Agilent AEAS-84AD 14/12 Bit Multi-turn Encoder Module Data Sheet

Transcription

1 Agilent AEAS-84AD 4/2 Bit Multi-turn Encoder Module Data Sheet General Description The AEAS-84AD provides all functions as an optoelectronicmechanical unit in order to implement with AEAS-7 an absolute multi-turn encoder with a combine capacity of up to 3 bits. The unit consists of an IR-LED circuit board, a phototransistor (PT) circuit board, and 6 or 7 code wheels arranged in between the PCBs. Specifications The multi-turn unit is available in the following versions: 2-bit solid shaft 4-bit solid shaft Features 6384 (4bits) and 496 (2bits) revolution count versions Optical, absolute multi-turn assembly with max. Ø55 mm and typical height.9 mm. Operating temperatures of -4 C to +85 C Mechanical coupling by means of gearwheels with module of.3 Operating speeds up to 2, rpm A 2x4-pole pin strip for power supply and signals 5V +/-% power supply with low power consumption Code wheel-like multiplexing of the digital position data

2 Pinning SEE Detail Detail Pins allocation:. GND 2. MTDAT2 3. MTDAT 4. MTDAT 5. MTMUX2 6. MTMUX 7. MTMUX 8. VCC 8.2 Side View Bottom View Note: 3 rd angle viewing Example of matching connector: MPE GARRY 52 Series, No. BL2-43GGG-8 Block Diagram and Detailed Description In the following descriptions, the I/O pins are enclosed by a box, e.g., MTMUX[2:]. VCC (+5V) 7x 3 PT's 7x 3 IR's of 8-Decoder 3 MTMUX[2:] 3 x 4K7 3 3 x K 3 3 x 4K7 3 MTDAT[2:] Comparator GND 2

3 Multiplexing and Position Data Each of the :4 reduced 7 code wheels generates a 3-bit code, from which the 4-bit Gray code can be generated as position data through V-bit processing. The 3-bit code is identical electrically for all code wheels, only the projection on the mechanical angle (the revolutions) is different according to the :4 divisions. The code and the data bits and V-bits to be generated are shown in the following diagram for the code wheel : Shaft Turns MSB Singleturn. Wheel Turns. MTDAT[]. MTDAT[]. MTDAT[2] Gray Code (generated) Data-Bit Data-Bit2 V-Bit2 The 3-bit codes of the code wheels to 7 are output on MTDAT[2:] de-multiplexed with MTMUX[2:]. Here, the binary value on MTMUX[2:] corresponds to the code-wheel number ( = code wheel, 2 = code wheel 2, etc.). The configuration is displayed with the value. The following table shows the assignments: Bin/Dec MTMUX[2:] MTDAT[2] MTDAT[] MTDAT[] / / 2 to / 7 3-bit code wheel 3-bit code wheel 2 to 3-bit code wheel 7 / always = 2 bit = 4 bit = MUxSS 3

4 Gray code-generation Logic Diagram For the readout schematic of the multi-turn code gears, i.e. with the user s microcontroller, there must be a logical replication of the V-bit multiplexers. This can be done by a bit manipulation or by look up tables. Care needs to be taken with the real time readout conditions. The procedure is as follows : From MTDAT-Demux (Code-Wheel x) Cx[] S Y 4x MUX2 S Y (V-Bit2) (Data-Bit2). The 3 bits (MTDAT[2:] of each gear (C[2:] bits C7[2:]) are continuously de-multiplexed. Thus there are maximal 3bits x 7gears = 2Bit AEAS-84AD-Data in parallel. Cx[] XOR S Y 2. Synchronous to the readout of the AEAS-7 sensor, those AEAS-84AD bits (depending on the MSB bit (.-bit) of the AEAS- 7) needs to be complemented to the complete Gray code word (cascading). S Y D (Data-Bit) 3. The bit change of the complete Gray code will be synchronized by the AEAS- 7 and thus electronically eliminating gear play. The logic diagram for ONE gear is shown in the following diagram (V-bit-Multiplexer). Note: To simplify the synchronization with AEAS7 (Single turn encoder), the total solution has been embedded into a single chip - MUIC. Please refer to the Ordering Information for this device. Truth Table Cx[] Cx[] D 4

