When commercial complexes, transportation hubs and other scenes use multiple LED screens for linkage display, problems such as signal asynchrony and content confusion occur frequently. The cascade control system builds a "digital nerve center" for multi-screen collaboration through topological architecture design and protocol adaptation. The system is based on the master-slave control mode. It cascades multiple controllers into a tree network through network cables or optical fibers, so that the scattered LED screens form a unified display unit, solving the root cause of information confusion from the hardware bottom.

Before deployment, the "three elements" planning must be completed: draw a physical topology diagram according to the layout of the display screen to determine the location of the main controller and the signal transmission path; calculate the total number of pixels to ensure that the bandwidth of the main control device meets the 4K/8K signal transmission requirements; clarify the synchronization accuracy requirements of the application scenario, such as the stage performance needs to meet the ±1ms frame synchronization standard. When setting up the hardware, first connect the main controller to the core switch, and cascade the slave controllers through the RJ45 interface or the optical fiber interface. The length of each link must be controlled within 100 meters (network cable) or 20 kilometers (optical fiber) to avoid signal attenuation. After the equipment is connected, the underlying configuration needs to be performed: set the physical address and display parameters of each display screen through dedicated software, establish a three-level mapping relationship of "main controller - slave controller - display screen", and enable the clock synchronization module at the same time to ensure that the frame refresh frequency of all screens is consistent.

Three key tests need to be performed during the system debugging phase: in the signal cascade test, by sending a dynamic checkerboard pattern, check whether the seams of the cross-screen display are aligned; the synchronization test uses a high-speed camera to shoot multiple screens to confirm that the frame delay difference is less than 0.5 frames; the redundant backup test simulates the failure of the main controller to verify whether the slave controller can automatically switch to the main control mode. In a case of a convention and exhibition center, after deploying the cascade control system, 12 LED screens of different sizes achieved seamless splicing of 4K videos, the edge error was less than 1 pixel when scrolling text across the screen, and the system response delay was controlled within 8ms. From smart exhibition halls to city light shows, the standardized deployment of cascade control systems is making multiple LED screens become a whole, presenting an orderly visual experience in complex scenes.