VeriFone Omni 3200 Reference Manual page 172

Omni 3200 Reference Manual
C-2
Asynchronous Communication. A system in which each event
or operation starts as a result of a signal that the previous operation is
complete and the microcomputer is now ready for the next operation.
Asynchronous machines do not use a master clock for overall control.
See 'Synchronous Communication'.
ATM. Abbreviation for 'Automated Teller Machine'. The Omni 3200
magnetic stripe card reader can read data stored on track 3 of a
standard ATM card.
Bar Code. Optical binary code imprinted on merchandise in retail
stores. To support specific applications, an optional bar code reader
can be attached to the Omni 3200 to read and process bar codes.
Bar Code Reader. A pencil- or wand-shaped optical scanner used
to read bar codes. To read the code, you drag the tip of the bar code
reader across the length of the bar code, in a left-to-right or right-to-
left direction.
Baud. The number of times per second that a system, especially a
data transmission channel, changes state. The state of a system may
represent a bit, digit, or symbol. For a POS terminal, the baud rate
indicates the number of bits per second that are transmitted or
received by the terminal's serial ports and modem.
BCC. Abbreviation for 'Block Check Character'. The result of a
transmission verification algorithm accumulated over a transmission
block, and normally appended at the end. Block checks are performed
in longitudinal and cyclical redundancy checks. See 'LRC'.
Bit. Short for 'binary digit'. Either of the two digits 0 and 1 in the
binary number system. Also, a unit of information equal to one binary
decision. The bit is the smallest unit of storage and hence of
information in any binary system within a computer (or terminal).
Block. A collection of data units such as words, characters, or
records (generally more than a single word) that are stored in adjacent
physical positions in memory or on a peripheral storage device. A
block can therefore be treated as a single unit for reading, writing, and
other data communication operations.