5 The following diagram shows the cascading of the V-bit- Multiplexer of all gears. The outputs are the 4bits Gray code in parallel. The MSB of the complete code is dependant on the total resolution of the system. It can be used in steps of 2 bits (4Bit,2Bit, etc). Unused higher bits should be masked to logical zero. V-Bit-Multiplexer-Cascade C7[2] Demuxed Code-Wheel 7 C7[] C7[] C6[2] Demuxed Code-Wheel 6 C6[] C6[] Cx[] Cx[] Cx[] Cx[] D D Gray-Bit4 Gray-Bit3 (MSB for 4Bit) Gray-Bit2 Gray-Bit2 Gray-Bit (MSB for 2Bit) Gray-Bit With the data-multiplexer IC version of the multi-turn encoder module, the data multiplexer IC will perform the complete driving and data processing of the encoder units while maintaining all time constraints. Demuxed Code-Wheel 5 C5[2] C5[] C5[] Cx[] Cx[] D Gray-Bit9 Gray-Bit8 Demuxed Code-Wheel 2 C2[2] C2[] C2[] Cx[] Cx[] D Gray-Bit3 Gray-Bit2 Demuxed Code-Wheel C[2] C[] C[] Cx[] Cx[] D Gray-Bit Gray-Bit Sample AEAS-7 MSB 5

6 Electrical Specifications Absolute Maximum Ratings Symbol Parameter Limits Units VCC DC Supply Voltage -.3 to +6. V V i Input Voltage -.5 to +5.5 V V o Output Voltage -.5 to +VCC +.5 V %RH Moisture Level (Non-Condensing) 85 % T stg Storage Temperature -4 to + C Note : This device meets the ESD ratings of the IEC6-4-2 HBM Level 4 (8KV) Recommended Operating Conditions Symbol Parameter Values Units VCC DC Supply Voltage +4.5 / +5. / +5.5 V T amb Ambient Temperature -4 to +85 C t DMUXRD Delay Multiplex Read 64 µs S RPM Encoder Shaft r.p.m max 2, /min DC Characteristics VCC = 4.5 to 5.5 V / T amb = -4 to +85 C Values Symbol Parameter Min Typ. Max Units V OH MTDAT[2:] Output High Voltage (K Pull-up) I OH = -5µA 4. V V OL MTDAT[2:] Output Low Voltage (4K7 Series-R) I OL = 5µA.4 V V IH Input High Voltage VCC=4.5V VCC=5.5V V V IL Input Low Voltage.8 V I IL / I IH MTMUX[2:] Input Current., VIN=VCC or V K Pull-down - µa I CC VCC Supply Current 2 ma Timing Characteristics VCC= 4.5 to 5.5V / T amb = -4 to +85 C Values Symbol Parameter Min Typ Max Units t R / t F Input Transition Rise-/Fall-Time.8V / 3.V 5 ns t DMUXRD Delay Multiplex Read 57 µs S RPM Encoder Shaft r.p.m 2K /min MTMUX[2:] old value new value t DMUXRD MTDAT[2:] old value new value 6

7 Application Note The encoder is mechanically fixed by means of holes in adapters, which accommodate M3 threads. The encoder has 2 adapters for attaching in a 3 x 2 and 4 x 9 arrangement (for details see the mechanical drawings in the following page). The mechanical coupling of the encoder shaft is realised by means of gearwheels with a module of.3, 4 teeth. The zero positions of the coupling wheels are locked with a plastic plug for alignment to the AEAS-7, with the coupling wheel being able to compensate for an angle error of about +/-7. The electrical connection is realized by means of a 2x4 pin strip (.27mm pitch), which is plugged into a corresponding female connector. The encoder is attached with a plastic plug that locks the absolute zero position. During the mating of the gearwheel and the encoder coupling wheel it may be necessary to align the teeth of the gears for proper matching. The plastic plug can be removed upon integration with the gearwheel. Plastic plug is removed upon integration with gearwheel Zero position of coupling wheel Plastic plug Gearwheel on the motor shaft, module.3, 4 teeth 7

8 Mechanical Drawing ±. 24.±..9± ±. 35.4±. 24.±. 6.5± (Dimensions are in millimeters)

9 Ordering Information AEAS-84AD-LBSC AEAS-84AD-LBSF multi-turn, solid shaft, serial, 2 bit multi-turn, solid shaft, serial, 4 bit Ordering information for MUIC: MUIC-V leaded, industrial temperature range +85 C MUIC-V-X79 lead-free, industrial temperature range +85 C Note: The manufacturer contact for the above MUIC part numbers is as follows: OPTOLAB Microsystems AG Konrad-Zuse-Str.4 DE-9999 Erfurt / Germany Phone: Fax: agilent@optolab.com semiconductors For product information and a complete list of distributors, please go to our web site. For technical assistance call: Americas/Canada: + (8) or (48) Europe: +49 () China: Hong Kong: (+65) India, Australia, New Zealand: (+65) Japan: (+8 3) (Domestic/International), or (Domestic Only) Korea: (+65) Singapore, Malaysia, Vietnam, Thailand, Philippines, Indonesia: (+65) Taiwan: (+65) Data subject to change. Copyright 24 Agilent Technologies, Inc. October 6, EN