The Synchronous Sending Card ST40 is a sending device designed for LED display control. The card supports a total loading of 1.3 million pixels, with 650,000 pixels per network port, and supports a maximum width of 4096 pixels and a maximum height of 4096 pixels. For video input, it provides 1 HDMI/LVDS selectable video input and 1 AUDIO input. For output, it is equipped with 2 Gigabit network ports and supports arbitrary splicing in up, down, left and right arrangements. For communication and control, it provides 1 USB interface for communication, allowing multiple sending cards to be cascaded and controlled on the same PC. It supports upper-computer software monitoring of the sending card's operating parameters and status, and supports Gigabit network bit error rate detection. For display performance, it supports brightness and chromaticity pixel-by-pixel calibration, and supports data inspection with one-key inspection and data repair after replacing the receiving card on the large screen. The product is provided with third-party ilac-MRA, CNAS and CMA functional test reports.