Catalog excerpts
Absolute Optical Shaft EncoderPage 1 of 6 The A2 optical encoder is a 12 bit absolute rotary encoder which reports a shaft angle within a single 360 degree rotation of a shaft. Unlike incremental, sometimes called relative, style encoders the A2 provides true (absolute) shaft position eliminating the need for a home or zero cycle after a supply voltage power cycle. The A2 communicates over a RS 485 style serial bus utilizing US Digital's SEI (Serial Encoder Interface) which allows for simple, quick and convenient networking of multiple SEI devices on a single network. PLCs, motion controllers and computers can also reside on the SEI bus as well by use of US Digital's SEI to USB interface device. For complete information about the SEI bus please refer to the SEI Communications Protocol webpage. The A2 is also available with an optional analog output. The analog output option provides a maximum voltage range of 0 to 4.095 volts with 12 bit resolution. The output voltage can be scaled by simple SEI commands to provide user defined voltage ranges. From the factory the analog output voltage is set to 0 to 3.599 VDC range. Please note that with the A2 analog output option only one device may reside on a SEI bus. ► Sleeve bushing or ball bearing versions ► 12-bit resolution and resolution field programmable from 2 to 4096 codes per revolution (3600 factory default) ► Full 360 degrees range, 7 msec update time ► Low power drain of 18.5 mA max., and 2.5 mA in sleep mode ► Field programmable parameters such as setting zero position point (demo software available for download below) ► EEPROM stores downloadable parameters ► 9600 baud default data rate adjustable up to 115Kbaud ► 12-bit analog voltage output option (0 to +3.599 volts factory default setting. Field programmable up to 0 to +4.095 volts) ► Multi-turn mode (note: power must be maintained to prevent reset to zero) ► -25 to 70 degrees C. operating temperature DIGITAL Vancouver, Washington 98684, USA www.usdigital.com Toll-free: 800.736.0194
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Absolute Optical Shaft Encoder ► www.usdigital.com/support/software/sei ► www.usdigital.com/assets/USDProducts.zip (.zip file with installer) Ball Bearing A2 Absolute Optical Shaft Encoder Ball Bearing Version E-OPTION COVER M-OPTION BASE (REAR SHAFT EXTENSION) (MOUNTING PLATE) DIGITAL Vancouver, Washington 98684, USA UNITS: INCHES [MM] METRIC SHOWN FOR REFERENCE ■ Sleeve Bushing uss= DIGITAL 1400 NE 136th Avenue Vancouver, Washington 98684, USA info@usdigital.com www.usdigital.com Local: 360.260.2468 Toll-free: 800.736.0194 Rev. 171018113253
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A2 Absolute Optical Shaft Encoder Page 3 of 6 Parameter Operating Temperature Vibration (5Hz to 2kHz) Electrostatic Discharge, IEC 61000-4-2 Units C G kV Sleeve Bushing Ball Bearing Typical Shaft Torque 0.5 in-oz (S-option) 0.3 in-oz (N-option) Bearing Life L10 = (90/Ft)3 * Where L10 = bearing life in millions of revs, and Fr = radial shaft loading in pounds Max. Shaft Total Indicated Runout Max. Panel Nut Tightening Torque uss= DIGITAL 1400 NE 136th Avenue Vancouver, Washington 98684, USA info@usdigital.com www.usdigital.com
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DIGITAL Vancouver, Washington 98684, USA www.usdigital.com Toll-free: 800.736.0194
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Absolute Optical Shaft Encoder Page 5 of 6 0 SEI Network 0 Analog Output The analog version of the A2 has a 12-bit DAC on the output which feeds to 2 lines that are otherwise used for the BUSY handshaking pair. This DAC has a full range of 0 to 4.095 Volts which is 1 mV per count. The absolute position value which the internal microcontroller sends to that DAC is the same as the digital value that it sends to the host over SEI. Since the resolution (which represents the number of codes per revolution) is field programmable, the range of the DAC will also follow that setup. The...
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A2 Absolute Optical Shaft Encoder Page 6 of 6 ^ Ordering Information A2 -Interface S =Default - SEI Bus A =Analog Voltage / SEI Bus Torque S =Default - Sleeve bushing with drag B =Ball Bearing N =Sleeve bushing with light static drag Cover D =Default E =Rear shaft extension Base D =Default M =4-hole mounting plate Notes ► Cables and connectors are not included and must be ordered separately. ► US Digital® warrants its products against defects in materials and workmanship for two years. See completewarranty for details. DIGITAL Vancouver, Washington 98684,...
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