Rotary Encoders
Rotary Encoders

Anaheim Automation's immense selection of Encoders provides you with speed and positioning solutions that can't be beat. Our Incremental Rotary Encoders are offered in either optical or magnetic-type read head, and include single-ended, differential, and high-resolution encoder outputs. Anaheim Automation's encoders are available in bore diameters ranging from .059" to 1.73", 2 to 10,000 Cycles Per Revolution (CPR), and are capable of tracking up to 200,000 cycles per second. Additional options inlude a third or fourth index channel, U/V/W Commutation Output, +5-30VDC encoder input voltage range, encoder mounting, Analog, Open-Collector, Push-Pull, and Line Driver Output, and custom cable lengths are just more reasons why our encoder line leaves the competition behind.

  • Single-Ended or Differential Outputs for ABI Channels
  • Low-Cost; Compact Rugged Housing
  • 32 to 5,000 Cycles Per Revolution (CPR)
  • 128 to 20,000 Pulses Per Revolution (PPR)
  • Optional Third and Fouth Index Channel
  • Tracks 0 to 100,000 Cycles Per Second
  • Compatible with .059" to 1.00" Bore Size Diameters
  • Operating Temperature of -40 to +100°C
  • Powered From a Single +5VDC Power Supply
  • 2-Channel Quadrature Squarewave Outputs
  • Allows for ± .010" Axial Shaft Play
  • Tracks 0 to 200,000 Cycles Per Second
  • 100 to 8192 Pulses Per Revolution (PPR)
  • Operating Temperature of -40° to +125°C
  • 2-Channel Quadrature with Gated Index and Optional Commutation
  • (10-12)-Bit PWM Output - (1024 - 4096) Positions Per Revolution, (0.25-2.6)kHz
  • Fits Shaft Diameters from 0.125 to 0.250 (inch)
  • Mounts onto 0.750, 1.280, and 1.812 (inch) Bolt Circles
  • Accepts ±0.025 (inch) Axial Shaft Play
  • Operating Temperature of -40° to +125°C
  • Single-Ended or Differential Outputs for ABI Channels
  • U/V/W Commutation Outputs
    (Differential or Open-Collector)
  • 100 to 2,560 Cycles Per Revolution (CPR)
  • 400 to 10,240 Pulses Per Revolution (PPR)
  • Tracks 0 to 200,000 Cycles Per Second
  • Optional Third and Fourth Index Channel
  • Compatible with .125" to 1.125" Bore Size Diameters
  • Operating Temperature of -40 to +100°C
  • Powered From a Single +5VDC Power Supply
  • 2-Channel Quadrature Squarewave Outputs
  • Allows for ± .005" Axial Shaft Play
  • Optical and Magnetic Type
  • Single-Ended or Differential Outputs for ABI Channels
  • U/V/W Commutation Outputs
    (Differential or Open-Collector)
  • 2 to 10,000 Cycles Per Revolution (CPR)
  • 8 to 40,000 Pulses Per Revolution (PPR)
  • Optional Third and Fourth Index Channel
  • Compatible with .197" to 1.73" Bore Size Diameters
  • Powered From a Single +5VDC, +5-30VDC, or +10-30VDC Power Supply
  • Operating Temperature of -20° to +105° C
  • Allows for ± .005" Axial Shaft Play
  • Programmable Incremental Encoder
  • Resolution from 1 to 65536 PPR
  • IP 65 Rating
  • Push-Pull and Line Driver compatible output
  • Selectable Index length 90 or 180° el.
  • Voltage 5 VDC or 10-30 VDC
  • Programmable via USB cable
Rotary Encoders

Frequently Asked Questions
What are the advantages of Magnetic Rotary Encoders over Optical Rotary Encoders?
Some of the advantages of Magnetic Rotary Encoders over Optical Rotary Encoders are the following:

1. Are not susceptible to various contaminants such as dirt, dust and moisture
2. Not vulnerable to light exposure
3. Greater reliability and durability

How do you install Rotary Encoders?
For step by step tutorials on how to install Anaheim Automation’s Optical Rotary Encoders to your mounting surface, please visit:

Does any encoder disk (codewheel) work with any encoder module?
No. Rotary Encoders have modules specifically designed to work a particular encoder disk resolution and disk diameter. Swapping encoder modules not designed for the specific encoder disk may result in inaccuracies in the output signals of the encoder channels.

What is PPR for Rotary Encoders?
PPR stands for Pulses per shaft Revolution. It is the amount of pulses produced with one encoder revolution. For linear motion, PPR is measured to be pulses per inch or millimeter. This term should not be confused with CPR (Cycles per Revolution) which is the number of lines on an optical encoder disk.

