COMSPHERE 3825Plus Modem
Glossary-4
November 1996
3825-A2-GB30-20
DTMF
Dual Tone Multi-Frequency. DTMF tones are the sounds produced by pressing the keys of a
Touch Tone phone, or by dialing a number with a modem using the ATDTn command.
EIA
Electronic Industries Association. This organization provides standards for the data
communications industry.
EIA-232-E
An Electronic Industries Association’s standard defining the 25-position interface between data
terminal equipment and data communications equipment.
EIA RS-366-A
An Electronic Industries Association’s standard defining the 25-position interface between data
terminal equipment and data communications automatic calling equipment.
EPROM
Erasable programmable read-only memory.
error control
An algorithm used to correct data transmission errors.
escape sequence
Default setting is +++. This sequence lets you switch your modem from Data mode to Command
mode.
extended result codes
An asynchronous message (in either numbers or words) that includes VF data rate and error
control information the modem sends to the DTE after executing or trying to execute a command.
fax modem
A modem capable of emulating some features of a fax machine. Working under the control of fax
software, a fax modem can communicate with a fax machine or with another fax modem.
fax software
A program or system of programs installed on a computer that allow a fax modem to send and
receive facsimile images.
FCC
Federal Communications Commission. Board of Commissioners that regulates all interstate and
foreign electrical communication systems that originate from the United States.
full-duplex
Simultaneous, two-way communications.
Group III
A fax standard that specifies a rate of transmission of about one page per minute.
half-duplex
Two-way data communications allowed in only one direction at a time.
handshaking
The exchange of predetermined codes and signals (tones) to establish a connection between two
modems.
HDLC
High-level Data Link Control. A communications protocol defined by ISO.
host
A computer attached to a network that shares its information and devices with the rest of the
network.
Hz
A unit of frequency (hertz) that equals one cycle per second.
ISO
International Organization for Standardization.
ITU-T
The Telecommunications Standardization Sector of the International Telecommunications Union,
an advisory committee established by the United Nations to recommend communications
standards and policies. Before March 1993 it was called CCITT.
JM8
A jack used for leased-line networks. Pins 1 and 2 are the transmit pair and Pins 7 and 8 are the
receive pair.
LCD
Liquid Crystal Display. The device that permits text to be displayed on the DCP.
