Motor shaft movement in or out, relative to the ends of the motor. Often motors that use roller or sleeve bearing construction have more axial shaft movement. Most Avtron modular encoders tolerate +/- 0.050" of axial movement maximum. Use hollow shaft encoders for high axial movement motor styles, such as MD motors. Most competitors’ modular encoders tolerate much less axial movement than Avtron products.

Also known as complementary outputs. To ensure that signal noise does not cause errors between the encoder and the controller, many encoders output signals that are driven in exactly opposite directions: when A goes high, A NOT goes low (, ); when A goes low, A NOT goes high. Controllers which see a transition in A, but not in the A NOT signal, would report a quadrature error.

Also known as contaminants, such as water, dirt, dust, oil, and other compounds which enter an encoder through seal failure and can cause optical errors. If the contamination is abrasive, it can also cause bearing failures in the encoder. Modular encoders are very resistant to contamination as they use magnetoresistive sensors and have no bearings.

Also known as Flameproof, explosion protected equipment has additional protection/safety enhancements for use in explosive atmospheres. Explosion Protected devices maybe placed directly into hazardous areas within their nameplate rating. No additional equipment is required if installation instructions are followed properly. By comparison, Intrinsically Safe devices may require the use of additional, external protection/current limiting devices outside of the hazardous area. Avtron offers hollow shaft M6C Explosion Protected encoders.

Also known as Explosion Proof, flameproof encoders have additional protection/safety enhancements for use in explosive atmospheres. Flameproof encoders maybe placed directly into hazardous areas within their nameplate rating. No additional equipment is required if installation instructions are followed properly. By comparison,
Intrinsically Safe encoders may require the use of additional, external protection/current limiting devices outside of the hazardous area. Avtron offers hollow shaft M6C Flameproof encoders.

An encoder that produces pulses in proportion to distance moved or rotated. Incremental encoders can also have a marker pulse Z, Z NOT (, ) once per revolution to provide a position reference. Avtron produces a full range of incremental rotary encoders.

Is a system designed to improve equipment safety by limiting spark energy values in equipment used in hazardous areas.  Intrinsic Safety is a different system of protection than Explosion Proof or Flameproof.  Many Explosion Proof and Flameproof encoders can be replaced with Intrinsically Safe encoders, provided the installation instructions are followed correctly and the system is compliant with the approved installation drawing.  Intrinsically safe Avtron XR encoders are available in Level 1 protection and Level 2 protection. 

The chip or output circuit that forms the electrical pulses output from the encoder. Avtron has extremely advanced line driver technology to prevent damage from overvoltage and short circuits. Avtron offers optional high-power line drivers to permit Avtron encoder signals to travel farther down long wires to remote controller/drive locations without the need for repeaters or amplifiers.

Encoders produce pulses that create transitions up and down in a DC voltage. Each transition is called a line. Quadrature encoders with their two channels produce four times as many lines as pulses. Some drive products can be set to count lines in one direction (up/down) or all directions, creating more counts in the drive than the rated PPR (pulses per revolution) of the encoder.

Magnetic and magnetoresistive encoders typically use a magnetized rotor with north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions, and these are the counts or pulses generated by the encoder. Magnetic encoders withstand dirt, dust, water, and temperature changes far better than optical encoders.

A magnetized disk with multiple north and south poles lined up around the perimeter of the disk. A magnetoresistive sensor detects the transitions and generates the pulses generated by the magnetic encoder.

A sensor that detects the magnetic poles on an encoder's magnetic rotor and transforms them into pulses. Avtron magnetoresistive (MR) sensors use advanced technology to reject external magnetic signals such as brake solenoids and motor magnetic fields. MR sensors enable Avtron magnetic encoders to ignore dirt, oil, water, and other contaminants.

The Marker Pulse occurs once per revolution. The purpose of the marker pulse is to provide a repeatable home position location for positioning applications. The marker pulse is often abbreviated as "ØZ" or "Z" in the USA and "C" or "N" in Europe.

Magnetoresistive (MR) sensors are used in Avtron encoders to provide high accuracy and superior reliability versus optical sensing systems.  For more information on magnetoresistivity:  Wiki:  http://en.wikipedia.org/wiki/Magnetoresistive

An Optical Disk is typically a glass, metal, or plastic disk with fine lines or slots etched around the perimeter that interrupt the beam of light from the light source to an optical sensor. Optical disks can be quite fragile. Avtron uses only shatterproof optical disks with Wide-Gap technology.

Optical Errors include false pulses, missed pulses, and quadrature errors that are generated when there is any type of contamination (dirt, oil, water, condensation) on the optical disk.

Pulses Per Revolution. Most Avtron encoders output quadrature pulses, with four times as many lines as pulses. Often lines can be counted in the drive/speed controller for higher resolution applications.

Pulses are also known as counts and are the low voltage output transitions which indicate movement of the encoder. Encoders are rated by resolution or PPR (pulses per revolution). Pulses are not the same as lines.

Resolution describes how many individual slices or positions can be reported by an incremental or absolute encoder.  For incremental encoders the number of PPR (pulses per revolution) expresses resolution; for absolute encoders, PPR, or counts per turn or bits of resolution may be listed.

The disk-shaped portion of the modular encoder that is mounted on the motor shaft. Avtron modular encoders use magnetic rotors.

When the rotating disk in an encoder contacts the sensor (optical or magnetic/magnetoresistive), it damages or destroys the sensor. Sensor crashes can be caused by excessive vibration, shaft runout, or alignment problems in encoder mounting. Avtron encoders feature Wide-Gap technology to eliminate sensor crashes.

Severe Duty encoders have the best ability to withstand temperature cycling, extreme temperatures, contaminants, bearing loads and physical abuse.

The undesirable electrical current flow common to motors controlled by variable speed drives. This current attempts to circulate within the motor or discharge to ground. Avtron encoders are protected against shaft currents.

The wobbling motion produced by a shaft that is not perfectly true and straight. Shaft runout is often abbreviated T.I.R. (Total Indicated Runout).

Often, to produce precise stub shaft, modular encoder, or foot mount installation, shims are placed between the two items to be aligned. Avtron encoders are designed to eliminate the need for shimming. Many competitors’ modular encoders still require shimming for proper operation.

The portion of the shaft (often on the non-drive end of the motor) used to mount an encoder. To add an encoder to a motor or other shaft that lacks enough extra shaft length to install the encoder, an additional shaft length is added. The stub shaft is threaded into the center of the motor shaft, or the existing motor shaft is enclosed in a sleeve that grips the shaft. Avtron offers many standard and custom stub shafts.

UL Listed Avtron encoders can be directly applied to any hazardous duty application which requires Class and Division, Class and Zone or AEX certification.  Note that UL Listing is a different system than ATEX or IECEx.  Ensure the model you select has the UL listing which meets the application requirements.

Avtron encoders use special optical sensors and magnetoresistive sensors, combined with proprietary circuit designs to allow the sensor to be located much farther from the magnetic rotor or optical disk. This eliminates sensor crashes and makes mounting easy and forgiving of mechanical variation.