Motorola ET1 Integrator Manual page 139

Symbol Length. Length of symbol measured from the beginning of the quiet zone (margin) adjacent to the start
character to the end of the quiet zone (margin) adjacent to a stop character.
Symbology. The structural rules and conventions for representing data within a particular bar code type (e.g. UPC/EAN,
Code 39, PDF417, etc.).
T
TCP/IP. (Transmission Control Protocol/Internet Protocol) A communications protocol used to internetwork dissimilar
systems. This standard is the protocol of the Internet and has become the global standard for communications. TCP
provides transport functions, which ensures that the total amount of bytes sent is received correctly at the other end.
UDP is an alternate transport that does not guarantee delivery. It is widely used for real-time voice and video
transmissions where erroneous packets are not retransmitted. IP provides the routing mechanism. TCP/IP is a
routable protocol, which means that all messages contain not only the address of the destination station, but the
address of a destination network. This allows TCP/IP messages to be sent to multiple networks within an
organization or around the world, hence its use in the worldwide Internet. Every client and server in a TCP/IP
network requires an IP address, which is either permanently assigned or dynamically assigned at startup.
Telnet. A terminal emulation protocol commonly used on the Internet and TCP/IP-based networks. It allows a user at a
terminal or computer to log onto a remote device and run a program.
TFTP. (Trivial File Transfer Protocol) A version of the TCP/IP FTP (File Transfer Protocol) protocol that has no directory
or password capability. It is the protocol used for upgrading firmware, downloading software and remote booting of
diskless devices.
Tolerance. Allowable deviation from the nominal bar or space width.
Transmission Control Protocol/Internet Protocol. See TCP/IP.
Trivial File Transfer Protocol. See TFTP.
U
UDP. User Datagram Protocol. A protocol within the IP protocol suite that is used in place of TCP when a reliable
delivery is not required. For example, UDP is used for real-time audio and video traffic where lost packets are simply
ignored, because there is no time to retransmit. If UDP is used and a reliable delivery is required, packet sequence
checking and error notification must be written into the applications.
UPC. Universal Product Code. A relatively complex numeric symbology. Each character consists of two bars and two
spaces, each of which is any of four widths. The standard symbology for retail food packages in the United States.
Glossary - 7