Multitech CommPlete MT5634HD8, User Manual, Page: 80 / 99

MT5634HD8 User Guide
74 CommPlete Communications Server
uses 8-bit characters , to allow for control
characters (i.e., all non-ASCII files).
BSC (Binary Synchronous Communications) :
Also called “bisync”, this communications
protocol was the first synchronous data format
used by IBM. It is still in use, but is rapidly
being replaced by IBM’s newer Synchronous
Data Link Control (SDLC). Bisync is a byte-
synchronous protocol that has longer delays
and more overhead that the bit-synchronous
SDLC. It uses two synchronization characters to
head every packet.
Bit (Binary DigIT) : A bit is the basis of the
binary number system. It can take the value of 1
or 0. Bits are generally recognized as the
electrical charge generated or stored by a
computer that represents some portion of usable
information.
Bit-synchronous transmission : A synchronous
form of data transmission that focuses on a
maximum packet size rather than the length of
the characters the packet contains. SDLC is a
bit-synchronous protocol.
Boot : Starting or restarting your PC. This term
originates from the saying “to pull oneself up by
the bootstraps”.
Bps (bits per second) : A unit to measure the
speed at which data bits can be transmitted or
received. Bps differs from baud when more than
one bit is represented by a single cycle of the
carrier.
Break-out box : An electronic device which is
inserted between two RS232/V.24 connectors for
the monitoring of pin activity and for the re-
routing of lines (crossover).
Broadcast : To send information simultaneously
to a group of recipients.
Buffer : A temporary storage register or Random
Access Memory (RAM), used in all aspects of
data communications which prevents data from
being lost due to differences in transmission
speed. Keyboards, serial ports, muxes and
printers are a few examples of the devices that
contain buffers. A buffer allows one device to
dump data at a high speed and for the lower-
speed device to accept it at its own pace. In this
way, the high-speed device can continue to
work without having to wait for its data
transfer to end. Buffers are a way of preventing
potential data loss.
Bus : A common channel between hardware
devices either internally between components
in a computer, or externally, between stations in
a communications network.
Byte : The unit of information a computer can
handle at one time. The most common
understanding is that a byte consist of 8 binary
digits (bits), because that’s what computers
(PCs) can handle. A byte holds the equivalent
of a single character, such as the letter “A”.
C
CAD (computer aided design - pronounced
“kad”)
: A computerized system used to design
products. CAD systems are high speed
workstations or PCs that use CAD software and
input devices, such as graphic tables and
scanners.
Callback security : A security feature available
in some intelligent modems that stores phone
numbers. When activated, the user calling the
secured modem must furnish a recognized
password, and then provide a code that
corresponds to one of the stored phone numbers.
When these security measures are met, the
secured modem hangs up on the caller and dials
the appropriate number to establish a data
communications link.
Capacitor : An electronic device that stores an
electrical charge. It comes in varying sizes for
use in anything from power supplies to the tiny
cells in dynamic RAM chips. When the device
is powered down, it’s capacitors lose their
charge.
Carrier signal : An analog signal with known
frequency, amplitude and phase characteristics
used as a transport facility for useful
information. By knowing the original
characteristics, a receiver can interpret any
changes as modulations, and thereby recover
the information.
Character set : One of a number of coding
schemes which uses binary digits to represent
characters, numbers, punctuation, and/or control
characters. Common character sets are ASCII,
ANSI, and EBCDIC.
Checksum : A control field found in synchronous
data packets which contain the results of the
error control algorithm used.