Glossary of Terms

An Absolute Encoder is an encoder that provides a unique output for each resolvable position...   Read more...

Back to Top

Encoder Accuracy is the difference between the target position and the actual position. It is...   Read more...

Back to Top

A Channel is an electrical output signal from an incremental encoder. Channels are designated...   Read more...

Back to Top

A Cycle refers to one complete four-state quadrature cycle. One quadrature cycle is generated...   Read more...

Back to Top

Cycle Error is the difference between the target (theoretical) position of the shaft and the...   Read more...

Back to Top

CPR is the number of full quadrature cycles per full shaft revolution (360 mechanical...   Read more...

Back to Top

Differential Output is an output employing a complementary channel for the standard encoder...   Read more...

Back to Top

A disk is the round mylar material used by US Digital on which is placed an evenly spaced...   Read more...

Back to Top

Duty Jitter is a variation from pulse width to adjacent pulse width.   Read more...

Back to Top

Eccentricity Error is the measurement in the error of a rotary encoder caused by an...   Read more...

Back to Top

An Electrical Degree (°e) is 1/360 of an electrical cycle. Electrical degrees are used in...   Read more...

Back to Top

An Encoder is an electro-mechanical device that translates physical motion into an electrical...   Read more...

Back to Top

An Encoder Module is an electronic component made by US Digital which incorporates an LED and...   Read more...

Back to Top

Frequency is the number of cycles per second which can be read by an encoder. Each encoder is...   Read more...

Back to Top

A Homing Cycle is the movement of an incremental encoder to find its index. This is helpful...   Read more...

Back to Top

A HubDisk assembly consisting of an aluminum hub and an optical encoder disk.   Read more...

Back to Top

An Inclinometer is a device that reports the angle of an object with respect to gravity....   Read more...

Back to Top

An Incremental Encoder is an encoder that provides information via a waveform output as...   Read more...

Back to Top

The Index is a unique location on an encoder disk or linear strip used as a reference point....   Read more...

Back to Top

Interpolation is the internal multiplication of a signal in an encoder providing a higher...   Read more...

Back to Top

IP Ratings identify the ability of an enclosure to resist intrusion. Common examples are IP64...   Read more...

Back to Top

Line Count is the number of equally spaced lines on a linear strip or disk. The space between...   Read more...

Back to Top

A Line Driver is a circuit designed to increase the maximum recommended cable length for...   Read more...

Back to Top

A Linear Strip is the mylar material used by US Digital on which is placed an evenly spaced...   Read more...

Back to Top

A Magnetic Encoder is an encoder that uses a magnetic code wheel to provide an...   Read more...

Back to Top

The Moment of Inertia is the point at which the rotational force being applied to a shaft...   Read more...

Back to Top

Noise is any unwanted electrical signal that can potentially interfere with a desired signal....   Read more...

Back to Top

Open Collector Output is an output that allows the user to set the voltage level of the output...   Read more...

Back to Top

An Optical Encoder is an encoder using a light source, detector and interrupting medium...   Read more...

Back to Top

Output Waveforms are the relationship of the output signals to each other, normally shown in a...   Read more...

Back to Top

A Phase the delay in time or degrees between the rising edge of channel A and the rising...   Read more...

Back to Top

Phase jitter is the variation between the rising edges of channel A and channel B from one...   Read more...

Back to Top

Phase Relationship identifies which channel (A or B) leads (goes high first) the other channel...   Read more...

Back to Top

A Phased Array is a pattern of photodiodes used on US Digital encoders to detect several lines...   Read more...

Back to Top

See Cycle Error   Read more...

Back to Top

A Pseudo-Absolute Encoder is an incremental encoder used as an absolute encoder on single turn...   Read more...

Back to Top

PPR is the term US Digital uses to refer to the number of pulses after 4x quadrature...   Read more...

Back to Top

Quadrature is the most common digital incremental encoder output. It uses two channels...   Read more...

Back to Top

Resolution relates to the quantity of increments an encoder has in one rotation (for a rotary...   Read more...

Back to Top

Revolution is one complete rotation of the encoder shaft, 360 mechanical degrees....   Read more...

Back to Top

Shaft Axial Play is the movement of the shaft in the axial direction. US Digital states...   Read more...

Back to Top

Shaft Loading is the specification used on shafted encoders and refers to the force applied...   Read more...

Back to Top

Shaft Runout is the deviation of a shaft from true circular rotation. This can be caused by a...   Read more...

Back to Top

Single-Ended Output is the most basic kind of output on an encoder. Each channel only has one...   Read more...

Back to Top

Stiction is a combination of the words stick and friction. Stiction exists when the...   Read more...

Back to Top

Symmetry is the relationship of the on time to the off time (x,y) for any encoder...   Read more...

Back to Top

TIR is a measurement of shaft runout—deviation of a shaft from true circular rotation....   Read more...

Back to Top