YDIT professional analysis of the difference between VGA signal and RGB signal in the market

Source:YDIT 誉德 Release time:2019/7/9 8:31:38 Views:1042

 

(Paperless office system, ultra-thin integrated lifter, paperless conference system) The price of RGB signal matrix and VGA signal matrix on the market is quite different. Both of them transmit computer signals. What are the differences between the two signals? What? Is it like some people say that the VGA signal is an analog signal, and the RGB signal is a digital signal?

(Paperless office system, ultra-thin integrated lifter, paperless conference system) If the RGB signal refers to the popular RGBHV signal, the VGA signal and the RGB signal are the same signal, both red and green. Lan three primary color signals, plus horizontal synchronization signals and vertical synchronization signals, that is, RGBHV signals, they are all forms of component video signals, are analog signals, are not digital signals, that is, signals from the same nature and structure; The difference is that the requirements for transmission and processing are different (the technical standards are different). We know that the signal interface and the transmission cable transmit signals with signal loss, and generally speaking, the higher the frequency, the greater the loss under the same conditions. Therefore, for the RGBHV signal with low bandwidth, we can use the 15-pin D-type interface, generally 3+2 or 3+5 lines for cost saving. Since the bandwidth of the signal is not high, the frequency of the signal processing chip is also Not too high, this type of RGBHV signal is called VGA signal; for higher resolution, higher grayscale RGBHV signals, you must use five Q9 headers (each The branch signal is one), transmitted by an RGBHV signal cable composed of five broadband coaxial cables, and processed by a higher frequency chip, which is an RGBHV signal (a five-wire RGB signal).
RGB matrix switcher
In the RGB signal, the horizontal sync signal and the vertical sync signal are combined and transmitted by one line. This is RGBS (four-wire RGB signal), and then the composite sync signal is combined with the green signal or the blue signal, that is, the three lines. RGB signal. RGBS and RGB are often used extensively in graphics workstations and television broadcasts.
Therefore, the VGA signal mode is used to transmit and process RGBHV signals of tens to 100M bandwidth (paperless office system, ultra-thin integrated lifter, paperless conference system), while RGB mode is used to transmit and process 100M~200 M. Bandwidth RGBHV signal. (Requires the bandwidth of the processing device to be 2~3 times of the signal to meet the passage of the higher harmonics of the signal)
RGB signal and VGA signal are at standard level. Generally, the VGA signal transmission distance is only a few meters according to the standard. In engineering practice, it is unstable or even invalid after more than 15 meters. The RGB signal transmission bandwidth is only 10~50 meters according to the standard. In engineering practice, more than 60~80 meters is unstable or even ineffective; therefore, long-line transmission should be transmitted by twisted pair extender or optical transceiver (paperless office system, ultra-thin integrated lifter, paperless conference system) .