By PURPLELEC | 29 June 2023 | 0 Comments
What are the functions of the VGA extender
The network cable VGA extender is mainly composed of a transmitter and a receiver, which can quickly transmit high-resolution RGB signals, RS232 control signals and audio over long distances through network cables. It is mainly manufactured for reliability and excellent high-resolution image quality. It adopts unique all-digital zero-compression technology to realize perfect pixel-by-pixel computer video transmission, and the highest resolution can reach UXGA (1600X1200).
Specifically designed for AV systems, the FOX500 also includes many integrator-friendly features such as image adjustment and calibration, dual RGB and audio outputs for sinks, multi-position RS-232 control, rack-mount capability, and real-time system Monitoring, etc., VGA to HDMI.
In order to solve the VGA transmission problem in engineering, VGA signal amplifiers began to emerge. It adopts the amplification principle and uses VGA video cables as the transmission medium, which can transmit the VGA video signal of the computer for hundreds of meters. However, people later discovered its shortcomings. The long-distance VGA wire is thick and hard, and it is not easy to find. It needs to be customized in the factory.
The VGA cable itself determines its poor anti-interference. As the distance increases, some interferences that were not very strong at first become stronger in the long-distance wire. Some amplifiers amplify the interference signal at the same time, resulting in some experimental conditions. It can be successful but the actual project has been done, but there is no way to apply it at all, resulting in huge losses for rework. In order to solve these problems in transmission, new technologies and ideas have emerged. A VGA video extender that uses ordinary network cables as the transmission medium has become an upstart in VGA video transmission technology, VGA to HDMI.
This transmission method adopts a transmitter and a receiver. The transmitter re-encodes the VGA video signal and transmits it on the network cable with differential signal technology, and then decodes and restores it to VGA at the remote receiver. Because the high-frequency attenuation of the wire characteristics of the network cable is large, the restoration and compensation technology of the back-end absorber is very important. If the technical solution is not good, there will be problems such as poor color restoration effect, smearing and ghosting. Many products are adjusted by graded and segmented DIP switches. This design idea is very good. However, in actual use, this method cannot complete accurate adjustments because the quality of the network cables used by the engineering company is different and the site environment is different. The purpose is also very troublesome for users to use.
The differential technology adopted by the VGA video extender itself has strong anti-interference performance, and with some technical solutions, the anti-interference performance has been greatly improved. Even the worst power plant strong electric and strong magnetic environment can use it to transmit VGA video over a long distance. Anti-interference is the main index to ensure the quality of the project. How to ensure the anti-interference of the product shows the degree of the R&D personnel who design the circuit. Different products have different anti-jamming effects. If you have the conditions, you’d better do the interference test first when choosing a product. If you don’t have the conditions, you’d better test it on-site or in a worse condition than the on-site before finalizing the purchase. Only in this way can the quality of the project be recognized by Party A and the smooth cooperation between the two parties can be ensured.
The technology of twisted-pair cable transmission of VGA video is to use 3 pairs of wires in the network cable to transmit the RGB signal of VGA video, and encode the two HV signals into RGB for transmission. It not only solves the internal crosstalk problem in long-distance transmission by using the characteristics of the network cable, but also saves a pair of wires to transmit other signals, so that the twisted pair transmission equipment has more functions and is more widely used.
It is cheap to use the network cable as the wire material, the crystal head is easy to manufacture, and the wiring is also convenient. At present, the price difference between VGA video extender and VGA signal amplifier is not big. The farther the distance is, the lower the wire cost is and the better the anti-interference effect is. It can be said that it is a trend to replace the VGA signal amplifier with a VGA video extender at a distance of more than 30 meters.
Leave a Reply
Your email address will not be published.Required fields are marked. *