Toshiba V.90 - Manual (Page 94)

Glossary 75
escape: 1) To cancel the task currently in progress. 2) A code (ASCII
code 27, generated by the Esc key) telling the computer that what
follows are commands, not data. Used with peripheral devices such
as printers and modems.
Error control: Detection of errors in data communication. Requests
retransmission of data in which errors were found.
Escape control: This code is used to return to the command state without
disconnecting the line when the internal modem is online.
F FIFO: First-In/First-Out means the first data that enters a buffer is the
first to be retrieved.
Fallback: Reduction of a modem’s speed. If the remote modem cannot
communicate as fast as the local modem, the local modem will
reduce its speed.
firmware: A set of instructions built into a chip to control its activities.
Flow control: Flow control ensures smooth data communication. If
operating speed differs between the personal computer and modem
or between your modem and a remote modem and if the remote
station runs short of buffer capacity, a transmission halt request is
sent from the receiver to the transmitter. When the receiver has
enough buffer capacity to resume receiving data, a transmission
restart request is sent. There are two ways of flow control, XON and
OFF control codes and CTS and RTS signals.
frequency: The number of times a signal repeats an identical cycle within
a certain time period.
full duplex: A type of data transmission in which data flows between two
devices in both directions simultaneously. See also half duplex.
G gigabyte (GB): A unit of data storage equal to 1,073,741,824 bytes (1024
x 1024 x 1024 bytes). See also byte.
Guard time: An interval before and after an escape sequence that
prevents the modem from interpreting the escape sequence as data.
H half duplex: A type of data transmission in which data flows between
two devices in one direction at a time. See also full duplex.