Basic knowledge of LED display control card
The LED display control card is the core component of the LED display. The LED display controller is responsible for receiving the picture display information from the serial port of the computer, placing it in the frame memory, and generating the serial display data and scanning control timing required by the LED display according to the partition drive mode. It is divided into synchronous LED control cards. and asynchronous LED control card.
1. Synchronous LED control card:
Mainly used for real-time display of video, graphics, notifications, etc. Mainly used for indoor or outdoor full-color large-screen display. The working mode of the synchronous LED control card system to control the LED display is basically the same as that of the computer monitor. It maps the image on the computer monitor in real-time correspondingly at an update rate of at least 60 frames per second, usually with multi-gray color display capabilities. , can achieve the effect of multimedia advertising. Its main features are: real-time, rich expressiveness, complicated operation and high price. A synchronous LED display control card system generally consists of a sending card, a receiving card, and a DVI graphics card.
2. Asynchronous LED control card is also called offline LED control card or offline card:
Mainly used to display all kinds of text, symbols and graphics or animation. The screen display information is edited by the computer, and is pre-installed into the frame memory of the LED display screen through the RS232/485 serial port, and then displayed and played screen by screen, cyclically, and the display methods are colorful and varied. Its main features are: simple operation, low price and wide range of use. Simple asynchronous LED control card can only display digital clock, text and special characters. In addition to the functions of a simple control system, the most important feature of the graphic asynchronous LED control card is that it can control the content of the display screen in different areas.
With the rapid development of the LED industry, the demand space of the LED display control card market is also increasing, and the wireless LED control card can well meet the needs of the market for unified management and cluster transmission. For example, residential publicity LED screens, vehicle-mounted screens, government projects, mobile, telecommunications, and bank door front screens, batch installation, easy management, and maintenance-free status are the best choice for users.
Then users should pay attention to the following items in order to avoid unnecessary losses when using the control card:
1. Please keep the control card working in a dry and relatively stable environment. Excessive temperature, humidity, and dusty environment are extremely unfavorable to the control card.
2. In the case of no power failure, it is strictly forbidden to plug and unplug the serial port, so as to avoid damage to the serial port of the computer and the serial port of the control card due to improper operation.
3. It is strictly forbidden to adjust the input voltage of the control card when the system is working with electricity, so as to avoid damage to the computer serial port and the control card serial port due to improper adjustment and high voltage. The normal working voltage of the control card is 5V. When adjusting the power supply voltage, the control card should be removed, and a multimeter should be used to measure and adjust slowly.
4. It is strictly forbidden to short-circuit the grounding end of the control card with the display frame, otherwise, once static electricity accumulates on the display frame, it is very easy to damage the serial port of the computer and the serial port of the control card, resulting in unstable communication. on the display unit. Therefore, when the outdoor screen or the communication distance is long, it is recommended that the user must use a serial port isolator to avoid damage to the computer serial port and the control card serial port due to harsh environments such as ground loops, surges, inductive lightning strikes, and hot swapping.
5. It is necessary to ensure the correct connection between the control card and the computer serial port, so as to avoid damage to the control card serial port and the computer serial port due to incorrect input signals.
6. Do not connect the control card to the unit board. Directly lead to the switching power supply as much as possible, the voltage of the unit board is extremely unstable during the working process. It will cause the control card to be fast and slow, serious inability to communicate or the program to run away and needs to be repaired, especially the U-disk control card, which may not be able to read the disk or read the disk error when the voltage is unstable.
7. Indoors, the 16-scan unit board should not be connected to the whole screen for debugging. Many indoor single-color or double-color, or even full-color, and the control card is directly connected to the power supply in the uncommissioned state, which may burn out the line scan driver 4953 chip behind the unit board in a large area. . For debugging, please connect only one unit board for debugging, unplug the power supply after debugging, and then connect the control card.