4channel NPN PNP signal converter that supports both NPN lowlevel and PNP level input signals. It offers broad compatibility with microcontrollers, PLCs, and industrial control systems, and features independent LED indicators for clear signal visibility. performance optocoupler isolation guarantees reliable signal conversion from 1*8V to 24V control signals, protecting sensitive equipment from voltage spikes and electrical noise in demanding industrial environments. Flexible output capability converts input signals to NPN output with a wide 3*3V–24V range and 200mA sink current per channel, making it suitable for driving relays, solenoids, and various industrial loads efficiently. Secure DIN rail installation with flameretardant plastic housing and 35mm DIN rail mounting. The compact 80*49*30mm board provides lasting spacesaving installation in control cabinets for diverse automation applications. Use scenarios Connecting a microcontroller with 3.3V/5V logic to 24V relays in an automation cabinet, with isolation to protect the controller. Interfacing PLC outputs with solenoid valves or actuators, enabling safe, reliable 24V switching while minimizing electrical noise transfer. Retrofitting mixedvoltage sensor networks in an industrial line, providing a consistent 1*8V to 24V control signal to a controller while maintaining channel isolation.