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Pan/Tilt Head

A motorized unit permitting vertical and horizontal positioning of a camera and lens combination.  Usually 24V AC motors are used in such P/T heads, but also 110V AC, i.e., 240V AC units can be ordered.

Pan Unit, also refer to Scanner

A motorized unit permitting horizontal positioning of a camera.

Password

A security measure used to restrict logon names to user accounts and access to computer systems and resources.  A password is a string of characters that must be provided before a logon name or an access is authorized.  A password can be made up of letters, numbers, and symbols, and it is case sensitive.

Patch cord

It is a flexible piece of cable terminated at both ends with plugs.  Used for interconnecting circuits on a patch board, in a wiring closet or at the work area.

Peak-To-Peak, pp

The amplitude (voltage) difference between the most positive and the most negative excursions (peaks) of an electrical signal.

Phase Alternation Line, PAL

PAL is the dominant format in the World for analog television broadcasting and video display and is based on a 625 line, 50 field/25 frames a second, 50HZ system. The signal is interlaced, like NTSC into two fields, composed of 312 lines each.  PAL is used mainly in Europe, China, Malaysia, Australia, New Zealand, the Middle East, and parts of Africa.  PAL-M is a Brazilian colour TV system with 525 lines per frame, 30 frames and 60 fields per second.

Picture Elements, Pixel

One spot in a rectilinear grid of thousands of such spots that form an image produced on the screen by a computer or on paper by a printer. A pixel is the smallest element that display or print hardware and software can manipulate to create letters, numbers, or graphics.  Pixels per inch (PPI) or pixel density is a measurement of the resolution of video image to be printed within a specified space.  A digital image is made up of many pixels.  Each pixel has a color.  When the pixels are arranged next to each other, the resulting image looks like something. When a digital image is described in inches, it is being calculated, based on the Monitors Resolution, or on the printers resolution (Both of which are different and non-related, thus causing a lot of confusion).

Picture Freeze

The Lotus BC-23XP and BS-3451P series are equipped with a Picture Freeze function that allows for the output of a still image while the camera is panning, tilting, zooming, focusing, initialising the lens, or performing pre-set operations.  For example, the camera will output a still image before it begins to pan, tilt, or zoom, and once the operation is completed, the camera continues to display images.  Unnecessary images are not displayed.  Environmentally-friendly lead-free design Lotus BC-23XP and BS-3451P series cameras use lead-free solder and halogen-free printed-circuit boards, making the camera environmentally friendly.

Plastic

It is kind of high polymeric substances, including both natural and synthetic products that are capable of flowing under heat and pressure, called thermoplastics.  Unlike rubber and other thermoset compounds, plastics can be remelted and reused.

Plenum

It is a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.  A description for a cable that passes the NFPA 262 (UL-910) CMP flame test requirements.

Point-to-Point Protocol,  PPP

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. 

Point-to-Point Tunneling Protocol, PPTP

A protocol 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). 

Point-to-Point Protocol over Ethernet (PPPoE)

It is a specification for connecting users on an Ethernet network to the Internet through a broadband connection, such as a single DSL line, wireless device, or cable modem.  Using PPPoE and a broadband modem, LAN users can gain individual authenticated access to high-speed data networks.  By combining Ethernet and Point-to-Point Protocol (PPP), PPPoE provides an efficient way to create a separate connection for each user to a remote server.

Polyethylene, PE

PE is a thermoplastic material having excellent electrical properties.  It offers low dielectric constant, a stable dielectric constant over all frequencies, very high insulation resistance.  In terms of flexibility, polyethylene can be rated stiff to very hard, depending on molecular weight and density-low density being the most flexible and the high-density, high-molecular weight formulation being very hard.  Moisture resistance is rated excellent.

Polyvinyl Chloride, PVC

PVC is a general purpose thermoplastic used for wire and cable insulation and jackets.

Port

It is a connection point on your computer where you can connect devices that pass data into and out of a computer.  For example, a printer is typically connected to a parallel port (also called an LPT port), and a modem is typically connected to a serial port (also called a COM port).

Power

It is the amount of work per unit of time, usually expressed in watts.  Power equals the product of voltage and current (P = V x I).

Power over Ethernet, PoE

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. 

Preset iris

Diaphragm with two setting rings or one ring that can be moved to two positions.  One is click-stopped, but does not affect the iris, the other moves freely and alters the aperture.  The required aperture is preset on the first ring, and the iris closed down with the second just before exposure.

Pre/post alarm images

These are 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.

Protocol

It is a set of rules and conventions for sending information over a network.  These rules govern the content, format, timing, sequencing, and error control of messages exchanged among network devices.

Pulse-code modulation, PCM

Is a digital representation of an analog signal where the magnitude of the signal is sampled regularly at uniform intervals, then quantized to a series of symbols in a numeric (usually binary) code.