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Motorola 326X V.34 User Manual

Page 229

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Glossary-3

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DTMF

Dual Tone Multi-Frequency. A signaling method used for push-button telephones that
combines two output signals to create a unique tone for each of the 12 keys.

EBCDIC

Extended Binary Coded Decimal Interchange Code. A method of coding digital signals
using eight bits to generate 256 different characters.

Echo

Reflection back to the sender of a transmitted signal (as heard on telephone circuits
involving long distances, or poor transmission facilities).

EIA

Electronic Industries Association. The American electronics standards group.

EIA/TIA 232-D

The most commonly used computer/modem interface. An electrical standard for
interconnecting data communications equipment (DCE) and data terminal equipment (DTE)
established by EIA. (The pinout is the same as for EIA 232-C and is nearly equivalent to
ITU V.24.)

EOT

End-of-transmission control character in character-oriented protocols (applied to BISYNC).
Tells the receiver that all user data (text) has been sent.

ETX

End-of-text control character. Tells the receiver that the end of a message has been reached.

Exclusion key
telephone

Allows calls to be answered manually and transferred to the modem using an integral
exclusion key.

Fallback

Switching the data system to a lower transmission speed either for reduced traffic during
off-peak hours or because of distortion in the telephone system.

Fall forward

Switching from a lower to a higher data rate.

Flow control

Controls data transfer between endpoints in a data network; line signals or flow control
characters stop and start the flow of data.

Four-wire

A circuit containing two pairs of wires, one pair for each transmission direction.

Full-duplex

A signaling circuit that allows simultaneous 2-way transmission and reception.

Frame

A group of bits transmitted serially over a communications channel. The basic data
transmission unit used with bit-oriented protocols.

Gain

The amount by which an amplifier (or power) increases the amplitude of a signal passing
through it; often represented in dB.

Half-duplex

A circuit that allows alternating transmit and receive signals, but not both simultaneously.

HDLC

High-level data link control. ITU-specified, bit-oriented, data-link control protocol; any
related control of data links by specified series of bits rather than by control characters.

Hexadecimal

Base 16 number system with digits ranging from 0 to F.

ITU. See CCITT

International Telecommunications Union. Formerly CCITT.

ITU -T

Telecommunication Standardization Sector of ITU.

ITU V.13

V.13 signaling allows your modem to communicate with non-Motorola modems. This
signaling operates when the modem is configured for synchronous mode.

ITU V.22 bis

2400 bps modem standard for use with dial and leased-line circuits.