Glossary
37
fax mode
The mode in which the faxmodem is capable of
sending and receiving files in a facsimile format.
See definitions for V.17, V.27ter, V.29.
flow control
A mechanism that compensates for differences in
the flow of data into and out of a modem or other
device. See commands
&Hn, &In, &Rn.
frame
A data communications term for a block of data
with header and trailer information attached. The
added information usually includes a frame
number, block size data, error-check codes, and
Start/End indicators.
full duplex
These signals will flow in both directions at the
same time over one line. In microcomputer
communications, may refer to the suppression of
the online local echo.
half duplex
These signals will flow in both directions, but only
one way at a time. In microcomputer
communications, may refer to activation of the
online local echo, which causes the modem to send
a copy of the transmitted data to the screen of the
sending computer.
Hz
Hertz is a frequency measurement unit used
internationally to indicate cycles per second.
ITU-T
An international organization that defines
standards for telegraphic and telephone equipment.
For example, the Bell 212A standard for 1200 bps
communication in North America is observed
internationally as ITU-T V.22. For 2400 bps
communication, most U.S. manufacturers observe
V.22 bis.
