Microscan MS-4Xi, User Manual, Page: 356 / 360

A-36
MS-4Xi Imager User’s Manual
Glossary of Terms
Charge-Coupled Device (CCD) — A semiconductor device with an array of light-sensitive
elements that converts light images into electrical signals.
Check Character — A Modulus 43 or Modulus 10 character that is added to encoded
symbol data for additional data integrity.
CMOS — See Complementary Metal Oxide Semiconductor .
Complementary Metal Oxide Semiconductor (CMOS) — Like CCDs, CMOS imagers
include an array of photo-sensitive diodes, one diode within each pixel. Unlike CCDs, however,
each pixel in a CMOS imager has its own individual amplifier integrated inside.
Connector — A plug or socket on a device or cable providing in/out connectivity for various
circuits and pins.
Concentrator — Intermediary device that relays data from imagers to a host and commands
from the host to the imagers or other devices.
Counter — Memory space allocated to keep track of imager events.
DAC — See Digital-to-Analog Converter .
Daisy Chain — Linkage of primary and secondary imagers allowing data to be relayed up
to the host via auxiliary port connections.
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.
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 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.
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.
DMA — See Direct Memory Access .
DSP — See Digital Signal Processor .
Dynamic Range — The difference between the minimum and maximum thresholds of
discernible images; the amount of usable signal.