTIFICATION Before shipment Gurley tests all absolute encoders for monotonicity which guarantees that all output code states are present and in the correct order and for accuracy which verifies that the digital output matches the shaft angle input within the stated tolerance These tests are performed on our exclusive METRA test system Master Encoder
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