For more information on how to map axis to these drivers (for example if you want to use external drivers for the X,Y and Z axis) see using external drivers
The pinout is shown below, all 5 driver channels provide differential signales (ENA-,ENA+, DIR_,DIR+, STEP-, STEP+)
A 50 way IDC cable is required to connect the expansion breakout board to a second generation Duet board (Wifi or Ethernet), note it is not compatible with first generation Duet boards (0.6, 0.8.5).
Two wires are required for each balanced signal, it is designed to connect to external drivers that take a balanced input , for example the Leadshine DM556 drivers.
The board has 4 M4 clearance holes for mounting: