Learning
Barcode Terminology 101
Alternating Current (AC)
- In electricity, alternating current (AC) occurs
when charge carriers in a conductor or semiconductor
periodically reverse their direction of movement. Household
utility current in most countries is AC with a frequency of
60 hertz (60 complete cycles per second), although in some
countries it is 50 Hz. The radio-frequency (RF) current in
antennas and transmission lines is another example of AC.
Access Point - In
networking, an access point is a bridge. An access point
converts RF to Ethernet. Allows RF end devices such as
handheld, VMUs, and other data collection computers and
PC’s, PDAs, etc. to connect to a LAN.
Automated Identification & Data
Capture (AIDC) - The AIDC industry, synonymous
with the Automatic Data Collection (ADC) industry utilizes
hardware such as handheld, vehicle mounted and stationary
data collection computers, wireless networks, scanners, and
printers, and software such as ERP, WMS, etc. to collect
data. This is done by using RFID, Touch Memory and barcodes.
Using these tools allows us to better perform warehouse
management, asset tracking, work in process tracking, route
delivery, retail sales, inventory management, and many other
tasks.
Automatic Identification
Manufactures (AIM) – AIM, Inc. is the global
trade association for the Automatic Identification and Data
Capture (AIDC) industry. Their members are manufacturers or
service providers of technologies such as radio frequency
identification (RFID), barcode, card technologies (magnetic
stripe, smart card, contact less card, optical card),
biometrics, and electronic article surveillance (EAS).
American National Standards
Institute (ANSI) - ANSI is the primary
organization for fostering the development of technology
standards in the United States. ANSI works with industry
groups and is the U.S. member of the International
Organization for Standardization (ISO) and the International
Electro technical Commission (IEC). Long-established
computer standards from ANSI include the American Standard
Code for Information Interchange (ASCII) and the Small
Computer System Interface (SCSI). In addition to DEC VT,
3270 and 5250, ANSI is a Terminal Emulation (TE) option on
some data collection computers.
Antenna - An antenna is
a specialized transducer that converts radio-frequency (RF)
fields into alternating current (AC) or vice-versa. In the
AIDC industry, a variety of antennas are used to modify or
focus the gain of signal strength and include
omni-directional, directional, high gain, and low or no gain
antennas.
AS400 - The AS/400,
formally renamed the "eServer iSeries/400," but still
commonly known as AS/400 - is a midrange server designed for
small businesses and departments in large enterprises and
now redesigned so that it will work well in distributed
networks with Web applications. The AS/400, one of IBM's
greatest success stories, is widely installed in large
enterprises at the department level, in small corporations,
in government agencies, and in almost every industry
segment.
Avalanche - Avalanche,
from Wavelink, is a software product that provides
centralized management of a large installed based of mobile
end devices. It provides over the air configuration changes
and and security among other things. See also Mobile Manager
from Wavelink.
Backbone - A backbone is
a larger transmission line that carries data gathered from
smaller lines that interconnect with it. At the local level,
a backbone is a line or set of lines that local area
networks (LAN) connect to for a wide area network (WAN)
connection or within a local area network to span distances
efficiently (for example, between buildings).
Bandwidth - Bandwidth
has a general meaning of how much information can be carried
in a given time period (usually a second) over a wired or
wireless communications link. For example, a link with a
broad bandwidth - that is, a broadband link - is one that
may be able to carry enough information to sustain the
succession of images in a video presentation. More
technically, bandwidth is the width of the range of
frequencies that an electronic signal occupies on a given
transmission medium. Any digital or analog signal has a
bandwidth. In digital systems, bandwidth is expressed as
bits (of data) per second (bps) or Kbps or Mbps.
Bar code - A bar code is
the image of lines (bars) and spaces that is affixed to
retail store items, identification cards, products,
documents, postal mail, etc. to identify a particular
product number, person, or
location. The code uses a sequence of bars and spaces to
represent numbers and other symbols, known as a symbology.
Batch - Batch refers to
a way that automatic data collection computers operate.
Batch devices do not have a wired or wireless real-time
connection to a host machine or application. They run a
software
application that prompts the user for data. Data is
collected and stored in memory or in a data file. At the end
of the day or the user’s shift, the device is placed in a
dock, cradle or otherwise connected to a PC or other host
machine and the stored data is then downloaded to the host.
Bridge - In networking,
a bridge extends the maximum distance of your network by
connecting network segments which can be of dissimilar
types. For example, RF to Ethernet. Access Points are
bridges. Bridges determine the physical (MAC) address of the
destination of a packet and will then rebroadcast the signal
only if it resides on the other segment, thereby reducing
overall
CAT 5 - CAT5 is one of
the many categories of unshielded twisted pair (UTP) cables.
The specifications describe the cable material as well as
the types of connectors and junction blocks to be used in
order
to conform to a category. CAT5 cables support up to 100Mbps
transmission speeds over a distance of 100 meters.
CardBus - CardBus is the
trade name for an advanced PC Card (also known as PCMCIA
card) specification. The technology is used primarily in
notebook and portable computers. The CardBus card fits in a
slot like a conventional PC card. CardBus allows for all the
functions that are possible with PC cards, but with several
improvements.
CE - Windows CE is an
operating system from Microsoft designed for hand held
computers. The CE operating system and the subset PocketPC
operating system are designed for ¼ size VGA screens. CE has
a Graphical User Interface (GUI) and is designed for
application use in the business environment.
Compact Flash (CF) - A
CompactFlash (CF) card is a popular memory card developed by
SanDisk in 1994 that uses flash memory to store data on a
very small card. A CompactFlash card makes data easy to add
to a wide variety of computing devices, including digital
cameras and music players, desktop computers, personal
digital assistants (PDAs), digital audio recorders, and
photo printers. Based on the
Cisco - Founded in 1984 by a group of computer scientists
from Stanford University, Cisco has grown into the leading
manufacturer of wired and wireless network equipment used on
the Internet and on private networks worldwide.
Client - A client is the
requesting program or user in a client/server relationship.
For example, the user of a Web browser is effectively making
client requests for pages from servers all over the Web. The
browser itself is a client in its relationship with the
computer that is getting and returning the requested HTML
file. The computer handling the request and sending back the
HTML file is a server. Other examples of clients are email
such as Outlook, Terminal Emulation (TE) and custom software
applications on a data collection computer that communicate
with a server application in real-time.
Client/Server -
Client/server describes the relationship between two
computer programs in which one program, the client, makes a
service request from another program, the server, which
fulfills the request. In a network, the client/server model
provides a convenient way to interconnect programs that are
distributed efficiently across different locations. Examples
of client/server include - Outlook running on your PC and
our Ryzex email server,
Coaxial Cable - Coaxial
cable is called "coaxial" because it includes one physical
channel that carries the signal surrounded (after a layer of
insulation) by another concentric physical channel, both
running along the same axis. The outer channel serves as a
ground. Many of these cables or pairs of coaxial tubes can
be placed in a single outer sheathing and, with repeaters,
can carry information for a great
distance.
Code 39 - The Code 39
symbology (also called "3 of 9“ and “the universal code”),
developed by Intermec, is probably the most commonly used
barcode, and it is a standard for many government bar code
specifications. This barcode encodes numbers, uppercase
letters, and some punctuation. The list of valid characters
for the Code 39 barcode includes:
Capital letters A to Z
Numbers 0 to 9
The space character
Symbols -. $ / +%
Code 128 - The Code 128
symbology is a variable length symbology which can encode
numeric, upper and lower case alphabetic characters (the
full 128 ASCII character set), punctuation, special function
and control data characters. It also enables numeric data to
be compressed into double the normal density by encoding two
digits per encoded character.
Code 128 has three different character sets, called subset
A, subset B, and subset C, which allow the bar code to be
optimized for size.
Characters Per Inch (cpi)
- For a given font or symbology, cpi (characters per inch)
is the number of typographic or data characters that will
fit in each inch of a printed line.
Barcode density is usually specified in cpi.
Direct Current (DC) -
Direct Current (DC) is the unidirectional flow or movement
of electric charge carriers, usually electron. The intensity
of the current can vary with time, but the general direction
of
movement stays the same at all times. As an adjective, the
term DC is used in reference to voltage whose polarity never
reverses. Most data collection equipment takes DC power. The
power supplies that are ordered with the equipment converts
AC power into the appropriate DC power level.
Decoded - Usually refers
to a decoded or decoding barcode scanner. In the old days,
scanners transmitted data called raw count data which is
simply a list of the amounts of time spent on each bar and
space in a barcode. It was then up to another device called
a reader or decoder to translate the raw count data into
something meaningful such as ASCII data. The decoder would
then transmit the data to a host computer. Today, we have
scanners that decode the raw count data into ASCII or
Keycode data and transmit it straight to the host computer.
Density - Usually refers
to the density of a barcode. Barcodes printed with a small X
Dimension are more dense than those printed with a large X
Dimension because more information can be crammed into a
given space. Density is usually expressed in mils.
Depth of Field - Depth
of Field (DOF) is the difference between the farthest
scannable distance and the closest scannable distance to the
barcode.
Dynamic Host Configuration Protocol
(DHCP) -DHCP is a communications protocol that
lets network administrators manage centrally and automate
the assignment of Internet Protocol (IP) addresses in an
organization's network. Each machine that can connect to the
Internet needs a unique IP address. When an organization
sets up its computer users with a connection to the network,
an IP address must be assigned to each machine manually
without DHCP. With DHCP, the IP addresses may be assigned to
each computer automatically. DHCP lets a network
administrator supervise and distribute IP addresses from a
central point.
Dual Inline Package (DIP)
- A DIP is a common type used to mount and enclose
semi-conductor chips. See also DIP Switch.
Dipole Antenna - Unlike
an isotropic antenna, a dipole antenna is a real antenna
that has a 360° radiation pattern in the horizontal plane
and a 75° radiation pattern in the vertical plane if the
antenna is mounted vertically. This creates a doughnut
shaped radiation pattern. Because the beam is slightly
concentrated, dipole antennas have a gain over isotropic
antennas of 2.14dbi in comparison to an isotropic antenna.
Some antennas are rated in comparison to a dipole antenna
which is denoted by dBd. So, dipole antennas have a gain of
0dBd in relation to itself which is equivalent to 2.14dBi. A
half wave dipole antenna (.5dBd) is rated at 1dBi. A quarter
wave dipole antenna (.25dBd) is rated at .5dBi).
back to
top
Dip Switch - A series of
tiny switches built into circuit boards. The housing for the
switches, which has the same shape as a chip, is the DIP.
DIP switches enable you to configure a circuit board for a
particular type of computer or application. The installation
instructions should tell you how to set the switches. DIP
switches are always toggle switches, which means they have
two possible positions -- on or off. (Instead of on and off,
you may see the numbers 1 and 0.)
Many data collection devices, especially legacy, such as
printers and radios have DIP switches. These switches are
set for certain conditions, this is how these devices were
configured.
Direct Sequence - DS
Spread Spectrum is a RF technology that uses one to three
22MHz wide channels. Typically only one channel is used at a
time. Other channels can be used when interference is an
issue. DSSS provides a larger range and throughput than
FHSS. DSSS is typically more costly than FHSS. DSS is more
susceptible to interference than FHSS.
Direct Thermal - Direct
thermal printing utilizes a heat sensitive chemically coated
paper. The thermal print head is typically a long linear
array of tiny resistive heating elements (about 100 to 300
per inch) that are arranged perpendicular to the paper flow.
Each thermal print head element locally heats an area on the
chemically coated paper directly under the print element.
This induces a chemical reaction, which causes a black dot
to form in that area. Building it from dot rows as the media
passes underneath the active edge of the print head forms
the image.
Directional Antenna -
Directional antennas focuses the radiation pattern in a
specific direction. They are available in a variety of from
factors and strengths. Directional antennas are useful in
covering long hallways and in bridging two wireless networks
together.
Diversity Antenna - The
use of diversity antennas is the use of two identical
antennas for a single radio in an access pointOne antenna is
the primary and the other is the secondary. The access point
will periodically check the signal strength from each
antenna and will use the stronger one. Diversity antennas
are intended to be used as a last resort to reduce
multipathing. They should not be used as a default.
Diversity theory dictates that identical antennas be used
and that they be mounted very precise distances apart.
Dots Per Inch (dpi) - In
printing, dpi is the usual measure of printed image quality
on the paper. The average printer today provides 152 dpi or
607 dpi. Choosing the higher print quality usually reduces
the speed of printing each
page.
Electrically Earasable Programmable
Read Only Membory (EEPROM) - EEPROM, pronounced
double-ee-prom or e-e-prom, is user-modifiable read-only
memory (ROM) that can be erased and reprogrammed (written
to) repeatedly through the application of higher than normal
electrical voltage. Unlike EPROM chips, EEPROMs do not need
to be removed from the computer to be modified. However, an
EEPROM chip has to be erased and reprogrammed in its
entirety, not selectively. It also has a limited life - that
is, the number of times it can be reprogrammed is limited to
tens or hundreds of thousands of times. In an EEPROM that is
frequently reprogrammed while the computer is in use, the
life of the EEPROM can be an important design consideration.
A special form of EEPROM is flash memory, which uses normal
PC voltages for erasure and reprogramming.
Electro Magnetic Interference (EMI)
- EMI is the disruption of operation of an
electronic device when it is in the vicinity of an
electromagnetic field in the radio frequency (RF) spectrum
that is caused by another electronic device. The internal
circuits of personal computers and heavy machinery can
generate EM fields in the RF range over a wide band of
frequencies. These emissions can interfere with the
performance of sensitive wireless receivers nearby.
End of Life (EOL) -
After a product has been on the market for a significant
period of time, usually four years or more, the manufacturer
will designate the product as end of life and will no longer
be sold. This can happen because there is no demand for the
product or because parts to build the product can no longer
be sourced, or because a product that supercedes it is
available.
Usually, the manufacturer will still provide support and
service on the product for a few months after EOL.
Eventually though, the product will be designated End Of
Service and End Of Support.
back to top
Erasable Programmable Read Only
Memory (EPROM) - EPROM is programmable read-only
memory (programmable ROM) that can be erased and re-used.
Erasure is caused by shining an intense ultraviolet light
through a window that is designed into the memory chip.
(Although ordinary room lighting does not contain enough
ultraviolet light to cause erasure, bright sunlight can
cause erasure. For this reason, the window is usually
covered with a label when not installed in the computer.) A
different approach to a modifiable ROM is electrically
erasable programmable read only memory (EEPROM).
Electro Static Discharge (ESD)
- Electrostatic discharge is the release of static
electricity when two objects come into contact. Familiar
examples of ESD include the shock we receive when we walk
across a carpet and touch a metal doorknob and the static
electricity we feel after drying clothes in a clothes dryer.
A more extreme example of ESD is a lightening bolt. While
most ESD events are harmless, it can be an expensive problem
in many industrial and manufacturing environments. If not
properly grounded, ESD can cause serious damage to
electronic equipment.
Extended Service Set ID (ESSID)
- A Service Set Identifier (SSID) is a sequence of
characters that uniquely names a Wireless Local Area Network
(WLAN). This name allows stations to connect to the desired
network when multiple independent networks operate in the
same physical area. Each set of wireless devices
communicating directly with each other is called a Basic
Service Set (BSS). Several BSSs can be joined together to
form one logical WLAN segment, referred to as an extended
service set (ESS). A Service Set Identifier (SSID) is simply
the 1-32 byte alphanumeric name given to each ESS.
Ethernet - Ethernet is
the most widely-installed local area network (LAN)
technology. Specified in the 802.3 standard from the IEEE,
Ethernet was originally developed by Xerox and then
developed further by Xerox, DEC, and Intel. An Ethernet LAN
typically uses coaxial cable or special grades of twisted
pair wires. Ethernet is also used in wireless LANs. The most
commonly installed Ethernet systems are called 10BASE-T and
provides transmission speeds up to 10Mbps. Devices are
connected to the cable and compete for access using a
Carrier Sense Multiple Access with Collision Detection
(CSMA/CD) media access method. Fast Ethernet or 100BASE-T
provides transmission speeds up to 100Mbps and is typically
used for LAN backbone systems, supporting workstations with
10BASE-T network interface cards (NIC). Gigabit Ethernet
provides an even higher level of backbone support at
1000Mbps (1Gbps or 1 billion bits per second). 10-Gigabit
Ethernet provides speeds up to 10 billion bits per second.
Fiber Optic - Fiber
optic (or "optical fiber") refers to the medium and the
technology associated with the transmission of information
as light impulses along a glass or plastic wire or fiber.
Fiber optic wire carries much more information than
conventional copper wire such as 10BASE-5, 10BASE-2,
10BASE-T, or 100BASE-T and is far less subject to
electromagnetic interference. Most telephone company
long-distance lines are now fiber optic.Transmission on
fiber optic wire requires repeating at distance intervals.
The glass fiber requires more protection within an outer
cable than copper and fiber is more expensive than copper.
FDDI and 10BASE-F use fiber optic cable.
Firmware - Firmware is
software that is inserted into programmable read-only memory
(PROM), thus becoming a permanent part of a computing
device. Firmware is created and tested like software using
processor emulators. When ready, it can be distributed like
other software and, using a special user interface,
installed in the programmable read-only memory by the user.
Most data collection scanners, readers, printers, network
devices and other devices have firmware.
Flash - Flash memory
(sometimes called "flash RAM") is a type of
constantly-powered nonvolatile memory that can be erased and
reprogrammed in units of memory called blocks. It is a
variation of
electrically erasable programmable read-only memory
(EEPROM). Flash memory is not very useful as RAM because of
the overhead involved in writing data to a flash memory
device. Flash memory tends to much less expensive than SRAM.
Flash memory is available in a PC Card format. The term
flash is also used as a verb to describe the act of burning
or loading firmware onto a data collection computer,
scanner, printer, network device.
Frequency Hopping - FH
Spread Spectrum is a RF technology that uses up to 79 1MHz
wide channels. Each “channel” is actually a preset sequence
of frequencies. Transmissions will run the sequence for a
given channel, in other words, it hops from one frequency to
another during transmission. It can stay on a given channel
for up to 400ms before hopping. As a result, this technology
is more immune to interference than DSSS. Intermec’s devices
with Open Air radios and Symbol’s Spring and 802.11 radios
use Frequency Hopping.
back to top
Gateway - A gateway is a
network point that acts as an entrance to another network. A
gateway is a router that also performs protocol
translations.On the Internet, a node or stopping point can
be either a gateway node or a host (end-point) node. Both
the computers of Internet users and the computers that serve
pages to users are host nodes. The computers that control
traffic within your company's network or at your local
Internet service provider (ISP) are gateway nodes.
General Packet Radio Services
(GPRS) - GPRS is a packet-based wireless
communication service that promises data rates from 56 up to
114 Kbps and continuous connection to the Internet for
mobile phone and computer users. The higher data rates will
allow users to take part in video conferences and interact
with multimedia Web sites and similar applications using
mobile handheld devices as well as notebook computers. GPRS
is based on Global System for Mobile (GSM) communication and
will complement existing services such as circuit-switched
cellular phone connections and the Short Message Service
(SMS). Some data collection computers are available with
GPRS radios.
Global System for Mobile
communications (GSM) - GSM is a digital mobile
telephone system that is widely used in Europe and other
parts of the world. GSM uses a variation of time division
multiple access (TDMA) and is the most widely used of the
three digital wireless telephone technologies (TDMA, GSM,
and CDMA). GSM digitizes and compresses data, then sends it
down a channel with two other streams of user data, each in
its own time slot. It operates at either the 900 MHz or 1800
MHz frequency band.
Hertz - Hertz is a unit
of frequency (of change in state or cycle in a sound wave,
alternating current, or other cyclical waveform) of one
cycle per second. It replaces the earlier term of "cycle per
second (cps)." For example, in the United States, common
house electrical supply is at 60 hertz (meaning the current
changes direction or polarity 120 times, or 60 cycles, a
second). (In Europe, line frequency is 50 hertz, or 50
cycles per second.) Broadcast transmission is at much higher
frequency rates, usually expressed in kilohertz (KHz) or
megahertz (MHz).
Infrared Data Association (IrDA)
- IrDA is an industry-sponsored organization set up in 1993
to create international standards for the hardware and
software used in infrared communication links. In this
special form of RF transmission, a focused ray of light in
the infrared frequency spectrum, measured in terahertz, or
trillions of hertz (cycles per second), is modulated with
information and sent from a transmitter to a receiver over a
relatively short distance. Infrared radiation (IR) is the
same technology used to control a TV set with a remote
control. Infrared data communication is playing an important
role in wireless data communication due to the popularity of
laptop computers, personal digital assistants (PDAs),
digital cameras, mobile telephones, pagers, and other
devices.
Intellitrack -
Intellitrack started off as a PSC product and then broke
away to form their own company. IntelliTrack® WMS is a low
end and fairly easy-to-use warehouse management solution
available in both batch and real-time RF versions.
IntelliTrack WMS includes advanced warehouse management
capabilities, including directed picking and put-away,
cubing, wave management, and cross docking. Intellitrack’
Data Management Software provides modular solutions for:
Inventory, Stock Room, Fixed Assets, Check in / Check out.
Interleaved 2 of 5 (I 2 of 5)
- Interleaved 2 of 5 is a barcode symbology that is used for
many applications and is also referred to as USS ITF 2/5,
ITF and I 2of 5 (pronounced Eye 2 of 5). It is a
high-density numeric barcode type that can only encode 0 -
9. It is based on 2 of 5 but also encodes information in the
spaces.
Intermec (Interface Mechanism)
- Intermec designs, manufactures and sells data collection
equipment such as scanners, readers/decoders, barcode
printers, print media, wireless network systems, and other
network devices. In 1988, Intermec bought Norand, a
competitor.
Input/Output (I/O) - I/O
is a very old term for Input/Output. Originally, it was used
in programming and digital circuit design to refer to
functions or circuits that dealt specifically with input
and/or output functionality of hardware or software. Over
the years, it has developed other meanings and it is a
rarely used term today.
Internet Protocol (IP) -
The Internet Protocol (IP) is the method or protocol by
which data is sent from one computer to another on a
network. Each computer (known as a host) on the network has
at least one IP address that uniquely identifies it from all
other computers on the network. When you send or receive
data (for example, an e-mail note or a Web page), the
message gets divided into little chunks called packets. Each
of these packets contains both the sender's Internet address
and the receiver's address as well as the data.
IP Address - In the most
widely installed level of the Internet Protocol (IP) today,
an IP address is a 32-bit number that identifies each sender
or receiver of information that is sent in packets across
the Internet or a network. Unlike a MAC address, an IP
address is a logical address and is assigned to a computer,
printer or other device on a network either manually or
automatically by a DHCP server. 192.168.220.19 is an example
of an IP address. It is presented in four octets, each of
which is 8 bits comprising a decimal number from 0 to 255.
An IP address has two parts – the network address and the
host address. The network is the first X number of bits
(varies depending on the network) and the host address is
the remaining bits. Subnet masks determine how much of the
IP address is network address and how much is host address.
Local Area Network (LAN)
- A LAN is a group of computers and associated
devices that share a common communications line or wireless
link and typically share the resources of a single processor
or server within a small geographic area, for example,
within an office building.
Laser (Light Amplification by
Stimulated Emission of Radiation) - A laser is a
device containing a substance where the majority of its
atoms or molecules are put into an excited energy state. As
a result, the laser emits coherent light of a precise
wavelength in a narrow beam. Many barcode scanners use laser
light.
LEAP (Lightweight Extensible
Authentication Protocol) - LEAP is the
lightweight version of EAP and is a Cisco proprietary
protocol also known as Cisco-Wireless EAP. LEAP provides
username/password-based authentication between a wireless
client and a RADIUS server like Cisco ACS or Interlink AAA.
LEAP is one of several protocols used with the IEEE 802.1x
standard for LAN port access control. In the 802.1x
framework, a LAN station cannot pass traffic through an
Ethernet hub or WLAN access point until it successfully
authenticates itself. The station must identify itself and
prove that it is an authorized user before it is actually
allowed to use the LAN. The primary difference between LEAP
and EAP/TLS is that LEAP uses a username and password to
authenticate while EAP/TLS uses
digital certificates.
LED (Light Emitting Diode)
-A light-emitting diode (LED) is a semiconductor device that
emits visible light when an electric current passes through
it. The light is not particularly bright, but in most LEDs
it is monochromatic, occurring at a single wavelength. The
output from an LED can range from red (at a wavelength of
approximately 700 nanometers) to blue-violet (about 400
nanometers). Some LEDs emit infrared (IR) energy (830
nanometers or longer); such a device is known as an
infrared-emitting diode (IRED).Wand, CCD and imaging
scanners use LEDs for a light source.
Lithium Ion (Li-Ion) -A
Lithium Ion battery is a rechargeable battery with twice the
energy capacity of a NiCd battery and greater stability and
safety. It is much less susceptible to memory effect than
NiCd and NiMH batteries.
MilliAmpere Hour (mAh) -
A milliampere hour is 1000th of an ampere hour (Ah). Both
measures are commonly used to describe the energy charge
that a battery will hold and how long a device will run
before the battery needs recharging. Many batteries used for
portable data collection computers use 1500mAh to 2700mAh
batteries.
Mil - An international
unit of measurement equaling one thousandth of an inch.
Barcodes are measured using mils. Mil comes from the French
word mille meaning thousand.
Mobile Manager - Mobile
Manager, from Wavelink, is a multi-vendor solution for
providing effective network management and control over
wireless LANs. Mobile Manager will rapidly configure and
deploy wireless networks (access points), maintain network
health and performance, perform updates to mobile devices,
and manage remote sites. This product is similar to but more
robust than Intermec’s MobileLAN Manager.
back to top
MobileLAN Manager -
MobileLAN Manager, from Intermec, is a wireless network
management software package that manages Intermec access
points. It is a Java application, so it is a stand alone
application (previous incarnations of this type of product
from Intermec such as IncaView required that HP OpenView be
owned and installed by the customer. This product is similar
in nature to Mobile Manager from Wavelink, however it is not
as robust as the Mobile Manager product
Milliwatt (mW) - The
watt (abbreviated W) is the standard unit of power (or
energy per unit time) and is the equivalent of one joule per
second. The watt is used to specify the rate at which
electrical energy is dissipated, or the rate at which
electromagnetic energy is radiated, absorbed, or
dissipated.mW or milliwatt is one thousandth of a Watt.In AC
and DC electrical cicuits, W and mW is used to specify
wattage.In RF, W and mW is also used to express output
power.
Narrowband - Generally,
narrowband describes telecommunication that carries voice
information in a narrow band of frequencies. More
specifically, the term has been used to describe a specific
frequency range set aside by the U.S. FCC for mobile or
radio services, typically in the 400Mhz range. In the AIDC
industry Narrow Band communications refer to Ultra High
Frequency (UHF) RF.
Network Interface Card (NIC)
- Each device (Node) on a network will have a NIC. The NIC
is installed inside the device and serves as the interface
to the network. The NIC can be Ethernet, Token Ring, RF, or
other. It provides a real-time dedicated connection to the
network.Every NIC in the world has a unique hardware address
called a MAC (Media Access Control) address. This is not to
be confused with an IP address which is a logical address
assigned to the NIC on each computer, printer, router, and
other devices on a local area network (LAN). Nodes may have
more than one NIC installed to talk to different networks.
Nicket Cadium (NiCd) -
The NiCad battery is a type of battery commonly used in
portable computers, camcorders, portable drills, hand held
data collection computers, and other small battery-powered
devices, having an effective and even power discharge. When
compared to Nickel-Metal Hydride (NiMH) and Lithium Ion
batteries (Li-ION), NiCd batteries are the most susceptible
to memory effect.
Nickel Metal Hydride (NiNH)
- The Nickel-Metal Hydride battery is a rechargeable power
source that is increasingly used in portable computers and
other devices. The NiMH battery provides up to 40 percent
longer service life than Nickel-Cadmium (NiCd) batteries as
well as greater charge capacity. NiMH batteries are also
used in cellular phones and camcorders. NiMH batteries are
less susceptible to memory effect than NiCd batteries but
more susceptible than Lithium Ion (Li-ION) batteries.
Node - In a network, a
node is a connection point, either a redistribution point or
an end point for data transmissions. In general, a node has
programmed or engineered capability to recognize and process
or forward transmissions to other nodes.In an offshoot
meaning, computers, printers, and other devices connected to
a network are also referred to as nodes.
Original Equipment Manufacturer
(OEM) - Originally, an OEM was a company that
supplied equipment to other companies to resell or
incorporate into another product using the reseller’s brand
name. For example, a maker of barcode scanners like HHP
might sell its scanners to a retailer like Intermec under a
brand name owned by Intermec. A number of companies, both
equipment suppliers and equipment resellers, still use this
meaning.More recently, OEM is used to refer to the company
that acquires a product or component and reuses or
incorporates it into a new product with its own brand name.
Omni-directional Antenna
- There are several types of antennas that are used in an RF
implementation. Omni-directional antennas are among them.
Omni-directional antennas radiate an RF signal in a 360
degree pattern.
Open Air - The Wireless
LAN Interoperability Forum (WLIF) was a consortium of
companies including Casio, Data General, Fujitsu, HP, IBM,
Intermec, Mitsubishi, Motorola, and Proxim, and was created
in May 1996 to develop an open interoperability
specification for wireless LAN devices. The result is the
standard called Open Air. Open Air is based on a radio from
Proxim, and uses Frequency Hopping and has a fixed data rate
of 1.6Mbps. Intermec, Telxon and LXE products used Open Air
radios. It is important to note that the Open Air standard
has nothing whatsoever to do with the 802.11 specifications
from the IEEE.
Packet -A packet is the
unit of data that is routed between an origin and a
destination on any packet-switched network such as Ethernet.
When any file (e-mail message, HTML file, Graphics
Interchange Format (GIF) file, Uniform Resource Locator
(URL) request, and so forth) is sent from one place to
another on the network, TCP/IP divides the file into
"chunks" of an efficient size for routing. Each of these
packets is separately numbered and includes the IP address
of source and the destination. The individual packets for a
given file may travel different routes through the network
to the destination. When they have all arrived, they are
reassembled into the original file (by TCP/IP at the
receiving end).
PC Card -A PC Card
(previously known as a PCMCIA card) is a credit card-size
memory or I/O device that fits into a personal computer,
usually a notebook or laptop computer. Probably the most
common use of a PC Card is the telecommunications modem and
network adaptor for notebook computers. The PC Card is based
on standards published by the Personal Computer Memory Card
International Association (PCMCIA). The PCMCIA 2.1 Standard
was published in 1993. As a result, PC users can be assured
of standard attachments for any peripheral device that
follows the standard. A PC Card has a 68-pin connector that
connects into a slot in the PC. There are three sizes (or
"types") of PC Cards based on the thickness of the cards:The
Type I and II cards work in a Type III slot and a Type I
card will work in a Type II slot. (On the other hand, the
thicker cards can't be fitted into the slots for the thinner
cards.)
PCMCIA (Personal
Computer Memory Card International Association) - The PCMCIA
is an industry group organized in 1989 to promote standards
for a credit card-size memory or I/O device that would fit
into a personal computer, usually a notebook or laptop
computer. The PCMCIA 2.1 Standard was published in 1993. As
a result, PC users can be assured of standard attachments
for any peripheral device that follows the standard. The
initial standard and its subsequent releases describe a
standard product, the PC Card.
Platform - In computers,
platform is a general term that refers to the physical
hardware machine or the operating system running on that
machine or the language and compiler that an application was
developed under or any combination of these. For example, my
customer’s platform is Unix running on a DEC machine. Or, my
application is written in C with the MS Visual C version
1.52 compiler. Or, my platform is an IBM AS400.
PocketPC - Windows
PocketPC is an operating system from Microsoft designed for
hand held computers. The PocketPC operating system and the
superset CE 3.0 operating system are designed for ¼ size VGA
screens such as are found on PDAs. PocketPC has a Graphical
User Interface (GUI) and is designed for consumer use. It
comes with applications such as Pocket Word, Pocket Excel,
Pocket Outlook, etc.
back to top
Power Over Ethernet (PoE)
- In the old days, when installing access points, the
customer or installer had to run data cabling such as UTP
and electrical cable to power access points. UTP cable has
four pairs of wires, only two pairs are used to carry data.
A few years ago, someone thought to carry power to the
access points through the one of the other pairs of wires in
the data cable, thereby eliminating the need for installing
electrical cable which can be quite expensive. Power Over
Ethernet involves the use of a power injector (Intermec
calls it a power bridge). The power injector is installed in
the central hub or switch room and is powered by AC power.
The data cable is run into the injector which adds power to
one of the unused wire pairs. DC power is then carried on
the data cable to the access point.
Point of Sale (POS) - A
point of sale is any checkout counter in a retail or
wholesale outlet. Much more complex than the cash registers
of even just a few years ago, the POS system can include the
ability to scan barcodes, record and track customer orders,
process credit and debit cards, connect to other systems in
a network, and manage inventory.Generally, a POS terminal
has as its core a personal computer, which is provided with
application-specific programs and I/O devices for the
particular environment in which it will serve.
Power Injector - A power
injector is a device that delivers DC power over a network
cable such as CAT5 UTP cable. This process is known as Power
Over Ethernet (PoE). Intermec calls their power injector the
MobileLAN Power Bridge. Symbol calls theirs the BIAS-T.
Cisco calls theirs a power injector. The use of a power
injector can eliminate the need to run AC power to each
access point location, thereby greatly reducing the cost of
an RF implementation.
Programmable Read Only Memory
(PROM) - Programmable read-only memory (PROM) is
read-only memory (ROM) that can be modified once by a user.
PROM is a way of allowing a user to tailor firmware using a
special machine called a PROM programmer. This machine
supplies an electrical current to specific cells in the ROM
that effectively blows a fuse in them. The process is known
as burning the PROM. Other forms of ROM are Erasable
Programmable Read-Only Memory (EPROM) or electrically
erasable programmable read-only memory (EEPROM).
Protocol - A protocol is
a set of rules governing a communication event in serial,
parallel, network, wireless and other forms of electronic
communication.Protocols exist at several levels in a
telecommunication connection. There are hardware protocols,
protocols between each of several functional layers of a
network protocol stack and high level software application
protocols and others.Both end points of a communication must
recognize and observe a protocol. Protocols are often
described in an industry or international standard.
PSC (Photographic Sciences
Corporation) - A manufacturer that makes barcode
scanners and data collection computers and terminals.
Programmers Software Kit (PSK)
- A PSK is a library of functions that a programmer uses to
develop an application for a data collection computer.
Intermec has a PSK for its Janus family of products and a
PSK for their Antares family of products. Other
manufacturers have libraries available as well for their
products. Sometimes its called a Software Developer’s Kit
(SDK).
Resolution - In
barcodes, resolution usually refers to how many data
characters can be printed in a given amount of space.
Resolution is usually specified in characters per inch
(cpi).
Retro Reflective - Retro
reflective labels have a shinny background surface. This
type of label stock is often used when a long scanning
distance is required. Combined with a large X Dimension and
a long range scanner, retro reflective labels can be scanned
from 50+ feet.
Radio Frequency (RF) -
Radio frequency is a term that refers to alternating current
(AC) having characteristics such that, if the current is
input to an antenna, an electromagnetic (EM) field is
generated suitable for wireless broadcasting and/or
communications. These frequencies cover a significant
portion of the electromagnetic radiation spectrum, extending
from nine kilohertz (9KHz), the lowest allocated wireless
communications frequency to thousands of gigahertz (GHz).
When an RF current is supplied to an antenna, it gives rise
to an electromagnetic field that propagates through space.
This field is sometimes called an RF field; in less
technical jargon it is a "radio wave."AIDC industry products
use UHF (400+MHz), 900MHz and 2.4GHz RF equipment.
