What is the transmission distance of common cables

Cable transmission distance has always been the most frequent question asked by many weak current people, especially many friends who have just entered the weak current industry have little understanding of cable transmission distance. Below we will summarize the transmission distance of commonly used cables.

cable transmission distance

1. Network cable

The network cable is also a twisted pair, and there are different transmission distances according to different specifications of the network cable. The network cable is transmitting network signals. If it exceeds the distance that the network cable itself can bear, the signal will be attenuated. In severe cases, the network signal will be interrupted.

Category 5 and Category 6 are all 100 meters, and the normal oxygen-free copper Category 6 cable can reach about 120 meters. If the transmission distance is to be increased, a repeater can be installed between the two twisted pairs, and a maximum of 4 can be installed. repeater. If 4 repeaters are installed to connect 5 network segments, the maximum transmission distance can reach 500m.

2. Optical fiber

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

Optical fiber is divided into multi-mode and single-mode. The transmission distance of multi-mode is longer than that of network cable, but it is shorter than that of single-mode.

In 10mbps and 100mbps Ethernet, multimode fiber can support up to 2000 meters of transmission distance;

In the 1Gbps Gigabit network, the multimode fiber can support up to 550 meters of transmission distance;

So multi-mode is now used less.

Compared with multi-mode fiber, single-mode fiber can support longer transmission distance. From 100Mbps Ethernet to 1G Gigabit network, single-mode fiber can support more than 5000m transmission distance.

The devices used in single-mode optical modules are twice as many as multi-mode optical modules, so the overall cost of single-mode optical modules is higher than that of multi-mode optical modules; the transmission distance of single-mode optical modules can reach 150 to 200km.

Therefore, optical fiber can be used to solve long-distance transmission, such as remote monitoring projects.

3. HDMI cable

HDMI high-definition multimedia interface, generally used on high-definition monitors, can be connected to hdmi monitors and monitors. Now many network boxes can also be connected to TVs through connecting cables to transmit audio and video signals.

The general HDMI signal transmission is less than 30 meters, then the maximum transmission distance for the wire with general quality is about 15 meters.

So how does HDMI long-distance transmission?

1. You can use a conversion extender

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

HDMI signals generally cannot be directly transmitted to a distance of more than 30 meters with HDMI cables, and there are almost no finished HDMI cables of more than 30 meters on 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 with the network cable, and use the HDMI network cable extender to extend the signal. The HDMI network cable extender is divided into sending End (HDMI input, network cable output) and receiving end (network cable input, HDMI output), can be extended 100 meters (category 5 network cable), 120 meters (category 6 network cable).

2. Of course, if you need to transmit farther, you can also use HDMI fiber optic extender.

There are many ways to extend HDMI, and HDMI optical cable can also be used, which can be used according to the actual situation.

4. DVI

DVI is a digital video interface. A general DVI cable can only effectively transmit signals for about 5 meters. If it exceeds 5 meters, the signal will be attenuated. This shortcoming greatly limits the popularization and application of DVI equipment.

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.

5. VGA cable

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

6. RS232 and RS485

1. RS232:

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

2. RS485:

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

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

Seven, usb line

The abbreviation of usb (universal serial bus) is an external bus standard used to regulate the connection and communication between computers and external devices. It is an interface technology applied in the PC field. The USB interface supports plug-and-play and hot-plugging 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 cable is better. Inferior USB extension cables can't reach 5 meters. Of course, if the usb cable wants to transmit long distances, you can also use an extender.

The above is the whole content of the transmission distance of commonly used cables. For those who deal with cables every day, only by clearly understanding the use of cables can they be handy in the project. Hope the above can give you some help!