The Allen-Bradley 1746-A4 SLC 500 four-slot rack backplane assembly is a four-slot modular chassis that provides the backplane interconnect for an SLC 500 expansion rack. It accommodates the CPU in one slot and up to three 1746 I/O modules in the remaining slots, with all cards linked through the backplane to form the system data bus. As part of the SLC 500 family, the 1746-A4 supports standard 1746-series CPUs and I/O modules designed for Rockwell Automation's SLC 500 modular system. This backplane assembly enables compact configurations for small to mid-range automation tasks while preserving compatibility with 1746-series cards.
