Allen-Bradley 1747-L543 SLC 500 Processor Unit

The Allen-Bradley 1747-L543 SLC 500 Processor Unit is a SLC 5/04 CPU for the SLC 500 modular PLC system, delivering 64K of user memory and support for up to 4,096 I/O points. This pre-owned processor (Rev. 3) includes an RS-232 serial port for programming andDiagnostics and a DH+ port for Data Highway Plus network communication with SLC‑500 I/O and other Rockwell devices. As part of the 1747 family, the L543 plugs into a 1747 backplane in a compatible chassis and runs ladder logic via RSLogix 500 for reliable, compact control. Typical applications include machine automation, packaging lines, conveyors, and other mid‑scale control tasks where solid processing and straightforward connectivity are important. The unit is supplied with a programming key, aligning with legacy installations that rely on authentic Allen‑Bradley hardware for consistent performance.