Allen-Bradley 1747-L542 is a SLC 5/04 CPU for the SLC 500 family, delivering 32K of user memory (32 kilobytes) in a compact controller module. It provides a built-in RS-232 serial programming interface and a Data Highway Plus (DH+) port for networked communication with other controllers and devices. This 1747-L542 is designed for rack-based SLC 500 systems and is commonly used in discrete and process-control applications where legacy DH+ networks are present. Rockwell Automation lists the 1747-L542 as discontinued as of March 31, 2024, reflecting its status as a legacy hardware option within the SLC 500 lineage.
