US Robotics COURIER HST User'smanual page 115

COURIER HST
Binary Digit
Bit Rate
BPS
Buffer
A 0 or I , reflecting the use of a binary numbering system
(only two digits). Used because the computer recognizes
either of two states, OFF or ON. Shortened form of binary
digit is ""bit."
The number of binary digits or bits transmitted per second
(bps). Communications channels using telephone channel
modems are established at set bit rates, commonly 110, 300,
1200. 2400, 4800, 9600, and 144000.
The bits (binary digits) per second rate.
A memory area used as temporary storage during inpuU
output operations. Two examples in the Courier HST are
the command buffer (last issued command) and the flow
control buffer (for data flow control and storing copies of
transmitted frames until they are positively acknowledged
by the receiving modem).
Byte A group of binary digits stored and operated upon as a
unit. A byte may have a coded value equal to a character
Carrier
CCITT
Character
Characters Per
Second
G-2
in the ASCII code (letters, numbers), for example, or have
some other value meaningful to the computer. In user docu-
mentation, the term usually refers to 8-bit units or charac-
ters. I kilobyte
=
1,024 bytes or characters; 64k
=
65,536
bytes or characters.
A continuous frequency capable of being either modulated
or impressed with another information-carrying signal. Carri-
ers are generated and maintained by modems via the trans-
mission lines of the telephone companies.
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 CC ITT V. 22. For
2400 bps communication, most U.S. manufacturers observe
V. 22bis. The initials CC ITT represent the French name; in
English it's known as the International Telegraph and Tele-
phone Consultative Committee.
A representation, coded in binary digits, of a letter, num-
ber, or other symbol.
A data transfer rate generally estimated from the bit rate and
the character length. For example, at 2400 bps, 8-bit charac-
ters with Start and Stop bits (for a total of ten bits per char-
acter) will be transmitted at a rate of approximately 240