Signals and PLC · Glossary

What is an Encoder?

pulses per revolutionSignals and PLC

An encoder converts shaft rotation into pulses or a digital position, used to measure speed and position.

Encoder Explained

Incremental encoders give a set number of pulses per revolution (PPR), often on two channels A and B for direction. Absolute encoders give a unique code for each position, often Gray coded.

Speed is calculated from pulse frequency.

Encoder Formula

RPM = f × 60 ÷ PPR

f	pulse frequency (Hz)
PPR	pulses per revolution

Example: 1024 PPR at 25,600 Hz: 1500 RPM.

Calculators for Encoder

CalculatorEncoder RPM CalculatorFree online calculator with formula and worked example.CalculatorGray Code ConverterFree online calculator with formula and worked example.

Frequently Asked Questions

What is an Encoder?

An encoder converts shaft rotation into pulses or a digital position, used to measure speed and position.

Incremental or absolute?

Absolute keeps position through power loss; incremental needs homing.

What is quadrature?

Two channels 90° apart, giving direction and up to four counts per pulse.

Learn more on the blog

Introduction to number systems

A practical guide on instrumentationblog.in with more detail on encoder and how it is applied on real plants.

Read Full Article

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