Allen-Bradley 1747-L30B SLC 500 Processor Unit

Allen-Bradley 1747-L30B SLC 500 Processor Unit is a fixed-hardware CPU for the SLC 500 family that provides 30 I/O in a single module: 18 inputs and 12 triac outputs for AC load control. As a Series B fixed hardware processor, it mounts in a SLC 500 backplane and is powered from line voltage, typically 120/240 V AC, to support 18 AC inputs and 12 AC outputs. The 18 input channels are designed for direct connection to line-powered signals, while the 12 triac outputs are intended for switching AC loads such as small motors or relays under PLC control. Catalog listings and refurbishers consistently describe it as the 1747-L30B, often referenced as a 30‑I/O variant in the L30 family of SLC 500 processors, underscoring its role as a compact central controller with backplane expansion options.