Technical Blog

Absolute and Incremental Encoders

An encoder is a device used to convert mechanical motion or position into an electrical signal to monitor or control machinery or equipment. They are widely used to measure motion, position, and velocity of rotating components such as motors, wheels and gears, and are commonly used to provide real-time feedback to a control system, allowing it to adjust and maintain precise operation.

Types of encoder

There are two main types of encoder, absolute and incremental, and both can be used in a variety of applications including robotics, medical, automotive, aviation, process and packaging, and agriculture. Absolute encoders provide a unique digital code for each position, so the control system always knows the exact position of the component. They will not lose any data when power is cut and will continue to measure where it left off. Incremental encoders provide a series of pulses that are counted to determine the position of the component, meaning it measures changes in position rather than providing absolute values.  It requires an electronic controller to keep track of the changes since the encoder was last reset.

What problems do encoders help solve?

  1. Accurate positioning of moving parts: in MRI machines, for example, encoders provide position feedback for the magnetic field gradient coils and the patient table, ensuring precise imaging.
  2. Closed-loop feedback: to continuously monitor the performance of the machinery and adjust it accordingly. For example, if the encoder detects that a motor is running too fast, the control system might reduce the voltage of current running to it to slow it down.
  3. Velocity control: to control the speed of rotating components in machinery such as motors pumps, and fans.
  4. Consistency and quality: for example, positioning and accuracy of printing, labelling, marking and coding systems to ensure consistency and continuous quality of the packaging process in automated equipment manufacturing lines.
  5. Safety: real-time feedback on the position and speed of moving parts can be used to trigger an emergency stop system, helping ensure the safe operation of machinery.

Encoders are versatile sensors used in a wide range of applications including autonomous vehicles, medical devices, robotics and industrial IoT. Some newer and emerging applications include use in drones to control the movement and ensure it stays on course,  and virtual and augmented reality to help create a more immersive and realistic experience.

We are the exclusive UK distribution partner for Wachendorff Automation, the German supplier of rotary and linear encoders, and encoder systems. This includes the new WDGN series of incremental rotary encoders that allow users to freely program the encoder line count and set-up characteristics using an Android NFC App. Wachendorff is well known for the reliability and accuracy of its products, and all its encoders come with a 5 year warranty and comprehensive technical support. To discuss the range of options available and for help in selecting and integrating the right encoder for your application, please contact us on +44 (0)1327 351 004 or


Article published on: 16/05/2023

Article last updated on: 16/05/2023