ABB PM554-RP: A compact powerhouse for distributed automation. The ABB PM554-RP Programmable Logic Controller (PLC) delivers a powerful punch in a small package, making it perfect for dispersed automation applications. Consider it the brains of your smaller control systems, efficiently handling logic and communication tasks. AC500-based: Takes advantage of the proven technology and versatility of the ABB AC500 platform.v128 kB RAM: Enough memory for your control applications and data. 8 digital inputs/6 digital outputs: Addresses critical I/O requirements immediately, with extension options available. RS485 and 2x option slots: Enables connectivity with a variety of devices and modules, increasing functionality.