Allen-Bradley 1784-KT SLC 500 PLC I/O Module System

Allen-Bradley 1784-KT is a legacy Data Highway Plus (DH+) interface card designed for IBM PC/AT‑class computers to connect with DH/DH+ networks used by SLC 500 systems. As an ISA bus card, it plugs into a PC to provide DH+ communications with remote I/O and PLC devices in Allen‑Bradley SLC 500 environments, enabling programming, diagnostics, and data access from a PC host. The 1784‑KT family is documented in Rockwell literature; the 1784‑TD031 technical data notes CMOS‑based design and related considerations, while published manuals such as 1784‑UM001 cover integration and usage with DH+ networks. This hardware historically served as a bridge between legacy PCs and SLC 500 I/O networks, supporting data exchange with DH+ I/O modules and other DH+ devices in the system, though modern setups have migrated to newer interfaces. Rockwell’s support resources also reference replacement or alternative solutions for the 1784‑KT, underscoring its status as a legacy option within the SLC 500 ecosystem. In practice, the 1784‑KT enabled PC‑initiated access to DH+ I/O in SLC 500 installations, making it relevant for configurations that relied on PC‑based tooling for monitoring, data logging, or remote I/O communication on DH+ networks.