Example: Rotary Encoders with a disk resolution of a 1000 CPR can provide a resolution of up to 4000 pulses per shaft revolution. This being the resultant of quadrature decode (4X decode) which is a common practice to count all the transitions of a squarewave.

When is an optical encoder superior to a magnetic encoder?
Generally, Optical Rotary Encoders can produce more pulses per revolution (PPR). For PPR values above 2048, optical encoders may be the only choice. In the past, optical encoders were more accurate than some magnetic encoders, even at the same PPR.

Can I order stepper motors with encoders added? How do I go about it?
Yes. Encoders can not only be added to stepper motors, but brushless motors as well. Please refer to our Encoders located under Accessories on our web site. Anaheim Automation offers a line of single-ended or differential incremental rotary encoders. These encoders are available in sizes to cover NEMA 08 to 42 motors. These encoders have the capability to track from 0 to 100,000 cycles per second, with options of 32 to 2,500 cycles per revolution, with or without index features. Encoders are configured as motor adders, for dual shaft motors, or can be purchased separately, located on our Encoder web pages. Encoder cables are available, but also purchased separately.

Do I need to purchase a Centering Tool for my Rotary Encoder?
Anaheim Automation's reusable centering tools can be used to simplify the encoder installation process. Each centering tool is designed specifically to fit Anaheim Automation Rotary Encoders, aligning the base relative to the shaft, ensuring absolute accuracy. Although a centering tool is not required for installation, they are recommended when mounting using screws that are smaller than 4-40, or when position of the mounting holes is in question.

Who is the mating connector manufacturer of the ENC-EC35 Rotary Encoders?
The mating connector manufacturer for the ENC-EC35 cable connector is JAE. Please refer to the below part numbers for customers seeking to make their own cables for these types of rotary encoders.

Shell Part Number: JAE# FI-W15S
Pins Part Number: JAE# FI-C3-A1-15000.

What is the difference between an Optical Encoder and a Commutation Encoder?
An optical commutation encoder is a variation of traditional optical rotary encoders. The commutation encoder consists of the same electronics but with a series of commutated tracks on the outer edge of the encoder disk. The benefits of commutation encoders are evident in applications that require position and/or speed control. Commutation encoders can help eliminate shifting errors by aligning the U/V/W commutation output of the encoder to the output phases of the motor which allows for an increase in precision performance.

What is a magnetic encoder?
Magnetic Rotary Encoders is a sensor of mechanical motion that generates digital squarewave or analog signals in response to motion. As an electro-mechanical device, an encoder is able to provide motion control system users with information concerning position, direction, velocity and acceleration.

How do I determine the linear distance traveled of my encoder?
To obtain the linear distance traveled for linear encoders, it is important to determine the number of counts per inch which then can be used to determine the number of full squarewave pulses per inch. You can use the formula for Rotary Encoders to determine this value. Refer to the example below:

Counts per Inch = (1/Resolution)*(1/1000)*25.4
Full Squarewave Pulses per Inch = (Counts per Inch) / 4

Example: Resolution = 5 microns
Counts per Inch = 1/(5*10^-6)*(1/1000)*25.4 = 5080
Full Squarewave Pulses per Inch = 5080/4 = 1270

What is an Encoder?
An encoder is a sensor of mechanical motion that generates digital signals in response to motion. As an electro-mechanical device, an encoder is able to provide motion control system users with information concerning position, velocity and direction. There are two different types of encoders: linear and rotary. A linear encoder responds to motion along a path, while rotary encoders respond to rotational motion. An encoder is generally categorized by the means of its output. An incremental encoder generates a train of pulses which can be used to determine position and speed. An absolute encoder generates unique bit configurations to track positions directly.

Helpful Information
Along with the rotary encoders, Anaheim Automation carries a comprehensive line of single-ended and differential encoder cables with four, six, and eight leads, cable lengths up to 16 feet, and encoder centering tools. Additionally, Anaheim Automation offers an extended line of stepper, brushless and servomotors which can implement encoders for your application needs.

