Multitech CommPlete MT5634HD8, User Manual, Page: 81 / 99

Glossary
CommPlete Communications Server 75
Chip : Also called integrated circuits (IC), they
are squares or rectangles that contain from a
few dozen to a few million electronic
components.
CHKDSK (pronounced “check disk”) : An
external DOS command that reports free
memory and disk space. CHKDSK must be run
directly from DOS or within a batch file.
Circuit : Any closed path through which
electrical current can flow.
Circuit-switched Network : A technology used
by the PSTN that allocates a pair of conductors
for the exclusive use of one communication path.
Circuit switching allows multiple
conversations on one talk path only if the end-
users multiplex the signals prior to
transmission.
Circuit switching : The temporary connection
of two or more communications channels using a
fixed, non-shareable path through the
network. Users have full use of the circuit until
the connection is terminated.
Clipboard : An electronic holding place for the
most recent cur or copy made from a document.
Whatever is on the clipboard can be pasted into
the current document. Only one item may be on
the clipboard at a time. When new copy is sent
to the clipboard the existing copy is
eliminated. When you shut down your
computer, whatever is on the clipboard is lost.
Clock : A timing signal generated by an
oscillating circuit which is used to synchronize
data transmissions.
Command : An instruction that tells a computer
to begin, continue, or end a specific operation.
Command mode : One of two states of an
intelligent (programmable) device. The mode
in which commands can be issued to alter
operating parameters.
Communications Server : Also known as the
Async Gateway, it is a PC equipped with the
appropriate hardware and software package so
it can function as a gateway between a LAN and
its modems or host connections.
COMx Port : A serial communications port on a
PC.
CONFIG.SYS file (pronounced “config dot
sis”)
: A text file that contains configuration
commands used when you start your computer.
Commands in the CONFIG.SYS file enable or
disable system features, set limits or resources,
and extend the operating system’s purpose by
loading device drivers.
Cooked data : A term used in UNIX
communications to identify the UNIX
command-line data transmitted. This type of
data is noted for a reduction in effective
throughput because it has to be processed, or
“cooked” prior to transmission. Compare with
raw data.
CPU (central processing unit) : The computing
part of the computer. It is made up of the
control unit and the ALU (arithmetic logic
unit). The CPU, clock and main memory make
up a computer. When you turn on your computer,
an electrical signal follows a permanently
programmed path to the CPU to clear the
leftover data from the chips’ internal memory
registers.
CRC (Cyclic Redundancy Check) : A field used
in packetized data that contains two 8-bit
BCCs (Block Check Characters) as the binary
result of an algorithm performed on the data
bits in the packet. A CRC is used for error
detection by many synchronous protocols.
CTS (Clear To Send signal) : With
communications between modems, an RSs-232
signal sent from the modem to the DTE that
indicates it is ready to accept data. Contract
with RTS.
D
DAA (Data Access Arrangement) : The
circuitry to isolate any device from phone lines
and their associated equipment.
Daisy-chain : A method of connecting multiple
devices in a series, one after another.
Data compression : The process of reducing the
data bits necessary to represent useful
information. By compressing files, less storage
is required and higher throughputs are
realized.
Data Pump : The DAC (Digital-to-Analog
Conversion) circuitry used within a modem.