Common cable transmission distance summary data transmission is no longer difficult

The distance of cable transmission has always been a concern of weak electricians. It is also frequently discussed in the weak VIP technology group. We are dealing with cables every day, and we can clearly understand the use of cables in order to be able to work in the project. In this issue, we will come together to understand The commonly used cable transmission distance.

First, the network cable

The network cable is also a twisted pair cable, which has different transmission distances according to different specifications of the network cable. The network cable transmits the network signal. If the distance beyond the network cable itself is exceeded, the signal will be attenuated. In severe cases, the network signal will be interrupted.

Five categories, six categories are 100 meters, regular oxygen-free copper Category 6 line can reach 120 meters or so, if you want to increase the transmission distance, you can install repeaters between the two twisted pairs, you can install 4 relays Device. If you install 4 repeaters to connect 5 network segments, the transmission distance can reach 500m.

Second, the fiber

The transmission distance of the network cable is limited, and it cannot solve the long-distance data transmission. Therefore, the optical fiber can be used for long-distance transmission.

The optical fiber is divided into multimode and singlemode, and the distance of multimode transmission is farther than the network cable, but it is shorter than the single mode. In 10 mbps and 100 mbps Ethernet, multimode fiber can support a transmission distance of 2000 meters; in a 1GbpS Gigabit network, multimode fiber can support a transmission distance of 550 meters; therefore, multimode is now used less.

Single-mode fiber supports longer transmission distances than multimode fiber. In 100Mbps Ethernet to 1G Gigabit, single-mode fiber can support transmission distances over 5000m.

The single-mode optical module uses twice as many components as the multi-mode optical module, so the overall cost of the single-mode optical module is higher than that of the multi-mode optical module; the single-mode optical module can transmit distances of 150 to 200 km.

Therefore, for long-distance transmission can be solved with fiber optics, such as remote monitoring projects.

Third, HDMI cable

HDMI high-definition multimedia interface, generally used in high-definition displays, can be connected to hdmi display and display, and now many network boxes can also be connected to the TV through the cable to transmit audio and video signals.

The general HDMI signal transmission is less than 30 meters, so the distance of the general quality wire is about 15 meters.

So how is HDMI transmitted over long distances?

1, you can use the conversion extender

HDMI signal does not pass through other devices (transmit 120 meters)

HDMI signals are generally not directly transmitted to more than 30 meters with HDMI cables, and there are almost no HDMI finished lines over 30 meters in the market.

In this case, if the HDMI signal is simply transmitted to the display device, and the HDMI signal does not pass through other devices, we can use the method of extending the signal by the network cable, and use the HDMI cable extender to extend the signal, and the HDMI cable extender is divided into sending signals. Terminal (HDMI input, network cable output) and receiver (network cable input, HDMI output), can extend 100 meters (5 network cable), 120 meters (6 network cable).

2. Of course, if you need to transfer further, you can also use HDMI fiber extender.

There are many ways to extend HDMI. You can also use HDMI fiber optic cable, which can be used according to the actual situation.

Fourth, DVI

DVI is a digital video interface. The general DVI line can only effectively transmit signals about 5 meters. If it exceeds 5 meters, it will generate signal attenuation. This shortcoming greatly limits the popularity and application of DVI devices.

DVI-D can only receive digital signals; DVI-I can receive digital signals and analog signals at the same time, and the transmission distance is short, 7-15M.

Five, VGA cable

The VGA cable transmits an analog signal, which is a data transmission line that connects a computer graphics card to a display or a television to transmit information. It is responsible for outputting the corresponding image signal to the display, which is a bridge between the computer and the display. It has been widely used in the field of color display, but it is easy to attenuate, the transmission distance is short, and it is susceptible to interference. But its transmission distance is stronger than HDMI and DVI, and its 3+4/6VGA transmission distance is 20-40M.

Sixth, RS232 and RS485

1, RS232:

The RS232 transmission distance is limited, the maximum transmission distance standard is 15 meters, and only point-to-point communication, the transmission rate is 20kB / s.

2. RS485:

The RS485 wireless transmission distance is 1219 meters. The transmission rate is 10 Mbps, and the maximum communication distance can be achieved at a transmission rate of 100 Kb/s.

A dedicated cable with impedance matching and low attenuation can reach 1800 meters! More than 1200 meters, repeaters can be added (up to 8), so the transmission distance is close to 10Km.

Seven, usb line

Abbreviation for usb (Universal Serial Bus), an external bus standard that regulates the connection and communication between a computer and an external device. It is an interface technology applied in the PC field. The USB interface supports plug-and-play and hot-swap capabilities of the device.

The effective distance specified by the USB protocol is 5 meters, and a longer USB extension cable can be used, and the quality of the wire is better. The inferior USB extension cable can't reach 5 meters. Of course, if the usb line wants to transmit over long distances, it is also possible to use a extender.