The Mitsubishi RS-485 Communication Expansion Board, model FX2N-485-BD, is a dedicated option module designed for the FX2N series of programmable logic controllers (PLCs). This board enables RS-485 communication capabilities, allowing the PLC to engage in serial data exchange with other devices such as inverters, HMIs, sensors, and other PLCs. One of its key advantages is that it does not consume any DC24V power from the PLC system, making it energy-efficient and easy to integrate without affecting the system's power budget. Additionally, the FX2N-485-BD does not occupy any input or output points, preserving all I/O resources for actual process control. This makes it an ideal solution for applications requiring network communication without sacrificing I/O capacity. The board supports standard RS-485 communication protocols, including the Mitsubishi proprietary protocol (e.g., Computer Link) and N:N network connections, enabling flexible multi-drop or peer-to-peer networking over long distances with high noise immunity.