Allen-Bradley 1747-L551 SLC 500 Processor Module

The Allen-Bradley 1747-L551 is a SLC 5/05 CPU module for the SLC 500 family, delivering 16K of program memory and 16,000 words of user memory to run ladder logic and store data. This processor is designed for rack-based SLC 500 backplanes and installs in Slot 0 of the chassis, with support for up to a 30-slot backplane configuration for I/O expansion. It provides RS-232 serial communications and Ethernet networking for programming and data exchange, aligning with common SLC 500 topologies. Key performance specs include a program scan time of about 0.9 ms and an I/O scan time around 0.225 ms, with capacity for up to 4,096 discrete inputs and 4,096 discrete outputs and up to 480 analog I/O paths depending on configuration. Typical use cases include automated control of industrial processes in manufacturing lines, packaging, and material handling, where a compact, ethernet-capable CPU in a 1747 backplane supports reliable, ladder-based control logic and integration with other Allen-Bradley I/O modules.