HEDB-9100 and HEDB-9000 Two Channel Optical Incremental Encoder Modules Bundle With Codewheel Data Sheet Description Features The HEDB-9100 and HEDB-9000 series are two channel High Performance optical incremental encoder modules off ered with a Resolution from 96 CPR Up To 1000 CPR (Counts Per codewheel. When used with a codewheel, these low cost Revolution) modules detect rotary position. Each module consists of Low Cost a lensed LED source and a detector IC enclosed in a small C-shaped plastic package. Due to a highly collimated light Easy to Mount source and a unique photodetector array, these modules No Signal Adjustment required are extremely tolerant to mounting misalignment. Small Size The HEDB-9100 and 9000 has two channel quadrature Operating Temperature: -40C to 100C outputs. TTL Compatible The HEDB-9100 is designed for use with a HEDS-5120 Two Channel Quadrature Output codewheel which has an optical radius of 11.00 mm (0.433 inch).The HEDB-9000 is designed for use with a Single 5V Supply HEDS-6100 codewheel which has an optical radius of Applications 23.36 mm (0.920 inch). The HEDB-9100 and 9000 provide sophisticated motion The quadrature signals and the single 5V supply input are control detection at a low cost, making them ideal for high accessed through fi ve 0.025 inch square pins located on volume applications. Typical applications include printers, 0.1 inch (pitch) centers. plotters, tape drives, and industrial and factory automa- tion equipment. Note: Avago Technologies encoders are not recommended for use in safety critical applications. Eg. ABS braking systems, power steering, life support systems and critical care medical equipment. Please contact sales representative if more clarifi cation is needed.Theory of Operation The HEDB-9100 and 9000 is emitter/detector modules. Cycle Error (C): An indication of cycle uniformity. The diff er- Coupled with a codewheel, these modules translate ence between an observed shaft angle which gives rise to the rotary motion of a shaft into a two-channel digital one electrical cycle, and the nominal angular increment of output. 1/N of a revolution. As seen in Figure 1, the modules contain a single Light Pulse Width (P): The number of electrical degrees that an Emitting Diode (LED) as its light source. The light is col- output is high during 1 cycle. This value is nominally 180e limated into a parallel beam by means of a single poly- or 1/2 cycle. carbonate lens located directly over the LED. Opposite the Pulse Width Error (P): The deviation, in electrical degrees, of emitter is the integrated detector circuit. This IC consists the pulse width from its ideal value of 180e. of multiple sets of photodetectors and the signal process- ing circuitry necessary to produce the digital waveforms. State Width (S): The number of electrical degrees between a transition in the output of channel A and the neighboring The codewheel rotates between the emitter and detector, transition in the output of channel B. There are 4 states per causing the light beam to be interrupted by the pattern of cycle, each nominally 90e. spaces and bars on the codewheel. Phase ( ): The number of electrical degrees between the The photodiodes which detect these interruptions are center of the high state of channel A and the center of the arranged in a pattern that corresponds to the radius and high state of channel B. This value is nominally 90e for design of the code-wheel. These detectors are also spaced quadrature output. such that a light period on one pair of detectors corre- sponds to a dark period on the adjacent pair of detectors. Phase Error (): The deviation of the phase from its ideal value of 90e. The photodiode outputs are then fed through the signal processing circuitry resulting in A, Abar, B, Bbar. Two com- Direction of Rotation: When the codewheel rotates in the parators receive these signals and produce the fi nal outputs clockwise direction viewing from top of the module for channels A and B. Due to this integrated phasing (direction from V to G), channel A will lead channel B. If technique, the digital output of channel A is in quadrature the codewheel rotates in the opposite direction, channel with that of channel B (90 degrees out of phase). B will lead channel A. Optical Radius (Rop): The distance from the codewheels Defi nitions center of rotation to the optical center (O.C) of the encoder Note: Refer to Figure 2 module. Count (N): The number of bar and window pairs or counts Specifi cation per revolution (CPR) of the codewheel. For encoder electrical, mechanical specifi cations, One Cycle (C): 360 electrical degrees (e), 1 bar and window codewheel technical specifi cations and additional infor- pair. mations pls refer to : One Shaft Rotation: 360 mechanical degrees, N cycles. HEDS-9000 /9100 Datasheet. Position Error (): The normalized angular diff erence HEDS/HEDG/HEDM 51xx/61xx Codewheel Datasheet between the actual shaft position and the position indicated by the encoder cycle count. 2