Microscan Quadrus Verifier, User Manual

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Quadrus Verifier User’s Manual
Glossary of Terms
Dot Ovality —The extent of oval distortion of directly marked 2D symbol elements.
DSP —Digital Signal Processing. See also Digital Signal Processor .
Dynamic Range —The difference between the minimum and maximum thresholds of
discernible images; the amount of usable signal.
Edge Enhancement —Image processing method to strengthen high spatial frequencies in
an image.
Element —The fundamental unit of data encodation in a linear or 2D symbol. A single bar,
space, square, dot, etc.
Embedded Memory— Onboard memory device such as EPROM or flash.
End of Read Cycle— The time or condition at which the reader stops expecting to receive
symbol information.
EPROM— Erasable, programmable read-only memory.
External Edge —Allows a read cycle to be initiated by a trigger signal from an object
detector when it detects the appearance of an object (rising edge). The read cycle ends
with a good read, a timeout, or a new trigger.
External Level —Allows a read cycle to be initiated by a trigger signal from an object
detector. The read cycle ends when the object moves out of the detector’s range.
Fill Factor —Percentage of pixel area used for light collection.
Firmware —Software that is hard-coded in non-volatile memory (ROM).
Fixed Pattern Damage— A measurement of the damage to a symbol’s finder pattern,
clock pattern, quiet zone, and any other fixed pattern in or adjacent to a symbol.
Fixed Symbol Length— Increases data integrity by ensuring that only one symbol length
will be accepted.
Focal Distance —In camera-based vision, the distance from the front of the camera to the
object being viewed. (In optics, the distance from the lens to the focal plane.)
Focal Plane —Usually found at the image sensor, it is a plane perpendicular to the lens
axis at the point of focus.
Focus —The point at which rays of light converge for any given point on the object in the
image. Also called the focal point.
Frame —The total area captured by an image sensor.
Frame Grabber —A device that interfaces with a camera and, on command, samples the
video, converts the sample to a digital value, and stores it in a computer's memory.
Front End System —The object, illumination, optics, and reader blocks of a vision system.
Includes all components useful to acquire a good image for subsequent processing.
FPGA —Field-Programmable Gate Array. A semiconductor device containing programmable
logic components and programmable interconnects.
Gain— The amount of energy applied to pixel gray scale values prior to output, expressed
in dB. Also, optimal signal strength.
Global Threshold —The reflectance level at which dark and light elements in a symbol
can be discriminated in a scan reflectance profile.
Good Read— The successful decoding of the information encoded in a symbol.