Advantages and Disadvantages
Advantages - Highly reliable and accurate - Low cost - High resolution - Integrated electronics - Fuses optical and digital technology - Can be incorporated into existing applications - Compact size Disadvantages - Subject to magnetic or radio interference (Magnetic Encoders) - Direct light source interference (Optical Encoders) - Susceptible to dirt, oil and dust contaminates

Q: What is an encoder? A: An encoder is a sensor of mechanical motion that generates digital signals in response to motion. Q: What is the difference between absolute and incremental encoders? A: Absolute and incremental encoders are different in two ways: - Every position of an absolute encoder is unique - An absolute encoder never loses its position due to power loss or failure. Incremental encoders lose track of position upon power loss or failure Q: What is a channel? A: A channel is an electrical output signal from an encoder. Q: What is a quadrature? A: A quadrature has two output channels, with repeating squarewaves, which are out of phase by 90 electrical degrees. From the phase difference, the direction of rotation can also be determined. Q: What is an index pulse? A: The index pulse, also referred to as a reference or marker pulse, is a single output pulse produced once per revolution. Q: What other types of encoder technologies are there? A: There are two types of encoder technologies. - Optical: This type of technology uses a light shining into a photodiode through slits in a metal/glass disk. - Magnetic: Strips of magnetized material are placed on rotating discs and are sensed by Hall-Effect Sensors or magneto-resistive sensors. Q: What types of applications are encoders implemented in? A: They are frequently utilized in stepper motors, automation, robotics, medical devices, motion control and many other applications requiring position feedback. Q: Does any encoder disk (codewheel) work with any encoder module? A: No, each resolution and each disk diameter works with a different encoder module. Q: What is PPM? A: PPM stands for pulse per revolution in rotational motion for rotational motion and pulse per inch or millimeter for linear motion. Q: When can a single output channel be used in an incremental encoder? A: A single output channel for an incremental encoder can be used when it is not important to sense direction. Such applications make use of tachometers.

How to Select an Encoder
There are several important criteria involved in selecting the proper encoder: 1. Output 2. Desired Resolution (CPR) 3. Noise and Cable Length 4. Index Channel 5. Cover/Base Output The output is dependent on what is required by the application. There are two output forms which are incremental and absolute. Incremental output forms take form of squarewave outputs. For an application requiring an incremental encoder, the output signal is either zero or the supply voltage. The output of an incremental encoder is always a squarewave due to the switching of high (input voltage value) and low (zero) signal value. Absolute encoders operate in the same manner as incremental encoders but have different output methods. The resolution of an absolute encoder is described in bits. The output of absolute encoders is relative to its position in a form of a digital word. Instead of a continuous flow of pulses as seen by incremental encoders, absolute encoders output a unique word for each position in form of bits. Equivalent to 1,024 pulses per revolution, an absolute encoder is described to have 10 bits (210 = 1024). Desired Resolution (CPR) The resolution of incremental encoders is frequently described in terms of cycles per revolution (CPR). Cycles per revolution are the number of output pulses per complete revolution of the encoder disk. For example, an encoder with a resolution of 1,000 means that there are 1,000 pulses generated per complete revolution of the encoder. Noise and Cable Length When selecting the proper encoder for any application, the user must also take into account noise and cable length. Longer cable lengths are more susceptible to noise. It is crucial to use proper cable lengths to ensure the system functions correctly. It is recommended to use shielded, twisted-pair cables with preferably low capacitance value. The rating for capacitance value is normally in capacitance per foot. The importance of this rating is for well defined squarewave pulse outputs from the encoder rather than “jagged” or “saw-toothed” like pulses due to the interference of noise. Index Channel The index channel is an optional output channel which provides a once per revolution output pulse. This pulse allows for the user to keep track of position and establishes a reference point. This output channel is extremely valuable for incremental encoders when an interruption of power occurs. In instances with a power failure, the last sustained index channel can be used as a reference marker for a restarting point. Therefore, when such an occurrence takes place, an index channel can prove to be quite valuable in applications utilizing incremental encoders. Note: Absolute encoders do not have an issue with losing track of position in power loss situations due to every position being assigned a unique bit configuration. Cover/Base Cover and base options are considerations for application needs. Enclosed cover options help protect the encoder from dust particles. Base options play a significant role in large vibration environments. Such mounting options are transfer adhesives which stick directly on the back of the encoder to the mounting surface, molded ears for direct mounting. Anaheim Automation also offers various base options for mounting purposes. Anaheim Automation offers a selection of cover and base options to meet your application needs.

Physical Properties of Rotary Encoders
The key components of rotary encoders are the disk, light sources and detectors, and electronics. The disk contains a unique pattern of concentric etched circles and alternates between opaque and transparent segments. This pattern provides unique bit configurations and is used to assign specific positions. For every concentric ring in rotary encoders, there is a light source and light detector which identify lines etched on the disk. The electronics consist of an output device which takes the signal obtained from the sensor (light/detector source) to provide feedback of position and/or velocity. All of these components are enclosed in a single housing unit.

© 2018 Anaheim Automation, Inc. - All Rights Reserved