The Allen-Bradley 1747-L551 is a processor module from the Allen-Bradley SLC 500 and SLC 5/05 Programmable Logic Controller (PLC) series. This reliable and efficient processor supports the Allen-Bradley 1747-M13 memory module, providing up to 64K of backup memory capacity for program and data storage. The 1747-L551 processor module features built-in CMOS RAM with battery backup to ensure data retention during power loss. It has a maximum current capacity of 1 ampere at 5V DC and 0 amperes at 24V DC. Capable of supporting up to 32 simultaneous communication connections, the Allen-Bradley 1747-L551 delivers stable processing power, dependable communication, and flexible performance for industrial automation and process control applications.