Omron MicroHAWK V320-F User Manual page 488

Appendices
Decode — A Good Read. The successful interpretation and output of the information encoded in a
symbol.
Default — Restores ROM or flash settings, initializes serial commands and resets all counters.
Delimited — A delimited command or field is bracketed by predefined characters.
Decode Rate — The number of good reads per second ahieved by an imager.
Dark Field Illumination — Lighting of objects, surfaces, or particles at very shallow or low angles, so
that light does not directly enter a reader's optical hardware.
Depth-of-Field — The in-focus range of an imaging system. Measured from the distance behind an
object to the distance in front of the object with all objects appearing in focus.
Diffused Lighting — Scattered soft lighting from a wide variety of angles used to eliminate shadows and
specular glints from profiled, highly reflective surfaces.
Digital-to-Analog Converter (DAC) — A VLSI circuit used to convert digitally processed images to
analog for display on a monitor.
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Digital Imaging — Conversion of an image into pixels by means of an Analog-to-Digital Converter
where the level of each pixel can be stored digitally.
Digital Signal Processor (DSP) — A VLSI chip designed for ultra-high-speed arithmetic processing.
Often imbedded in a vision engine.
Discrete I/O — Inputs and outputs characterized by discrete signal transitions from one voltage level to
another so that digital switching can occur.
Direct Memory Access (DMA) — A capability provided by some computer bus architectures that allows
data to be sent directly to memory from an attached device.
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 the image.
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.
Frame — The total area captured in an image sensor while the video signal is not blanked.
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MicroHAWK V320-F / V330-F / V420-F / V430-F Barcode Reader User Manual