Radio Frequency Identification
(RFID) - RFID is a technology that incorporates
the use of electromagnetic or electrostatic coupling in the
RF portion of the electromagnetic spectrum to uniquely
identify an object, animal, or person. RFID is coming into
increasing use in industry as an alternative to the barcode.
The advantage of RFID is that it does not require direct
contact or line-of-sight scanning. An RFID system consists
of three components: an antenna and transceiver (often
combined into one reader) and a transponder (the tag). The
antenna uses RF waves to transmit a signal that activates
the transponder. When activated, the tag transmits data back
to the antenna. The data is used to notify a programmable
logic controller that an action should occur. The action
could be as simple as raising an access gate or as
complicated as interfacing with a database to carry out a
monetary transaction. Low-frequency RFID systems (30 KHz to
500 KHz) have short transmission ranges, generally less than
six feet. High-frequency RFID systems (850 MHz to 950 MHz
and 2.4 GHz to 2.5 GHz) offer longer transmission ranges
that exceed 90 feet. In general, the higher the frequency,
the more expensive the system.
Read Only Memory (ROM) -
ROM is "built-in" computer memory containing data that
normally can only be read, not written to. ROM contains the
programming that allows your computer to be "booted up" or
regenerated each time you turn it on. Unlike a computer's
random access memory (RAM), the data in ROM is not lost when
the computer power is turned off. The ROM is sustained by a
small long-life battery in your computer. Other forms of ROM
include PROM, EPROM and EEPROM.
Router - On a network, a
router is a device or, in some cases, software in a
computer, that determines the next network point to which a
packet should be forwarded toward its destination. The
router is connected to at least two networks and decides
which way to send each information packet based on its
current understanding of the state of the networks it is
connected to. A more intelligent for of a router is a
gateway.
back to top
Software Developer’s Kit (SDK)
- An SDK is a library of functions that a programmer uses to
develop an application for a data collection computer.
Symbol has an SDK for its family of products. Other
manufacturers such as Intermec have libraries available as
well for their products, they call it the Programmer’s
Software Kit (PSK).
Server - 1) In general,
a server is a computer program that provides services to
other computer programs, called clients, in the same or
other computers.
2) The computer that a server program runs in is also
frequently referred to as a server (though it may contain a
number of server and client programs).
3) In the client/server programming model, a server is a
program that awaits and fulfills requests from client
programs in the same or other computers. A given application
in a computer may function as a client with requests for
services from other programs and also as a server of
requests from other programs.
Spread Spectrum - Spread
spectrum is a form of wireless communications in which the
frequency of the transmitted signal is deliberately varied.
This results in a much greater bandwidth than the signal
would have if its frequency were not varied.Data collection
computers and access points use Spread Spectrum technology
such as Direct Sequence SS and Frequency Hopping SS.
Spring - Spring Protocol
refers to the first 2.4GHz radios offered by Symbol
Technologies. It was designed to the draft version of the
802.11 standard and is often referred to as pre-802.11.
Service Set Identifier (SSI)
- A Service Set Identifier (SSID) is a sequence of
characters that uniquely names a Wireless Local Area Network
(WLAN). This name allows stations to connect to the desired
network when multiple independent networks operate in the
same physical area. Each set of wireless devices
communicating directly with each other is called a Basic
Service Set (BSS). Several BSSs can be joined together to
form one logical WLAN segment, referred to as an Extended
Service Set (ESS). A Service Set Identifer (SSID) is simply
the 1-32 byte alphanumeric name given to each ESS.
Subnet Mask - Once a
packet has arrived at an organization's gateway or
connection point with its unique network address, it can be
routed within the organization's internal gateways using the
host address as well. The router knows which bits to look at
(and which not to look at) by looking at a subnet mask. A
mask is simply a screen of numbers that tells you which
numbers to look at underneath, specifically an IP address.
In a binary mask, a "1" over a number says "Look at the
number underneath"; a "0" says "Don't look." Using a mask
saves the router having to handle the entire 32 bit address;
it can simply look at the bits selected by the mask. With
this example subnet mask - 255.255.255.0, the network
address occupies 24 bits or the first three octets and the
host address occupies the last eight bits or the last octet.
The sender and the receiver should be using the same subnet
mask in order to interpret the IP address properly.
Switch - A switch is a
network device that provides a central point of connection
between media segments. Switches are very intelligent hubs.
Switches can perform intelligent path selection and minimize
the amount of network traffic and hides the traffic from
devices not involved in a dialog.
back to top
Symbol Technologies -
Symbol Technologies is a manufacturer of data collection
scanners, computers and wireless network systems.
Symbology - The term
barcode symbology can be thought of similarly to the way we
think of the many languages we speak all around the world.
There are many symbologies and they each have a vocabulary
(character set) and a grammar or set of rules governing how
we use the vocabulary. Some barcode symbologies are more
appropriate for certain applications than others. Some
symbologies encode only numbers 0 – 9, others encode numbers
and upper case letters while others encode all 128 ASCII
characters. One-dimensional (linear) symbologies have been
around for years. Two-dimensional symbologies consist of
stacked row symbologies and area symbologies.
Transmission Control
Protocol/Internet Protocol - TCP/IP (TCP/IP) is
the basic communication protocol of the Internet. It can
also be used as a communications protocol in a private
network.
Terminal Emulation (TE)
- TE is the act of emulating a dumb data terminal to
remotely access a host computer or mainframe. Typical
terminals emulated include the following models:
ANSI
IBM3270
IBM5250
DEC VT 100, 220, 320, and 460.
Thermal Transfer -
Thermal transfer printers use the same basic technology as
direct thermal printers, but with the elimination of
chemically-coated media material in favor of a
non-sensitized face stock and a special inked ribbon. A
durable, polyester ribbon film coated with a dry thermal
transfer ink is placed between the thermal print head and
label. The thermal print head is used to transcribe the ink
onto the label surface, where it cools and anchors to the
media surface. The polyester ribbon is then peeled away,
leaving behind a stable, passive image.
Advantages: High
contrast, crisp image bar code print quality with a durable,
long-life and archival image stability, maximum readability
and IR scan ability, high contrast text, graphic and bar
code print capability, and capability of printing on an
unlimited variety of media stock – except multi-form.
Disadvantages: Cannot
print on media without use of ribbon – resulting in higher
supply costs over direct thermal, single pass thermal
transfer ribbon can be wasteful if little is printed on it,
ink transfer ribbon is a poor candidate for re-cycling, and
to obtain optimum print quality in thermal transfer, the
ribbon and media substrate MUST be compatible - otherwise,
the heat from the print head could melt the ribbon onto the
label causing internal printer problems.
Token Ring - A Token
Ring network is a LAN in which all computers are connected
in a ring or star topology and a bit- or token-passing
scheme is used in order to prevent the collision of data
between two computers that want to send messages at the same
time. Token Ring was developed by IBM and is now specified
by the IEEE in 802.5. The IEEE 802.5 Token Ring technology
provides for data transfer rates of either 4 or 16Mbps.
Universal Access Point (UAP)
- UAP is an Intermec acronym referring to a family of access
point products.
back to top
User Datagram Protocol (UDP)
- UDP is a communications protocol that offers a limited
amount of service when messages are exchanged between
computers in a network that uses the Internet Protocol (IP).
