AS NZS IEC 62676.3:2020 pdf free download – Video surveillance systems for use in security applications
4.2.1 General
The physical interfaces of video surveillance devices are used to connect devices through fiber optic or video cables etc., as shown in Figure 2. It is the elementary interface to ensure reliable transmission of the analog and digital signals as well as the related control signals. This physical interface is usually one part in physical layer of the ISO OSI model. The physical interface can include connectors (e.g. BNC, RCA, FC, ST, SC, LC, DIN, dB9) or cables (e.g. coaxial, twisted-pair, fiber-optic) for wired transmission or air with a certain electromagnetic spectrum (e.g. RF, microwave, infrared) for wireless transmission.
4.2.3.3 Digital video input interface
A display monitor may use a number of digital video interfaces such as Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI), Displayport and SDI. Those standards shall be based on the requirements of IEC 6231 5-1 , which defines the requirements on video outputs for uncompressed digital video interfaces and is applicable to a variety of standard digital video-related high-speed physical interfaces. DVI video interface should use DVI-D or DVI-I connectors. The connectors should be connected to DVI-D or DVI-I cables. HDMI video interface should use connectors defined in the HDMI1 .0, HDMI1 .3 and HDMI1 .4 specifications. The interface should use cables defined in the HDMI1 .4 specification. DisplayPort video interface should use connectors and cables compliant with DisplayPort version 1 .0, 1 .1 and 1 .2. SDI (SDI, HD-SDI/3G-SDI, HDcctv) interface should use the same connectors and cables as cameras with SDI output (see 4.2.2.3).
5.2.4.6 VESA VSIS video signal characteristics standard compliance
The analog video signal of the video transmission device, media or combination of both shall be compliant to the VESA Video Signal Standard (VSIS) Version 1 , Rev. 2, December 1 2, 2002 or later. This standard establishes the analog video signal characteristics for today’s video display interfaces.
8.3.2 Preparation of the test
A TV-signal generator providing a grey scale signal shall be connected to the terminated equipment input. The amplitude and the blanking reference voltage of the input and output signals shall be monitored on a dc-coupled waveform monitor.
8.3.3 Test procedure
The input and output impedance and return loss shall be determined by measuring the return factor, using dedicated reflector devices or by using a Wheatstone bridge in accordance with Figure 3. The signal generator shall be able to provide a frequency sweep from 0,1 MHz to 5 MHz. The differential capacitor is adjusted to achieve proper high frequency balancing of the source. R n is the reference resistor (75 Ω) with a tolerance of less than 0,5 %, R x is input or output impedance of the transmission equipment for measurement of the input and output impedance, respectively. The oscilloscope is used to measure the unbalance voltage U 2 as a function of the applied input voltage U 1.