Tech Source International Video Technical Reference
Types of Video Signals
Composite Video Blanking and Sync. RCA and BNC connectors. Typically associated with NTSC, PAL, and SECAM low resolution, interlaced signals. Has video, color, and sync signals combined in one carrier.
Separate Video. Four-Pin Mini-Din connector. An analog signal that separates the Brightness and Color components of the video signal. Slightly better than CVBS for image quality, associated with NTSC, PAL, and SECAM interlaced signals.
Component Video. Uses three RCA connectors. The signal is separated into Y (Brightness), Pb (difference between brightness and Blue component), and Pr (difference between brightness and Red component). Typically used in HD consumer products. Analog signal not as good as DVI or HDMI.
Video Graphics Array. Standard computer monitor interface. HD-15 D-Sub connector. Analog signal capable of running from VGA through UXGA. Utilizes separate R, G, B color and Horizontal and Vertical sync signals.
Digital Video Interface. Generic nomenclature for DVI-I and DVI-D connectors (see below). Maximum resolution of 3mp.
Digital Visual Interface-Digital. 24-Pin D-shaped connector, compatible with DVI-I connector from a mechanical standpoint. Pure digital signal, no analog component transmitted. Not as common as the DVI-I signal due to the universality of the DVI-I signal.
Digital Visual Interface-Integrated. 28-Pin D-Shaped connector. This has both the digital and analog components of the signal. The analog portion allows the signal to work with VGA connections when an adaptor is used.
Hi-Definition Multimedia Interface. 19-Pin connector, similar in size to a USB connector. Uncompressed Digital signal for video and audio. Capable of displaying up to Full HD signals. Typically used in comsumer HD applications.
Serial Digital Interface. BNC connector. Digital signal used in Broadcast industry.
Hi-Definition Serial Digital Interface. BNC connector. Used for Hi-Definition Broadcasting signals.
Digital Camera Interfaces
proven interface for industrial imaging
Less resource intense on host PC and guaranteed bandwidth results in higher sustained frame rates
4.5 meter max. cable, data & power via same cable
Laptop FireWire ports are 4-pin and do not supply power external power supply & 4-pin to 6-pin adaptor cable required.
480 Mbps data transfer
Bandwidth is not guaranteed and dependence of host PC for bus control reduces effective speed/frame rates.
5 meter max. cable length
Data & power in a common cable
Ubiquitous interface on current PCs.
Lowest cost and best ease of use for End Users.
GigE / Gigabit Ethernet
100 meter cables Standard CAT5e or CAT6
The IP Rating System
IP stands for Ingress Protection
The ratings first digit i.e. IP56 relates to the ingress protection against dust (5 means dust protected, see the table below) The second digit i.e. IP56 relates to the ingress protection against water (6 means protected against heavy water jets, see the table below)
IP First Digit Protection Against Solids
Protection against Human/Tool Contact
Protection against solid objects (foreign bodies)
No special protection
Back of hand, Fist
Large foreign bodies, >50mm diameter
Medium-sized foreign bodies,>12 diameter
Tools, thick wires etc
Small foreign bodies, >2.5mm diameter
Thin wires, screws etc
Granular foreign bodies,>1mm diameter
Complete protection, (limited ingress permitted)
Dust protected; dust deposits are permitted, but their volume must not affect the function of the unit.
IP Second Digit Protection Against Liquids
Protection against water
Protection from condition
No special protection
Water dripping/falling vertically
Water sprayed at an angle (up to 15Ί degrees from vertical)
Light rain with wind
Spray water (any direction up to 60Ί degrees from vertical)
Splashing/spray water from all directions, (limited ingress permitted)
Low pressure water jets from all directions, (limited ingress permitted)
Hose down, residential
High pressure water jets from all directions, (limited ingress permitted)
Hose down, commercial.
Submersible (temporary), 15 cm to 1M
Immersion in tank
Permanent Submersion, under pressure, over 1 M depth
For use underwater
NEMA defines standards for various grades of enclosures. Each is rated to protect against designated environmental conditions such as water, dust etc. The following is a description of the NEMA ratings, and their approximate IP-rating equivalents.
Approx. IP Equivalent
General-purpose. Protects against dust, light, and indirect splashing but is not dust-tight; primarily prevents contact with live parts; used indoors and under normal atmospheric conditions.
Drip-tight. Similar to Type 1 but with addition of drip shields; used where condensation may be severe (as in cooling and laundry rooms).
3 and 3S
Weather-resistant. Protects against weather hazards such as rain and sleet; used outdoors on ship docks, in construction work, and in tunnels and subways.
Intended for outdoor use. Provides a degree of protection against falling rain and ice formation. Meets rod entry, rain, external icing, and rust-resistance design tests.
4 and 4X
Watertight (weatherproof). Must exclude at least 65 GPM of water from 1-in. nozzle delivered from a distance not less than 10 ft for 5 min. Used outdoors on ship docks, in dairies, and in breweries.
Dust-tight. Provided with gaskets or equivalent to exclude dust; used in steel mills and cement plants.
6 and 6P
Submersible. Design depends on specified conditions of pressure and time; submersible in water or oil; used in quarries, mines, and manholes.
Hazardous. For indoor use in Class I, Groups A, B, C, and D environments as defined in the NEC.
Hazardous. For indoor and outdoor use in locations classified as Class I, Groups A, B, C, and D as defined in the NEC.
Hazardous. For indoor and outdoor use in locations classified as Class II, Groups E, F, or G as defined in the NEC.
MSHA. Meets the requirements of the Mine Safety and Health Administration, 30 CFR Part 18 (1978).
General-purpose. Protects against the corrosive effects of liquids and gases. Meets drip and corrosion-resistance tests.
12 and 12K
General-purpose. Intended for indoor use, provides some protection against dust, falling dirt, and dripping noncorrosive liquids. Meets drip, dust, and rust resistance tests.
General-purpose. Primarily used to provide protection against dust, spraying of water and noncorrosive coolants. Meets oil exclusion and rust resistance design tests.