Allen-Bradley 1746-SDN Serial Interface Module

Allen-Bradley 1746-SDN Serial Interface Module is a legacy SLC 500 accessory that adds a dedicated serial communications interface to a 1746 I/O backplane. It is designed to plug into an SLC 500 modular chassis and work with the 1746 backplane to enable data exchange between the processor and serial devices. The module is used to connect serial peripherals or terminals to the SLC 500 controller, supporting the standard Serial communications path within the 1746 ecosystem. In typical installations it sits alongside other 1746 I/O modules, drawing power from the backplane and sharing the same timing and addressing conventions as the rest of the rack. The 1746-SDN leverages the SLC 500 software toolchain for configuration and data handling, allowing the processor to place serialized data into its I/O image for communication with external devices. For engineers maintaining legacy lines, this module provides a familiar path for integrating serial equipment with a Rockwell Automation control system. As a historical module, always verify compatibility with your specific chassis, processor, and firmware before planning a replacement or upgrade.