Allen-Bradley 1745-R1 Relay Board

Allen-Bradley 1745-R1 Relay Board is a replacement PC relay board designed for use with the SLC 100 processor family. As a drop-in replacement, it supplies the relay outputs the SLC 100 uses to switch external devices and control field loads, helping maintain ongoing operation when the original relay board is no longer available. The part is documented in distributor listings as a replacement relay board for the SLC 100 processor and is noted by some sources as discontinued by the manufacturer on April 30, 2014, with current availability generally coming from surplus or third-party suppliers. In practice, technicians install the 1745-R1 within legacy AB Rockwell Automation control panels that still rely on the SLC 100 platform, using it to preserve existing wiring and I/O logic without migrating to newer hardware. This makes the 1745-R1 a common option for extending the life of older automation systems in manufacturing, packaging, and process environments where discrete relay control remains a valid method for switching loads, alarms, or signaling devices. Because this is a legacy module, buyers typically verify compatibility with their exact SLC-100 chassis revision and ensure the replacement matches the original relay count and terminal configuration before installation.