G
LOSSARY
79
digital loopback
A test that checks the modem's RS-232
interface and the cable that connects the
terminal
or computer and the modem. The
modem receives data (in the form of
digital
signals
) from the computer or terminal, and
immediately returns the data to the screen for
verification.
digital signals
Discrete, uniform signals. In this manual, the
term refers to the
binary digits
0 and 1.
Contrast with
analog signals
.
DTE
Data
terminal
(or terminating) equipment. A
computer that generates or is the final
destination of data.
duplex
Indicates a communications channel capable of
carrying signals in both directions. See
half
duplex
,
full duplex
.
Electronic Industries Association (EIA)
Group which defines electronic standards in
the U.S.
error control
Various techniques that check the reliability of
characters
(
parity
) or blocks of data.
V.42
and
MNP
error-control
protocols
use error
detection (
CRC
) and retransmission of flawed
frames
(
ARQ
).
facsimile
A method for transmitting the image on a page
from one point to another. Commonly referred
to as fax.
