Allen‑Bradley 1747‑L543 is a SLC 500 5/04 programmable logic controller with 64K of user memory. It provides a DF1-compatible RS‑232 serial port (Channel 0) for programming and data communication plus a DH+ port (Channel 1) for Data Highway Plus networking at up to 230.4 kbps. This legacy controller supports standard SLC‑500 applications in small to mid‑sized automation tasks, delivering reliable discrete logic, timing, and sequencing within the 1747 family. As of March 31, 2024, Rockwell Automation discontinued the SLC 5/04 64K controllers, including the 1747‑L543, and they are no longer sold new by the manufacturer.
