16channel photoelectric isolation inputs (NPN, lowlevel active). Each input is optically isolated to protect the controller from voltage spikes and EMI, improving reliability in noisy environments. 16channel outputs using ULN2803 NPN sink drivers. Robust switching for relays and small actuators with straightforward wiring and commonground compatibility. Six control modes: Open, Close, Momentary, Selflocking, Interlock, Delay. Provides flexible actuation schemes for doors, valves, and safety interlocks with predictable timing. RS485 remote control capability. 16 inputs can remotely drive 16 outputs on another board over RS485 (register configuration required), enabling distributed control across longer distances or multiple devices. Compatibility and integration. Designed for easy use with microcontrollers, PLCs, and automation systems; supports standard RS485 networks; compact module suitable for mounting in control cabinets and existing panels. Use scenarios 1) Factory automation: central controller activates multiple relays across a production line with isolated inputs protecting the controller. 2) Building or access control: door or gate actuation with momentary and interlock modes for safety and reliability. 3) Remote actuator control: drive valves or solenoids across a network of devices via RS485 for scalable automation.