We all know that DVI (Digital Visual Interface) is a digital computer interface. DVI transmits digital signals. Compared with past VGA signals, DVI signals have great advantages, such as fast transmission speed, elimination of tailing, no attenuation of signals, and clear picture. However, under the current technical conditions, DVI also has a big disadvantage, that is, the transmission distance is short. Under normal circumstances, the general DVI cable can only effectively transmit signals about 5 meters, and the attenuation of the signal will occur if it exceeds 5 meters. This shortcoming greatly limits the popularity and application of DVI devices. Therefore, how to extend the transmission length of DVI signals becomes an imminent problem. Companies are working hard to find the most economical and effective way. We have synthesized a few more mature methods and gave you an introduction.
1. Use special DVI fiber optic cable
A typical DVI cable is a copper core that cannot be used for long distance transmissions. The special cable is made by adding fiber to the base of the copper core cable and making it into a DVI fiber cable. This cable can be transported up to 500 meters. The highest resolution supports 1920x1200. This cable has a DVI connector on both sides for direct connection to a computer and display. Advantages: The connection is simple and does not require any intermediate links.
Disadvantages: high cable cost, thick cable, not suitable for long-distance wiring, if you want to wear a tube, it is recommended to use the high-definition tube-type DVI cable.
2. Use signal amplifiers and repeaters
If the transmission distance is around 30 meters. A signal amplifier or repeater can be used. The difference between them is that the amplifier is placed at the front end of the DVI cable, and the signal is amplified by a cable; the repeater, as the name suggests, is placed in the middle of the two DVI cables to relay signals. Comparing the transmission distance and the supported resolution and cost, the two devices are basically the same, but they are selected according to the different needs of the users, so we put them in the same category. Usually signal amplifiers and repeaters can effectively transmit 1920x1200 signals to 15 meters, and transmit 1280x1024 DVI signals to 30 meters, using a normal DVI cable. Both devices are suitable for medium to short range transmission. Advantages: small, convenient, and relatively low cost.
Disadvantages: Not suitable for long distance transmission.
3. Transmission over twisted pair (CAT-5e)
Suitable for medium distance transmission, usually 1290x1200 signals can be transmitted 50 meters, and low resolution signals will be transmitted longer. DVI twisted pair transmitter includes a transmitter and a receiver, and some manufacturers need to supply power at both ends.
Home products only need to be powered at one end. While transmitting the DVI signal, a DDC signal is also needed to identify the resolution and other signals. Therefore, the transmitter and the receiver are generally connected by two twisted pairs, and the DVI signal and the DDC signal are respectively transmitted. Although the DVI twisted pair transmitter has a certain cost, the twisted pair is low cost and easy to route, and the transmission distance is relatively long, which reduces the average cost, so this method becomes a generally accepted method. Advantages: cost average and convenient wiring.
Disadvantages: Two devices, the receiver and the transmitter, are added between the computer and the display, and the installation is relatively complicated.
4. The use of fiber optic cable transmission equipment is suitable for long-distance transmission, up to 500 meters.
This is different from the first one in that it uses a common fiber optic cable, LC multimode or ST cable, while the first method uses a special cable. It works in much the same way as a twisted pair transmitter, using a pair of transmitters and receivers, transmitting DVI signals with fiber optic cables, and transmitting DDC signals with one twisted pair.
Advantages: long transmission distance
Disadvantages: The optical cable is relatively brittle, easy to break, and pay more attention when wiring.
5. Connect two ultra-long DVI copper cables in series (up to 80 meters)
This method can basically meet the indoor transmission distance required in the current project. One key point in choosing this method is to require the quality of the DVI cable to be excellent. For example, two 40-meter DVI cables or two 40-meter engineering-grade HDMI cables from Rui HD can be connected in series to 80. Meter lossless transmission.
Advantages: moderate cost and strong stability.
Disadvantages: Up to 80 meters can be transmitted and the distance is limited.