Appendix: Glossary
MicroLink 33.6TQV / MicroLink 28.8TQV / MicroLink 14.4TQ
Manual © 1997 ELSA GmbH
103
G
Glossary
Adaptive modem
This designates a
→
modem which automatically adapts itself to the
transmission bit rate of the remote station. ELSA was the first manufacturer
to obtain a postal registration for an
adaptive modem
and is using an
optimized method according to ITU-T V.100. Since then every modem
delivered by ELSA is adaptive according to V.100.
ASCII
The
A
merican
S
tandard
C
ode for
I
nformation
I
nterchange
is the most
commonly used international code to represent a 128 character alphabet. It is
also called
standard ASCII
, unlike
extended ASCII
, which is an extension of
the code
by international special characters and graphic symbols to a set of
256 characters (also called
IBM character set
). Standard ASCII can be coded
with a word length of 7 bits (2
7
= 128), whereas extended ASCII requires a
word length of 8 bits (2
8
= 256).
Asynchronous
In serial data transmission a method is needed to synchronize transmitter
transmission
and receiver in order to enable the receiver to detect the beginning and end of
a transmitted character. In
asynchronous transmission
this structuring is
achieved by marking each byte to be sent with one start bit and one or two
stop bits. Especially in the microcomputer sector, this start/stop method is
one of the most commonly used transmission methods, since, unlike
synchronous transmission, it is comparatively easy to perform.
AT command set
"Intelligent" modems are able to establish connections and accept calls
automatically. This requires a set of modem control commands. The
extended
AT command set
(AT = command prefix
AT
tention
) has become a
world-wide standard for the syntax of these commands. All ELSA modems are
equipped with an automatic dialing device and can accept calls automatically.
They use an extended AT command set, depending on the respective modem
type.
Baud
Baud
(abbreviation: Bd) is the unit for the step rate (1 Bd = 1 step per second),
i.e. the frequency of status changes on a transmission channel per second.
Erroneously, the unit Baud is often confused with the transmission rate
measured in
→
bps. In the case of signals having only two states, the step
rate is identical with the transmission rate. Rates over 1200 bps are,
however, normally performed by transmission of four, eight or more bits per
step, so that in these cases the step rate is lower than the transmission rate.
Example: V.32 = step rate 2400 Baud, transmission rate 9600 bps.
BBS
Abbreviation of
B
ulletin
B
oard
S
ystem
(also called Electronic Mail System). A
BBS
is an automatic information system with one or more connections to a
telephone network or digital networks like the ISDN. The users of a BBS
usually have the opportunity to send messages to each other and to use the
BBS as a communication forum. In addition, many BBS's are offering libraries
containing software and information about various areas. The
ELSA ONLINE
Support BBS, which can be accessed with the phone 49-241-9177-
