Multitech MT5634HD16 User Manual page 72

MT5634HD8/16 User Guide
Pulse dialing: One of two methods of dialing a telephone,
usually associated with rotary dial phones. Compare with
tone dialing.
Pulse-width: Pertaining to a digital signal. Pulse width
refers to the duration of one state between clocking signals.
Pulse width roughly corresponds to an analog signal's
wavelength.
Q
QAM (Quadrature Amplitude Modulation): A complex
method of modulation that establishes twelve phase angles
and four amplitudes, designating sixteen possible
combinations. QAM encodes hexadecimal values (also called
quadbits) into one cycle of the carrier. Using a 1800 bps
carrier frequency and a 2400 baud signaling rate, QAM
provides a 9600 bps modulation speed. However, because it
uses amplitude modulation, QAM is susceptible to noise.
Queue: A set of activities that are waiting in chronological
order for an action, such as printing, to be performed.
R
Rack: A frame or cabinet into which components are
mounted. The industry standard rack is 19" wide and has
variable depth and height.
Rackmount: A packaging style available for many types of
electronic equipment which enables the installer to mount
the equipment in an industry standardized enclosure. The
rackmount equipment is fitted with brackets, rather than
being packages in its own enclosure. Rackmounting
conserves disk and floor space (real estate) and often
conserves power outlets.
RAM (Random Access Memory): A computer's primary
workspace. All data must be stored in RAM (even for a short
while), before software can use the processor to manipulate
the data. Before a PC can do anything useful it must move
programs from disk to RAM. When you turn it off, all
information is RAM is lost.
Reboot: Restarting your PC by turning off the power and
then turning it back on, or by pressing Alt,Ctrl and Del keys
at the same time. Warm boot=Ctrl+Alt+Del (soft boot) or
Cold boot=Power switch (hard boot).
Repeater: A device that amplifies or regenerates the data
signal in order to extend the distance of the transmission.
This can be used with both analog and digital signals, and is
used extensively in long distance transmission to keep
signals from losing their strength.
Resolution: Indicates the number of dots that make up an
image on a screen or printer. The more dots, the higher the
resolution, and the finer and smoother the images can
appear when displayed at a given size.
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RJ-11: An industry standard interface used for connecting a
telephone to a modular wall outlet; comes in 4-and 6-wire
packages.
RJ-45: An 8-wire modular connector for voice and data
circuits.
ROM (Read Only Memory): A memory chip that
permanently stores instructions and data. Its contents are
created at the time it is manufactured and cannot be altered.
ROM is used to store control routines in PCs and peripheral
controllers. ROM is also used in the plug-in cartridges for
printers and video games. A set of ROM chips contain the
basic input/output system (BIOS).
RS232-C: An EIA standard for a serial interface between
computers and peripheral devices (modem, mouse, etc.). It
uses a 25-pin DB-25, or a 9-pin DB-9 connector. The RS232
standard defines the purposes, electrical characteristics and
timing of the signals for each of the 25 lines.
RTS (Request To Send signal): With communications
between modems, an RS232 signal sent from the DTE to the
modem requesting permission to transmit. Contrast with
CTS.
S
Scanner: A hardware device that can "read" a photograph or
other piece of artwork and transforms it into a collection of
dots that can be stored as a bit-mapped file on a hard drive.
It can then be manipulated into various software programs
and placed electronically in a page layout program.
SDLC (Synchronous Data Link Control): In IBM's SNA
networks, this is the primary data link protocol.
Serial Port: The connector on a PC used to attach a serial
device (a device that need to receive data one bit after
another), such as a mouse, printer or modem. It consists of a
9- or 25-pin connector that sends data in sequence. Serial
ports are referred to as "COMx" ports, where x is 1 to 4
(COM1 through COM4). A serial port contains a conversion
chip called a UART, which translates between internal
parallel and external serial formats.
Server: A computer that provides disk space, printer access,
or other shared services, to computers over a network.
Software: The set of instructions that make computer
hardware perform tasks. Programs, operating systems,
device drivers and applications are all software.
Spoofing: A command recognized by modems which have
been manufactured specifically for use within the UNIX
UUCP (UNIX to UNIX Copy) facility. Spoofing is the process
of transparently disabling the "g" protocol used by UUCP
and substituting the modem's own error correction protocol
for data integrity. The process "spoofs" the UNIX host into
CommPlete Communications Server