The AT0421X Input Device is a professional signal input module for collecting and transmitting analog and digital signals in electrical control systems, widely used in industrial control and intelligent monitoring. It adopts XBUS 2-wire communication, featuring simple wiring, low power consumption and strong anti-interference ability, which reduces installation difficulty and ensures stable signal transmission. It supports 4~20mA signal or passive switch signal input, compatible with various sensors and detection devices. With DC24V/200mA active output voltage, it provides reliable power support for connected input devices. Adopting 35mm DIN rail mounting, it's easy to install and integrate into existing electrical control cabinets. Suitable for (-10~+60)°C, <95%RH (no condensation) and (86~106)kPa environments, it maintains stable performance, serving as a key component for signal acquisition in intelligent control systems.