Allen-Bradley 1771-KA Communication Adapter Module

The Allen-Bradley 1771-KA Communication Adapter Module is an interface card for PLC-2 Data Highway networks. It mounts in a 1771 I/O chassis and provides the Data Highway link that lets a PLC-2 processor communicate with other Data Highway devices. The KA enables peer-to-peer data exchange and remote I/O communication across the DH network, extending the reach of a PLC-2 installation beyond the local processor rack. In typical deployments, the KA connects the PLC-2 controller to Data Highway devices such as remote I/O racks, intelligent peripherals, and operator interface devices that reside on the same DH network, enabling status updates, data sharing, and coordinated control across a factory floor. The module is used as part of Allen-Bradley’s Data Highway communications family and relies on compatible PLC-2 hardware and cabling to form a functional DH network. As a dedicated communication adapter, the 1771-KA bridges the controller and the DH network, providing a stable interface for data exchange without requiring additional software or gateways.