Axis 206 User Manual page 37

own names.
PAL (Phase Alternating Line) - PAL is an analog color
encoding system used in television systems in Europe and in
many other parts of the world. PAL defines the video signal
using 625 TV lines per frame, at a refresh rate equal to 25
frames per second. See also NTSC.
PDA (Personal Digital Assistant) - A small handheld
computer, which usually provides at least a calendar, an
organizer and a notepad.
PEM (Privacy Enhanced Mail) - An early standard for
securing electronic mail. The PEM-format is often used for
representing an HTTPS certificate or certificate request.
Ping - Ping is a basic network program used diagnostically
to check the status of a network host or device. Ping can be
used to see if a particular network address (IP address or
host name) is occupied or not, or if the host at that address
is responding normally. Ping can be run from e.g. the
Windows Command prompt or the command line in Unix.
Pixel (Picture Element) - A pixel is one of the many tiny
dots that make up a digital image. The color and intensity of
each pixel represents a tiny area of the complete image.
PoE (Power over Ethernet) - Power over Ethernet provides
power to a network device via the same cable as used for the
network connection. This is very useful for IP-Surveillance
and remote monitoring applications in places where it may
be too impractical or expensive to power the device from a
power outlet.
PPP (Point-to-Point Protocol) - A protocol that uses a serial
interface for communication between two network devices.
For example, a PC connected by a phone line to a server.
PPTP (Point-to-Point Tunneling Protocol) - A protocol (set
of communication rules) that allows corporations to extend
their own corporate network through private "tunnels" over
the public Internet. In this way a corporation can effectively
use a WAN (Wide Area Network) as a large single LAN
(Local Area Network). This kind of interconnection is known
as a virtual private network (VPN).
Pre/post alarm images - The images from immediately
before and after an alarm. These images are stored in a
buffer for later retrieval.
Progressive scan - Progressive scan, as opposed to
interlaced video, scans the entire picture, line by line every
sixteenth of a second. In other words, captured images are
not split into separate fields as in interlaced scanning.
Computer monitors do not need interlace to show the
picture on the screen, but instead show them progressively,
on one line at a time in perfect order i.e. 1, 2, 3, 4, 5, 6, 7
etc., so there is virtually no "flickering" effect. In a
surveillance application, this can be critical when viewing
detail within a moving image, such as a person running. A
high-quality monitor is required to get the best from
progressive scan. See also Interlacing.
Protocol - A special set of rules governing how two entities
will communicate. Protocols are found at many levels of
communication, and there are hardware protocols and
software protocols.
Proxy server - In an enterprise that uses the Internet, a
proxy server acts as an intermediary between a workstation
user and the Internet. This provides security, administrative
control, and a caching service. Any proxy server associated
with a gateway server, or part of a gateway server,
effectively separates the enterprise network from the outside
network and the local firewall. It is the firewall server that
protects the enterprise network from outside intrusion.
PTZ (Pan Tilt Zoom) - A PTZ-enabled camera can be
remotely controlled so as to change the view from the
camera. Panning is the movement of the camera along its
horizontal axis, tilting is the movement of the camera along
its vertical axis, and zooming is the adjustment of the zoom
lens to magnify the view.
Quad view - A Quad view displays images from up to four
cameras on a single screen; where the images from each
camera take up approximately a quarter of the display area.
Remote monitoring - Network video gives users the ability
to gather information at all key points of an operation and
view it in realtime. This makes the technology ideal for
monitoring equipment, people and places, both locally and
remotely. Application examples include traffic and
production line monitoring, and the monitoring of multiple
store locations.
Resolution - Image resolution is a measure of how much
detail a digital image can hold: the greater the resolution,
the greater the level of detail. Resolution can be specified as
the number of pixel-columns (width) by the number of
pixel-rows (height), e.g. 320x240.
Alternatively, the total number of pixels (usually in
megapixels) in the image can be used. In analog systems it
is also common to use other format designations, such as
CIF, QCIF, 4CIF, etc.
RS-232 - A long-established standard that describes the
physical interface and protocol for low-speed serial data
communication between devices. This is the interface that
e.g. a computer uses to talk to and exchange data with a
modem and other serial devices.
RS-422 - A serial data communication protocol that
specifies 4-wire, full-duplex, differential line, multi-drop
communications. It provides balanced data transmission
with unidirectional/non-reversible, terminated or
non-terminated transmission lines. RS-422 does not allow
multiple drivers, only multiple receivers. Maximum
recommended range is 4,000 feet (1200 meters). Maximum
recommended baud rate is 10Mbit/s.
RS-485 - An upgraded version of RS-422 that supports up
to 32 devices on the same connection. RS-485 is an
electrical specification of a two-wire, half-duplex,
AXIS 206 - Glossary
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