The Duet 3 Expansion 1XD board provides step, direction and enable outputs to interface a Duet 3 system with a motor controller that takes those inputs. In addition it has a number of peripheral inputs and outputs for functions such as sensing driver alarms, temperature and controlling a brake and axis endstop. It connects to the Duet 3 CAN-FD bus using RJ11 connectors (same as the Duet 3 Mainboard 6HC, Duet 3 Mini 5+, Duet 3 Expansion 3HC, and the Duet 3 Tool Distribution Board). Multiple drivers can be daisy chained on the bus, with power (up to 48V) provided locally to the Duet 3 Expansion 1XD board. This allows for very large machines to be constructed without a significant wiring burden and signal integrity issues.