Microscan EZ Match, Руководство пользователя

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EZ Match User’s Manual
A-33
Appendices
Embedded Memory — Onboard memory device such as EPROM or flash.
End of Read Cycle — The time or condition at which the imager stops expecting symbol
information to decode.
Erasable Programmable Read-Only Memory (EPROM) — A memory chip that retains
data when its power supply is turned off; “non-volatile 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.
Falling Edge — A change of state (to inactive) associated with a level trigger.
Field-Programmable Gate Array (FPGA) — A semiconductor device containing programmable
interconnects and logic components.
Fill Factor — Percentage of pixel area used for light collection.
Firmware — Software hard-coded in non-volatile memory ( ROM ), and closely tied to
specific pieces of hardware.
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 — Any given point in an image at which light converges; the focal point.
FPGA — See Field-Programmable Gate Array .
Frame — The total area captured in an image sensor while the video signal is not blanked.
Frame Grabber — A device that interfaces with a camera and, on command, samples the
video, converts the sample to a digital value and stores that in a computer's memory.
Front End System — The object, illumination, optics and imager blocks of a vision system.
Includes all components useful to acquire a good image for subsequent processing.
Full Duplex — A communications system in which signals can travel simultaneously
between devices.
Gain — The amount of energy applied to pixel gray scale values prior to output, expressed
in dB; optimal signal strength.
Good Read — A decode. The successful scanning and decoding of the information
encoded in a bar code symbol.
Gradient — The rate of change of pixel intensity (first derivative).
Gray Scale — Variations of values from white, through shades of gray, to black in a digitized
image with black assigned the value of zero and white the value of one.
Half Duplex — A communications system in which signals can travel between devices in
both directions, but not simultaneously.