Allen-Bradley 1746-A4 SLC 500 4-Slot Rack Assembly

Allen-Bradley 1746-A4 is a four-slot expansion rack for the SLC 500 modular I/O system, enabling you to add up to four 1746 I/O modules to an existing chassis without altering the primary rack. As part of the SLC 500 family, this 4-slot chassis provides a separate expansion backplane that ties into your main rack via 1746 rack interconnects, commonly using expansion cables such as 1746-C7 or 1746-C9 to bridge the gap between racks. The 1746-A4 is designed for expansion in industrial control setups where additional I/O capacity is required while keeping the processor and core I/O in the main chassis. In typical configurations, the 1746-A4 sits adjacent to the main SLC rack, accepts up to four individual 1746 I/O modules, and relies on the backplane to deliver common power and signaling to those modules through the extension cables. This chassis is specifically marketed for SLC 500 systems and forms a standard option when planning scalable modular I/O in legacy Rockwell Automation installations.