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Quadrus EZ Reader User’s Manual
Glossary of Terms
Input—A channel or communications line. Decoded data or a discrete signal that is
received by a device. See Output.
Integration—Exposure of pixels on a CCD or CMOS sensor.
Ladder Orientation—A bar code symbol in which the bars are parallel to the symbol’s
direction of travel.
LED—Light emitting diode. Often used as a strobe for medium speed objects.
Lens—A transparent piece of material with curved surfaces which either converge or
diverge light rays.
Machine Vision—The automatic acquisition and analysis of images to obtain desired data
for controlling a specific activity.
Multidrop—A communications protocol for networking two or more readers or other
devices with a concentrator (or controller) and characterized by the use of individual
device addresses and the RS-485 standard.
Noise—The same as static in a phone line or “snow” in a television picture, noise is any
unwanted electrical signal that interferes with the image being read and transferred by the
reader.
Normally Closed—A discrete output state that is only active when open.
Normally Open—A discrete output state that is only active when closed.
Object Plane—An imaginary plane at the object, which is focused by the optical system at
the image plane on the sensor.
Output—A channel or communications line. Data or discrete signals that are transmitted
or displayed by a device.
Parity—An error detection routine in which one data bit in each character is set to 1 or 0
(zero) so that the total number of 1 bits in the data field is even or odd.
Picket Fence Symbol Orientation—A bar code symbol in which the bars are perpendicu-
lar to the symbol’s direction of travel.
Pixel—Acronym for picture element. The individual elements in a digitized image array.
Port. Logical circuit for data entry and exit. (One or more ports may be included within a
single connector.)
Processing Time—The time used by a vision system to receive, analyze and interpret
image information. Often expressed in parts per minute.
Progressive Scan—A non-interlaced scan that doubles the number of visible picture lines
per field by displaying all picture lines at once.
Protocol. The rules for communication between devices, providing a means to control the
orderly flow of information between linked devices.
RAM—An acronym for Random Access Memory for storage and retrieval of data.
Read Cycle—A programmed period of time or condition during which the reader will
accept bar code symbol input.
Real Time Processing—In machine vision, the ability of a system to perform a complete
analysis and take action on one part before the next one arrives for inspection.