11. APPENDIX
A
ActiveX
ActiveX is Microsoft software component technology, mainly used by
Microsoft Windows. This protocol facilitates the sharing of information
between different components in a networked environment.
AGC (Automatic Gain Control)
This function automatically adjusts the amount of increase depending on the
strength of the incoming signal.
AI (Auto Iris)
A very useful approach to control the strength of lights. This function
automatically detects the light level of image to determine the movement of
the device. Basically the auto iris opens or closes the lens iris as the light
turns dimmer or brighter.
Alarm Input
This facility allows various forms of external alarms, such as door contact,
reed switched, Passive Infra-red detector, or vibration sensors, to be
connected to the security camera. As receiving an alarm signal, the specific
camera will be switch on.
Analog Signal
Analog signals are continuous rather than discrete or pulsed, varying in
voltage, frequency, or phase of quantities.
Angle of view
Also known as viewing angle, this refers to the available angular range
within a certain image size. The smaller the focal length, the wider the
angle of view is.
Aspect Ratio
Aspect Ratio refers to the ratio of width to height in images. 4:3 is a common
aspect ration used in television screens and computer monitors.