UDP is an alternative to the Transmission Control Protocol
(TCP) and, together with IP, is sometimes referred to as UDP/IP.
Like TCP, UDP uses the Internet Protocol to actually get a
data unit (called a datagram) from one computer to another.
Unlike TCP, however, UDP does not have all of the overhead
such as error checking and transmission retries. As a
result, UDP is much faster than TCP but not as reliable.
Network applications that want to save processing time
because they have very small data units to exchange (and
therefore very little message reassembling to do) may prefer
UDP to TCP. The Trivial File Transfer Protocol (TFTP) uses
UDP instead of TCP.
Ultra High Frequency (UHF)
- The UHF range of the radio spectrum used in legacy data
collection computers is typically in the band extending from
400MHz to 450MHz. These radios are crystal based. These
crystals must be grown and on occasion re-aligned because
they have a tendency to drift.Its radio output power of 1w
to 2w yields an effective range of one to two miles. Because
of this, a site license is required from the FCC in order to
use UHF radios in a data collection application.The data
rate is about 19.2Kbps or less.
Undecoded - Undecoded
scanners collect raw count data and transmit it to some
other device, a decoder, that then converts the data and
into ASCII data.
Unix - Unix is an
operating system that originated at Bell Labs in 1969 as an
interactive time-sharing system. Ken Thompson and Dennis
Ritchie are considered the inventors of Unix. The name
(pronounced YEW-nihks) was a pun based on an earlier system,
Multics. In 1974, Unix became the first operating system
written in the C language. Unix has evolved as a kind of
large freeware product, with many extensions and new ideas
provided in a variety of versions of Unix by different
companies, universities, and individuals, such SCO Unix, Sun
Microsystems Unix, and Linux. Because Unix is not owned by
anyone, it became the first open or standard operating
system that could be improved or enhanced by anyone.
Universal Product Code (UPC)
- UPC is a barcode symbology that encodes numeric
data only. It is used primarily in the retail industry to
barcode products. There are two versions of UPC, UPC Version
A which is a 12 digit symbology and UPC Version E which is a
6 digit symbology.
Universal Serial Bus (USB)
- USB (Universal Serial Bus) is a plug-and-play interface
between a computer and add-on devices (such as audio
players, joysticks, keyboards, telephones, scanners,
printers, and barcode scanners). With USB, a new device can
be added to your computer without having to add an adapter
card or even having to turn the computer off. The USB
peripheral bus standard was developed by Compaq, IBM, DEC,
Intel, Microsoft, NEC, and Northern Telecom and the
technology is available without charge for all computer and
device vendors. USB supports a data speed of 12 megabits per
second. This speed will accommodate a wide range of devices,
including MPEG video devices, data gloves, and digitizers.
It is anticipated that USB will easily accommodate plug-in
telephones that use ISDN and digital PBX. Some barcode
scanners are available with a USB interface.
Unshielded Twisted Pair (UTP)
- UTP cable is used for analog and digital communications.
Flat gray UTP cable is used for phone lines and thicker UTP
cable of various colors is used for digital networking. UTP
cable has two to four pairs of wires, each pair is twisted
around each other. UTP has no metallic shielding around the
pairs. Category 5 or CAT5 cable is a popular cable used for
networking and has four pairs. This type of cable is used in
the IEEE 10BASE-T and 100BASE-T specifications for wired
Ethernet networks.
Value Added Reseller (VAR)
- A VAR is someone who adds some type of value like software
to new or refurbished hardware products and sells to an end
user, however they do not as a primary business buy and sell
refurbished hardware.
Vehicle Mounted Unit (VMU)
- A VMU or VMT is simply a data collection computer that
mounts to a forklift or other vehicle. It get its power from
the vehicle itself. Because of this and because these units
are usually bigger than hand held units, they sometimes have
full size screens, keyboards and operating systems such as
Windows or Linux.
Video Terminal (VT) - VT
is a family of terminals from DEC that includes the DEC
VT100, 220, and 320. VT is the most popular terminal
emulation type found on data collection computers.
Wide Area Network (WAN)
- A WAN is a geographically dispersed telecommunications
network, sometimes global in nature. The term distinguishes
a broader telecommunication structure from a local area
network (LAN) or a Metropolitan Area Network (MAN). A wide
area network may be privately owned or rented, but the term
usually connotes the inclusion of public (shared user)
networks.
Wand - A wand, aka Light
Pen, is a type of barcode scanner. Wands use a Light
Emitting Diode (LED) for a light source and they must have
contact with the barcode. The user manually swipes the wand
from one end of the barcode to the other.
Wand Emulation - A
barcode scanner that supports wand emulation first decodes a
scanned barcode and then converts it back to a generic form
of undecoded data. This is provided so that a decoded
scanner may be connected to a reader or decoder that expects
undecoded data as input.
Wavelink - A company
that designs and sells software for terminal emulation,
wireless network management, end device management and
application development.
Wired Equivalent Privacy (WEP)
- WEP is a data encryption standard, specified in the 802.11
standards from the IEEE, that is designed to provide a
wireless local area network (WLAN) with a level of security
and privacy comparable to what is usually expected of a
wired LAN. A wired local area network (LAN) is generally
protected by physical security mechanisms that are effective
for a controlled physical environment, but may be
ineffective for WLANs because radio waves are not
necessarily bound by the walls containing the network. WEP
sought to establish similar protection to that offered by
the wired network's physical security measures by encrypting
data transmitted over the WLAN. 40 bit WEP encryption is
specified in the 802.11 standards. Access Point Manufactures
went beyond that and offered 128 bit WEP encryption, however
this is not part of the 802.11 standards.Although WEP is
sufficient to protect data from most would be hackers, WEP
encryption is vulnerable to those with the know how and the
tools to break the encryption keys. Other methods such as
password protection, end-to-end encryption, virtual private
networks (VPNs), and authentication can be put in place to
ensure privacy.
Wireless - Wireless
generally refers to devices that communicate with other
devices without wires. Examples of wireless media include
RF, infrared, microwave, and satellite.
It is important to note that RF is wireless but wireless is
not necessarily RF.
Wireless Local Area Network (WLAN)
- Wireless generally refers to devices that communicate with
other devices without wires. Examples of wireless media
include RF, infrared, microwave, and satellite. It is
important to note that RF is wireless but wireless is not
necessarily RF.
Wi-Fi Protected Access (WPA)
- Wi-Fi Protected Access is a specification of standards
based, interoperable security enhancements that strongly
increase the level of data protection and access control for
existing and future LANs. Designed to run on existing
hardware as a software upgrade, WPA is derived from and will
be forward compatible with the 802.11i standard. When
properly installed, it will provide wireless LAN users with
a high level of assurance that their data will remain
protected and the only authorized network users can access
the network. The Wi-Fi Alliance plans to begin
interoperability certification testing on Wi-Fi products
starting February 2003.
Wireless Wide Area Network (WWAN)
- WWAN is a wireless WAN which typically uses CDMA, GPRS and
other cell phone technology radios.
X Dimension - In
barcoding, the X Dimension is the nominal width of the
narrow bar in a barcode. Every barcode has an X dimension.
The widths of wider bars and spaces are specified as a
multiple of the X Dimension. The X Dimension is used to
determine a barcode’s density. The smaller the X Dimension,
the higher the density.
Zebra - A company that
manufacturers and sells a wide range of barcode printers,
accessories and media supplies.
