LED displays are widely used in the leisure culture square, the bustling commercial base, commercial street, railway stations, subways, shopping malls, and other places. Because of its use in the field by the diversity, complexity, for stable audio and video signal transmission, reliable, fluency is also a higher demand. Single screen play about, or approach signal transmission using simulcast network LED occasions LED displays and other displays are also diversified, more common in the LED display signal into a wired signal transmission cable, GPRS, 3G, 4G wireless way to convey the wireless signal. LED display signaling that about you understand? Let Jiangsu brightly colored electron to tell you.

A, LED large screen signal transmission Category:

     1, the wireless transmission: rely mainly on the frequency of the radio signal to classify different jobs, such as long-wave, medium wave, short wave and microwave. Phone signal is a wireless access approach, now a lot of use of mobile phone GSM operating frequency at 900MHz. TV signal breed, the more, for example TV: General is the transmission of analog signals, digital TV is the transmission of digital signals; LED display signals are digital television signals on the satellite signals.

     2, cable transmission: can be divided into analog transmission, digital signal transmission, digital optical signal transmission.

Second, LED electronic display large-screen signal transfer project:

     In addition to signal attenuation, other factors affecting the signal transmitted is a signal reflection. Impedance and impedance mismatch is causing successive two main reasons for constituting the signal reflected RS-485 bus. Impedance mismatch, the impedance mismatch between the impedance of the first 485 chip and communication lines do not match. That gave rise to reflection because communication lines idle, all communication line signal mess, once these reflected signals trigger input 485 chip contrast, a fault will occur in the signal. Let usual solution is to A, B line RS-485 bus, plus the resistance of the bias resistor must then pulled up and down respectively, this can not predict prevent clutter signal. A series impedance, when the light is reflected from one medium into another medium caused similar. Signals the end of the transmission line impedance of the cable suddenly encountered little signal will cause the local reflection. This reflection eliminate the most common solution is at the end of a jumper cable characteristic impedance of the cable and the same size of the terminal resistor.

Third, how to ensure that large screen LED electronic display signal transmission process safety functions:

    We can develop simple robust RS-485 communication protocol, when communication distance is short, use of the environment disturb hour, one-way communication function to complete the project, but most of the use of the environment so this is not always ideal. Thus, to develop a comprehensive communication protocol is particularly important. The specific measures, the data sub-transfer, after each packet data plus header and trailer of the way the data package, during the end of frame leaving a byte as a check byte. Next crew after their accounts check bytes and PC transmission over the check bytes for comparison, giving PC announced instruction, in the end is just the beginning to send the packet data is then still issued the next packet data, Such a package and then send the next packet finished until finished stop. After such a check retransmission mechanism, we will be able to reduce the probability of error, so that the normal operation of the communication system.

    Always, the signal transmission process, followed by an increase in the interval weakened. Therefore, in order to ensure playback LED screen, LED display performance relative to other advertising to convey, and to select the LED display of the transmission medium is especially important.