Di-soric ID-08, Руководство пользователя

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ID-08 / ID-09 High Performance Imager – User´s Manual
A-51
Appendices
Delimited — A delimited command or field is bracketed by predefined characters.
Decode Rate — The number of good reads per second ahieved by a reader.
Darkfield 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 a reader. 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.
Digital Signal Processor (DSP) — A VLSI chip designed for ultra-high-speed arithmetic
processing.
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.
DSP — See Digital Signal Processor .
EPROM — See Erasable Programmable Read-Only Memory .
Embedded Memory — Onboard memory device such as EPROM or flash.
End of Read Cycle — The time or condition at which the reader 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.
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 a symbol length
will be accepted.
Focal Distance — 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 .
Full Duplex — A communications system in which signals can travel simultaneously
between devices.