12 VDC Automotive Power Option

120 VAC Power Option

4469 Line Driver

5PY Adapter

7272 and 7273

Absolute Encoder

Accuracy

The difference between the theoretical position and the actual position indicated by the encoder.

AE087 and AE100 Flexible Shaft Couplings

Anti-Jitter

APR-F040 Aperture (see F Series Photo-Electronics)

Automotive Power Option

Axial Load (see also Bearing Life)

A constant load applied along the axis of the encoder bearing. This hypothetical value is used to calculate bearing life.

Bearing Life (L10)

The number of revolutions (or hours at some given constant speed) that 90% of a group of apparently identical ball bearings will complete or exceed before the first evidence of fatigue develops assuming certain conditions. This value can be used as a starting point for determining mean-time-before-failure of an encoder. Actual operating conditions could significantly influence this value.

Bi-directional (See Quadrature)

Binary Coded Decimal (BCD)

A binary coding scheme used by displays to represent decimal numbers. For example, a 4-bit BCD code word encodes one digit for a 7-segment display.

Blind Bore

A hollow shaft encoder with a shaft bore that extends only partially through the encoder.

Cable Assemblies

CE Mark

Centimeters per Pulse

CLS - Incandescent Light Source (see D Series and F Series Photo-Electronics)

Complementary Outputs (see also Differential Line Driver)

Two identical encoder output signals where one signal is electrically inverted from the other. Used in pairs these convey a single stream of pulse output to a PLC or other control device that uses differential line driver inputs.

Connectors

Couplings ( Flexible,  Rigid )

Cube Style Encoder (see also RS and RS-P encoders)

A de facto industry standard encoder that has a 2.25" x 2.25" x 2.25" cube shaped housing.

Current Sinking Output

Current Sourcing Output

D Series Light Sources and Receivers

Data Ready Signal

Differential Line Driver

Direction Indicator

DS-F0 Sensor (see F Series Photo-Electronics)

Dual Outputs (see also Quadrature)

Duty Cycle

The total time to complete one on/off cycle for a pulse output.

ECCI

Electronic Counters & Controls, Inc. Many modified Photocraft encoders can be substituted for ECCI encoders (see modified versions of the model RJ and RS encoders)

Encoder

An electro-mechanical device that translates mechanical shaft rotation into electrical signals that can be used by a PLC or other control device to control or determine position, velocity, acceleration, or direction. (See also: Absolute Encoder and Incremental Encoder)

Enhanced AJ Feature

Environmentally Sealed

An encoder that includes a shaft seal, O-ring and gasket seals to prevent moisture from penetrating into the encoder housing (see the RJ incremental encoder, and R30/SR30 absolute encoder)

ESD Protection

Extension Cable

F Series Light Sources and Receivers

Flange Adapter

A 2.5" square mounting adapter for RG or RJ incremental encoders (MB-FL).

Flexible Mounting Bracket

Flexible Shaft Coupling

Gray Code

A reflective binary code originally devised by Frank Gray of Bell Laboratories. It has the characteristic that only one bit changes between adjacent code words. When used within an absolute encoder it eliminates the possibility of ambiguous outputs that could occur if multiple bits were attempting to change simultaneously, thus greatly simplifying the encoder’s design.

Hollow Shaft Encoder

HRL and HRL-P Hollow Shaft Encoders

HRS and HRS-P Hollow Shaft Encoders

HS20 and HS20-P Hollow Shaft Encoders

HS25 and HS25-P Hollow Shaft Encoders

ILS and ILSH - Infrared Light Source (see D Series and F Series Photo-Electronics)

Incremental Encoder (see hollow shaft encoders, programmable encoders, shaft encoders, and wheeled encoders)

An encoder that generates a fixed number of square wave pulses for each revolution of the shaft. By counting pulses, a PLC or other control device can determine velocity, relative position, or relative movement of the shaft.

Index Pulse (see Zero Marker)

Interrogation Rate

Koyo Adapter

A mounting adapter for RG or RJ encoders, making them interchangeable with Koyo encoders.

Line Driver

Incremental encoders can be supplied with various output circuits including: RS422 differential line driver, 4469 line driver, and SN74265 line driver. These are typically used to provide error-free output pulses in electrically noisy environments or over long transmission lines. They must be used with a line receiver of the same type.

Logic Levels

MB-085 Coupling

MB-5PY Adapter

MB-75 , MB-76, MB-78 Adapters

MB-FB1 Flexible Mounting Bracket

MB-FB2 Flexible Tether

MB-FB3 Flexible Mounting Bracket

MB-FL Adapter

MB-FL3 Adapter

MB-FL4 Adapter

MB-FL5 Adapter

MB-FL6 Adapter

MB-KOYO Adapter

MB-RD and MB-RD2 Mounting Brackets

MB-UB1 RH Encoder Under-belt Counterweight Mounting

MB-UB1A RH Encoder Under-belt Counterweight Mounting with dual weights

MB-UB2 Offset Mounting for Wheeled Encoders

MB-UB3 RH Encoder Under-belt Spring Mounting

MB-UB4 RH Encoder Under-belt Spring Mounting

Measuring Wheels

Precision ground wheels that can be attached to an encoder shaft for linear measuring applications. These are typically used on conveyor systems for improved performance over shaft mounted encoders.

Micro-Change connector

See M131 Modification

Minimum Speed Indicator

Modifications

MR30 / MR31 Modular Absolute Encoders

Multi-Turn Absolute Encoder

An absolute encoder that internally consists of a single turn absolute encoder that provides angular position of the shaft, and a gear-reducer and another single turn absolute encoder that indicates the revolution number. For example, a 16-bit multi-turn encoder might consist of a 10-bit encoder that provides 1024 values per shaft revolution, and a 6-bit encoder that can indicate 64 turns of the shaft. Photocraft does not manufacture multi-turn encoders.