2.4GHz - 2.4GHz is a RF
frequency band commonly used in the data collection
industry. Most of the major manufacturers provide access
points and data collection computers with 2.4GHz radios.
Some are proprietary such as the Spring radios from Symbol
but most 2.4GHz radios conform to one of the following
standards.
Open Air
802.11
802.11b
802.11g
3270 - The 3270
Information Display System ( a dumb terminal), a product
from IBM, was, prior to the arrival of the PC, the way that
almost the entire corporate world interfaced with a
computer. When first
produced (the early 1970s), a 3270 display terminal was
considered a vast improvement over its predecessor, the
2260.
The terminal was a non-graphical (text only) monochrome
(black screen with green letters) display that buffered data
so that key strokes could be saved until the ENTER key was
pressed.
Today, the 3270 is emulated in most Terminal Emulation (TE)
software packages along with VT and 5250.
5GHz - Devices with 5GHz
radios operate primarily in the range extending from 5.15GHz
to 5.35GHz and 5.725GHz to 5.825GHz.
The effective range of 5GHz radios varies dramatically from
about 35 feet to about 1800 feet outdoors. No RF site
license is required.
The data rate also ranges dramatically from 6Mbps to 54mbps.
The 802.11a standard specifies a 5GHz radio.
5GHz is much faster than UHF and 900MHz but has an area of
coverage about equal to or smaller than 2.4GHz. It is also
less susceptible to RF interference than 2.4GHz.
5250 - The 5250
terminal, a product from IBM, was the primary interface to
the IBM AS400. The terminal was a non-graphical (text only)
monochrome (black screen with green letters) display.
Today, the 5250 is emulated in most Terminal Emulation (TE)
software packages along with VT and 3270.
802 - The 802 specifications from the IEEE specify many
networking subjects as listed below.
802.1 - Internetworking
802.2 - Logical Link Control, defines the LLC & MAC
sublayers
802.3 - Ethernet (CSMA/CD)
802.4 - Token Bus LAN
802.5 - Token Ring LAN
802.6 - Metropolitan Area Network (MAN)
802.7 - Broadband Technical Advisory Group
802.8 - Fiber Optic Technical Advisory Group
802.9 - Integrated Voice and Data Networks
802.10 - Network Security
802.11 - Wireless Networks
802.12 - Demand Priority Access LAN, 100BaseVG-AnyLAN
802.15 - Wireless Personal Area Network (WPAN)
802.30 - 100Base T
802.1x - 802.1x is a
standard from the IEEE for passing EAP over a wired LAN. EAP
messages are packaged in Ethernet frames. It is
authentication and nothing more. 802.1x is also now used in
wireless LANs since the wireless standard 802.11i has not
yet been ratified. 802.1x has three components. The user or
client that wants to be authenticated is called a
supplicant. The actual server doing the authentication,
typically a RADIUS server, is called the authentication
server, and the device in between, such as an access point,
is called the authenticator. One of the key points of 802.1x
is that the authenticator can be simple and dumb - all of
the brains have to be in the supplicant and the
authentication server. This makes 802.1x ideal for access
points, which are typically small and have little memory and
processing power. The protocol in 802.1x is called EAP
encapsulation over LANs (EAPOL). It is currently defined for
Ethernet-like LANs including 802.11 wireless, as well as
token ring LANs such as Fiber Distributed Data Interface
(FDDI). Authentication algorithms in 802.1x include EAP
Cisco Wireless (LEAP), EAP-TLS and PEAP.
802.3 - 802.3 is a
standard for Ethernet, a method of physical communication in
a LAN, which is maintained by the IEEE. In general, 802.3
specifies the physical media and the working characteristics
of Ethernet. Ethernet supports these possible physical
media:
10BASE-2 (Thinnet coaxial cable with a maximum segment
length of 185 meters)
10BASE-5 (Thicknet coaxial cable with a maximum segment
length of 500 meters)
10BASE-F (fiber optic cable)
10BASE-T (twisted pair wire)
100BASE-T (twisted pair wire)
10BASE-36 (broadband multi-channel coaxial cable with a
maximum segment length of 3,600 meters)
802.3af - 802.3af, also
known as Power over Ethernet, defines a way to build
Ethernet power-sourcing equipment and powered terminals. The
specification involves delivering 48 volts of DC power over
unshielded twisted-pair (UTP) wiring. It works with existing
cable plant, including Category 3, 5, 5e or 6; horizontal
and patch cables; patch-panels; outlets; and connecting
hardware, without requiring modification. This approach of
delivering power to an access point utilizes a power
injector to add DC power to a CAT5 cable.
802.11 - 802.11 is a
wireless standard from the IEEE. The original standard
specifies three wireless technologies:
Infrared
Frequency Hopping
Direct Sequence
There have been additions to this standard that specify
faster technologies such as:
802.11b
802.11a
802.11g
There is also an addition that deals with wireless security.
802.11i
Often times, in the data collection industry, 802.11 refers
not only to the standard, but specifically to the 802.11
frequency hopping products from Symbol Technologies because
they are the only ones that released an 802.11 FH product.
802.11a - 802.11a is a
supplement standard to the 802.11 standard from the IEEE. It
specifies a 5GHz radio with data rates up to 54Mbps. It also
specifies fallback data rates with the lowest being 6Mbps.
At 6Mbps the range would be similar to the range of 802.11b
at 1Mbps.
802.11b - 802.11b is a
supplement to the 802.11 standard from the IEEE. It
specifies a Direct Sequence radio with a high end data rate
of 11Mbps. This standard also calls for fallback data rates
of 5.5, 2 and 1Mbps as distance from the access point
increases. Also specified in 802.11b is 40 bit WEP
encryption. Many manufacturers offered up to 128 bit WEP
encryption in their products, but this is not part of the
802.11b standard. Wi-Fi is sometimes thought to be
synonymous with 802.11b in error. Wi-Fi is a certification
applied to 802.11b products if they pass a compatibility
test. 802.11b is the first standard that has gained
world-wide acceptance and truly offers interoperability.
802.11g - Ratified in
June, 2003 as an IEEE standard for wireless local area
networks (WLANs), 802.11g offers wireless transmission rates
up to 54 megabits per second (Mbps) compared with the 11Mbps
per second of the 802.11b standard. Like 802.11b, 802.11g
operates in the 2.4 GHz range and is thus compatible with
it. 802.11g is not compatible with 802.11a.
802.11i - This draft
standard is a supplement to 802.11 and is intended to
improve WLAN security. It describes the encrypted
transmission of data between systems of 802.11a and 802.11b
WLANs. It defines new encryption key protocols including the
Temporal Key Integrity Protocol (TKIP) and the Advanced
Encryption Standard (AES). When this standard is ratified,
most likely in 2003, certain products may require hardware
upgrades to support it, but most products will only require
firmware upgrades.
900MHz - The 900Mhz
range of the radio spectrum used in legacy data collection
computers is typically in the band extending from 902MHz to
921MHz. 900MHz radios have an effective range of 3000 to
5000 feet outdoors. No RF site license is required. The data
rate is about 100 – 400Kbps. Each manufacturer's
implementation of a 900MHz radio system was completely
proprietary. 900MHz is much faster than UHF but has a
smaller area of coverage. It is also less susceptible to RF
interference than UHF.
|
