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Glossary
68
PAL (Phase Alternate Line)
color TV signals used in West Germany, England, Holland, Australia, and several other
countries. It uses an interlaced format with 625 lines per frame at 25 frames per second.
PoE (Power over Ethernet)
Ethernet cabling as defined in the IEEE 802.3af standard.
Shutter Speed
The speed at which the charge is read out from the imager chip. Adjusts
the light sensitivity of the camera. A faster (briefer) shutter speed can arrest the motion of a
fast moving object (reduce image blur), rendering it sharp. Fast shutter speeds allow less
light to all on the CCD and can darken the image. For fast shutter speeds, ensure there is
adequate lighting. Usually selected using DIP switches on the side of the camera.
Subnet Mask
A number used to identify a subnetwork so that an IP address can be shared
on a LAN.
True Day/Night
The incorporation of a moving mechanical IR filter within the camera
ensures true 24 hour surveillance, providing high quality color images during the day and
similar quality black & white images at night when used with IR lighting.
UPS (Uninterruptible Power Supply)
ofhigh security systems, whose purpose is to back up the system when the main power
fails.
A standard of specifications for television transmission for
A method of powering Ethernet-connected devices via the
These are power supplies used in the majority
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