U-90E Data/Fax Modem
Glossary
H
Stop bit
: In asynchronous transfers, every character is terminated by one or two stop bits which show
where a character ends.
Synchronous
: In synchronous transfer, a dedicated control signal line transmits a clock signal which
paces the transmitted data. In highspeed connections, the transfer between two modems is always
synchronous, even if the DCE to DTE connection is asynchronous.
T.30
: A standard for fax transfers.
TAE6
: A standard for a telephone wall outlet used in some countries, particularly in Germany.
ter
: Old French word for three.
Terminal equipment
: A computer running terminal software is used as terminal equipment in modem
connections.
Terminal program
: A program which emulates the operation of a hardware terminal on a computer's
screen and keyboard.
Token
: A token is a reencoding of information in less bits; basically an abbreviation.
Transfer mode
: Data can be transferred either synchronouosly or asynchronously.
Transfer rate
: The speed at which the data bits are effectively transferred.
UART
: Universal Asynchronous Receiver and Transmitter; a special IC chip which controls the serial port.
Different models are available for PCs. Models with an internal buffer usually allow higher transfer rates.
V.
: The ITU-TSS V. - standards describe data transfer via telephone lines.
Western jack
: Telephone wall outlet connector used in the USA and other countries.
X.
: The ITU-TSS X.-standards describe data transfer in public data networks.
XModem
: A widely used, though somewhat aged, file transfer protocol. The use of 128 byte data blocks
severely limits the achievable throughput.
XON/XOFF
: Software flow control. The data flow is stopped by sending ASCII character Control-Q (dec.
17; hex $11) and restarted by Control-S (dec. 19; hex $13).
YModem
: A file transfer protocol which uses data blocks of 1 Kbyte and transfers filenames and more than
one file in one transfer.
