Manufacturing AUTOMATION

Glossary Terms
Terms that are used on the Manufacturing Automation website

Valid Requirements

Procedures, specifications, plans or policies which meet the needs of the customer(s) and are current, realistic, understandable, measurable, achievable and compatible with other requirements. When conformed to, valid requirements yield quality.

Value Added

Activities or work essential to ensure a product or service meets the needs of the customer.

Value engineering

a total approach to design that achieves improved performance and quality by stressing simplicity and integration of design and manufacturing techniques.


Principles or qualities which are worthwhile and govern the operation of total quality management.


a Value-Added Reseller.


A factor that can be altered, measured, or controlled.

Variable data

Numerical information that can be changed during application operation. It includes timer and counter accumulated values, thumbwheel settings, and arithmetic results.


Periodic or sporadic changes or deviations within a process.


A two-electrode semiconductor device with a voltage-dependant non-linear resistance that drops markedly as the applied voltage is increased. It is used to suppress transient voltage surges.


Visual basic for applications


Video Display Terminal.


A quantity that denotes both magnitude and direction. Vectors are commonly represented by a line segment with an arrow; the length represents the magnitude; the orientation in space and the placement of the arrow at one end of the line represents the direction.

Vector quantity

A quantity that denotes both magnitude and direction in relation to a given frame of reference. Examples of quantities that are vectors are displacement, velocity, force, and magnetic intensity.


A vector quantity that denotes both magnitude (e.g., speed) and direction in relation to a given frame of reference.

Velocity loop

A feedback control loop in which the controlled parameter is motor velocity. Usually uses a tachometer for a feedback device.


Variable-Frequency Drive.


Video Graphics Adapter. A video adapter introduced in 1987. The VGA duplicates all video modes of the EGA (Enhanced Graphics Adapter) and provides several additional modes.

VRC Vertical redundancy check. An error-checking method that adds a check or parity bit to each character in a message so the number of 1 bits, including the parity bit, in each character is odd (odd parity) or even (even parity).


The logical or conceptual view of something, which implies some sort of mapping function to get from conceptual to physical.

Vision systems

employ video cameras for inspection, verification, measurement, code reading and other purposes. Vision systems employ sophisticated pattern-recognition software to analyze the images they capture and compare it against defined patterns.

Voice recognition systems

Devices which are either portable and fixed station which use human speech as data input and translate it into machine recognizable codes or commands.