MW-1 and MW-30 Measuring Wheels

Natural Binary

A binary coding scheme used by computers and PLCs to represent integer numbers.

Non-contact Potentiometer

The SR12 with 0-10 vdc analog output can offer a high reliability option in place of a standard potentiometer.

Open Collector

Output Code

The position indicating code generated by an absolute encoder.

Output Current

The maximum current that can be sinked or sourced by each output.

Output Protection (see ESD Protection, Short Circuit Protection, and Surge Protection)

Output Waveform

The description of one or more pulse outputs from an incremental encoder. Nominally a 50/50 duty cycle, square wave is generated for each pulse output. The waveform is further described by the following parameters: Pulse On-Off Ratio, Pulse Interval Jitter, Quadrature Deviation, Pulse Rise Time, Pulse Fall Time, Voltage (high), Voltage (low), and Index Pulse

Over-Belt Mounting (see Y-1 yoke assembly)

Facilitates mounting the model RH wheeled encoder to ride above the conveyor belt.

Parallel Outputs

Phase (see also Quadrature)

The electrical degrees of displacement between two encoder outputs having the same pulses per revolution.

PMR Series Logic Level Receivers

PPI (Pulse Position Indicator)

A material handling industry name for an RH wheeled encoder.

Program

Programmable Encoder

PTR and PTRH Photo-Receivers (see D Series and F Series Photo-Electronics)

Pulse Fall Time

For the pulse output of an incremental encoder it is the time during which a pulse changes from 90% to 10% of the difference between its amplitudes, going from logic one to logic zero.

Pulse Interval Jitter

For the pulse output of an incremental encoder it is the band within which lie all of the transitions in the same direction of a signal through a specified amplitude. This is a dynamic value determined at one or more specified speeds.

Pulse On-Off Ratio

For the pulse output of an incremental encoder it is the period during which the waveform is above the midpoint of its amplitude excursion to the period during which it is below this value, at a specified speed.

Pulse Position Indicator (PPI)

A material handling industry name for an RH wheeled encoder.

Pulse Rate

For the pulse output of an incremental encoder it is the number of pulse intervals per unit time of an output signal at a specified speed.

Pulse Rise Time

For the pulse output of an incremental encoder it is the time during which a pulse changes from 10% to 90% of the difference between its amplitudes, going from logic zero to logic one.

Pulses per Foot (PPF) (conveyor applications)

Pulses per Meter (PPM) (conveyor applications)

Pulses per Revolution

Push/Pull Output

A general purpose circuit capable of either sourcing or sinking up to 50ma of current per output for any incremental encoder and 5ma per output for absolute encoders, and is compatible with most motion control equipment.

Quadrature

Quadrature Deviation

For an incremental encoder, quadrature deviation is the difference between quadrature and the actual displacement expressed in electrical degrees.

R20 and R20-P Series 20 Shaft Encoders

R30 Absolute Encoder

Radial Load (see also Bearing Life)

A constant load applied perpendicular to the axis of the encoder bearing. This hypothetical value is used to calculate bearing life.

RBX Shaft Encoder

RC Shaft Encoder

Resolution

RG Shaft Encoder

RH and RH-P Pulse Position Indicator Encoders

Rigid Shaft Coupling

RJ Shaft Encoder

RL and RL-P Shaft Encoders

Rotation

RS and RS-P  Cube Style Shaft Encoders

RS422 (see also Differential Line Driver)

An E.I.A. standard balanced voltage digital interface circuit well suited to high data rates, over long distances and through noisy environments. It includes differential transmission that nullifies the effects of ground shifts and noise signals which appear as common mode voltages on the transmission line.

Serial Asynchronous Outputs

Serial Synchronous Outputs

Shaft Encoder

Short Circuit Protection

Single Output

Single Turn Absolute Encoder

An encoder that generates a multi-bit binary code word indicating the angular position of the shaft. As the shaft is rotated through one complete revolution, the encoder generates some number of unique position codes depending on its resolution. The same output codes are repeated for each successive shaft revolution, such that it is possible to determine the angular position of the shaft but not the number of times it has rotated.

Speed Indicator (see Minimum Speed Indicator)

SR12 Abolute Encoder

SR30 / SR31 Absolute Encoders

Supply Current

The maximum current consumption by the encoder excluding output current (measured when the outputs are not connected).

Supply Voltage

The AC or DC operating voltage of the encoder.

Surge Protection

Tachometer (also known as "Tach")

A common name for a model RH wheeled encoder.

TPU-H5 Tachometer Pickup

Triac Output (see also 120 VAC Encoder Option)

Triple Outputs

Under-Belt Mounting (see MB-UB1 Under-belt Mounting)

Facilitates mounting the model RH wheeled encoder to ride under the conveyor belt.

Unidirectional (see Single Output)

VLS and VLSH Visible Light Sources (see D Series and F Series Photo-Electronics)

Voltage (high)

The minimum DC offset below the input supply voltage for the high level of a square wave output pulse.

Voltage (low)

The maximum DC offset above zero volts for the low level of a square wave output pulse.

Wheeled Encoder

Y-1, Y-2A, or Y-3 Yoke Assembly

Y-1G Yoke Assembly

Yoke Assembly (Y-1,Y-2A, Y-3 and Y-1G)

Zero Marker

Zero Speed Switch (see Minimum Speed Indicator)

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Copyright © 2008 Photocraft Inc
Last modified: May 12, 2008