Glossary of rotary encoder！

When selecting encoders， the bellow five parameters are neccessary:

(number of output pulses per revolution P / R); signal output form (signal and signal output form large ones); supply voltage (5 ~ 12V low voltage, 12 ~ 24 high voltage); shaft diameter (mm); dimensions (mm). (Example: User Requirements Order 100 pulse, three-way signal line driver output voltage of 5V, shaft diameter 6mm, 38mm in dimensions.

Glossary of rotary encoder

Absolute Encoder - provides the shaft position in a bit configuration and is able to maintain or provide absolute position even after instances of power loss/failure.

Accuracy – difference in distance between the theoretical and the actual position.

Cycles Per Revolution (CPR) - Cycles per revolution are the number of output pulses per complete revolution of the encoder disk

Encoder - is a sensor of mechanical motion that generates digital signals in response to motion.

Incremental Encoder - device that provides a train of pulses due in response to mechanical motion. The output of this encoder is in form of a squarewave.

Index - a separate output channel which provides a single pulse per shaft revolution. It can be used to establish a reference or marker for a starting position.

Interpolation - is the method of increasing the resolution of an encoder. This method allows for the encoder to produce a higher resolution output without increasing the overall size of the disk and encoder.

Line Driver - is a sourcing output. This means that when in ‘ON' state the line driver will supply Vcc and in the ‘OFF' state the driver will float. A sinking input is required for line driver applications.

Open Collector - is a sinking output. In the ‘OFF' state, an open collector will be grounded and in the ‘ON' state, the open collector will float. A sourcing input is required for open collector applications.

Pulses Per Revolution (PPR) - the total number of pulses produced per full revolution of the encoder shaft.

Push-pull - is a combination between a line driver and an open collector. In the ‘OFF' state it will be grounded and in the on ‘ON' state it will supply Vcc.

Quadrature Encoder - two output channels which are out of phase by 90 electrical degrees. From the phase difference, the direction of rotation can also be determined.

Resolution – number of line increments on a disk. Resolution for incremental encoders is often referred to as cycles per resolution and for absolute encoders it is in terms of bits.

Single Channel Encoder – has only one output channel and is used in speed applications.

Squarewave - a repetitive waveform corresponding to high and low signals.

Previous：Where are Rotary Encoders Used?
Next：Some advantages of incremental encoders