The Programmable Logic Control Unit (LCU) is designed to tackle the problems of frequent failures, difficult detection, and challenging maintenance in train relay control circuits, which are caused by the impact of complex environments, including aging, electromagnetic interference, vibration, temperature variations, and changes in various types of loads. By leveraging distributed programmable and safety control technologies based on "multiple-group redundancy" and contactless control and driving technologies based on signal acquisition and self-diagnosis, the LCU can completely replace traditional relays in train electrical control systems, directly controlling and driving train control signals and electrical equipment. This fundamentally overcomes the deficiencies of traditional contact-based logic control circuits, enhancing the safety and reliability of vehicle control, as well as the economy and convenience of operation, meeting the needs of improving the safe service performance of train control circuits under the influence of complex environments. It breaks the situation where the electrical status of traditional vehicles cannot be perceived, digitizes control and status information, and provides intelligent control and data support for smart vehicles. Its features include high integration, electrical digitalization, a maintenance-free design concept, intelligence, and simple graphical secondary development design.