LED display synchronous control card and asynchronous control work principle
The led display control card is divided into synchronous and asynchronous control cards. The synchronous control card is mainly applied to the full-color LED display. The asynchronous control card is mainly a simple single-and-two-color LED display. The former must have a computer to output data in order to work. The latter can work by simply importing the content directly with the u disk.
Display synchronous control card
Display synchronization control card, mainly used to display video, graphics, notifications, etc. in real time. Mainly used for indoor or outdoor full color large screen display. The display synchronization control system controls the display mode to be basically the same as the computer monitor. It maps the images on the computer monitor in real time with a refresh rate of at least 60 frames per second, usually with multi-gradation color display capability. Can achieve multimedia promotional advertising effects.
Display asynchronous control card
The display asynchronous control card is also called the display offline control system or the offline card. Mainly used to display a variety of text, symbols and graphics or animation. The screen display information is edited by the computer, and is pre-positioned into the frame memory of the display screen through the RS232/485 serial port, and then displayed on the screen by screen, and the display mode is colorful and varied. The display's simple asynchronous control system can only display digital clocks, text, and special characters. In addition to the function of the simple control system, the display graphic asynchronous control system has the biggest feature of controlling the display screen content by region. Support for analog clock display, countdown, picture, table and animation display. With timing switch, temperature control, humidity control and other functions.
Display control card features
The main features of the display synchronization control card are: real-time performance, rich expressiveness, complicated operation and high price.
The main features of the display asynchronous control card are: simple operation, low price and wide application range.
The principle of the display control card
Synchronous control card composition
The sending card displays the content to be displayed on the VGA display according to the specific format required by the led display screen and a certain broadcast order; on the other hand, the screen displayed on the VGA display is sent to the control board through the capture card, and the capture card is collected. Is the VGA used to display the interface card between the card and the LED screen. The receiving card is a video signal (control signal and data signal) transmitted from the receiving card, and the data in the video signal is separated by a bit plane, stored in an external buffer, and then read out and transmitted to the display driving screen.
Asynchronous control card
The asynchronous control card stores the display data edited by the computer in advance in the display control system. After the computer is turned off, it does not affect the normal display of the led display. Simply put, use a control card, use the computer to edit the content, or put the content on the control card with a USB flash drive, etc., then only one control card controls the display, no computer control is required.