Products & Solutions
Optical Rotary Encoders
Magnetic Rotary Encoders
Hazardous Area Encoders
Non Contact Encoders
View All Accessories
Condition Monitoring Overview
OnSite System Overview
OnSite Analysis Tools
Condition Monitoring Applications
Fans and Blowers
Dust Collectors and Air Handlers
Cranes and Hoists
Aerospace & Defense
Off Highway Vehicles
Oil & Gas
Measuring Conveyor Speed
Measuring Angles with Encoders
Measuring Linear Distance
Measuring with Draw Wire Encoders
Measuring Position with Encoders
Service & Support Overview
Competitor Parts List
Discontinued Encoder Guide
Product Manuals & Installation Guides
Featured Crossover Guides
Avtron Encoder Crossovers
DRC Encoder Crossovers
Sick-Stegmann Encoder Crossovers
Allen Bradley Encoder Crossovers
Accu-coder Encoder Crossovers
BEI Encoder Crossovers
Koyo Encoder Crossovers
How to Choose Feedback
Encoder Issues and Troubleshooting
White Paper Downloads
Power Point Downloads
How to Specify a Resolver
Draw Wire Encoders
Hall Effect Encoders
Encoder Accuracy vs Resolution
Encoder Wiring Best Practices
Single-Turn vs Multi-Turn Encoders
How to Split an Encoder’s Signal
Troubleshoot Encoder Signal Issues
An incremental encoder can be used in positioning and motor speed feedback applications which includes servo/light, industrial or heavy-duty applications.
An incremental encoder provides excellent speed and distance feedback and, since there are few sensors involved, the systems are both simple and inexpensive. An incremental encoder is limited by only providing change information, so the encoder requires a reference device to calculate motion.
An incremental encoder provides a specified amount of pulses in one rotation of the encoder. The output can be a single line of pulses (an “A” channel) or two lines of pulses (an “A” and “B” channel) that are offset in order to determine rotation. This phasing between the two signals is called quadrature. Learn more about quadrature encoder output here.
The typical assembly of an incremental encoder consists of a spindle assembly, PCB, and cover. The PCB contains a sensor array that creates just two primary signals for the purpose of position and speed.
Optionally, additional signals can be provided:
An index or ‘Z’ channel can be provided as one pulse per revolution signal for homing and pulse count verification on the A and/or B channels. This index can be gated to either A or B in their various states. It can also be un-gated and vary in width.
Commutation (U, V, W) channels can also be provided on some encoders. These signals are aligned to the commutation windings found on servo motors. They also ensure that the drive or amplifier for those motors apply current to each winding in the correct sequence and at the correct level.
Resolvers are electro-mechanical precursors to encoders, based on technology going back to World War II. An electrical current creates a magnetic field along a central winding. There are two windings that are perpendicular to each other. One winding is fixed in place, and the other moves as the object moves. The changes in the strength and location of the two interacting magnetic fields allow the resolver to determine the motion of the object.
The simplicity of the resolver design makes it reliable in even extreme conditions, from cold and hot temperature ranges to radiation exposure, and even mechanical interference from vibration and shock. However, the forgiving nature of resolvers for both origin and application assembly comes at the expense of their ability to work in complex application designs because it cannot produce data with enough accuracy. Unlike incremental encoders, resolvers only output analog data, which can require specialized electronics to connect with.
Absolute encoders work in situations where accuracy for both speed and position, fail tolerance, and interoperability matters more than system simplicity. The absolute encoder has the ability to "know where it is" in reference to its position in case of system power-down and restart if the encoder were to move during a power-down.
The absolute encoder itself understands the positioning information – it doesn’t need to rely on outside electronics to provide a baseline index for the encoder position. Especially when compared to resolvers and incremental encoders, the obvious strength of absolute encoders is how their positioning accuracy affects the overall application performance, so it is typically the encoder of choice for higher precision applications such as CNC, medical and robotics
An Incremental Encoder is designed to be versatile and customizable to fit a wide variety of applications. The three broad categories of applications based on environment are:
See our most popular incremental encoder models: