Allen-Bradley 1747-L541 SLC 500 Programmable Logic Controller

The Allen-Bradley 1747-L541 SLC 5/04 CPU Processor is a 16K-memory controller in the SLC 500 family, designed for DH+ and RS-232 communication on a 30-slot SLC 500 backplane, making it a compact, stackable option for small to mid-size automation panels. It provides 16K words of user memory and can control up to 4,096 I/O points, with a program scan time of about 0.9 ms per keyword and an I/O scan time of roughly 0.225 ms, enabling responsive control of sequencing and discrete I/O tasks. The processor includes built-in DH+ and RS-232 ports for DH network connectivity and programming with RSLogix 500, and it uses flash-based backup memory to retain data when power is removed. Rockwell Automation discontinued the 1747-L541 as of December 31, 2021, reflecting its status as a legacy, non-Ethernet SLC 500 CPU. This CPU is best suited for legacy automation setups that rely on RSLogix 500 tooling and DH+ networks, delivering a straightforward, cost-effective solution for simple machine control, conveyor sequencing, and batch-style processes in older systems.