For stepper motors, the Caterpillar board does not drive the motor directly. Instead, it outputs 5 V control signals to an external stepper driver (such as a DM860I or TB6600), which handles the high-current motor supply. Many stepper drivers accept opto-isolated ENA+/ENA-, PUL+/PUL-, and DIR+/DIR- inputs referenced to 5V as supplied by the Caterpillar.

External stepper driver wiring diagram
External stepper driver wiring

Tested drivers

  • DM860I—up to 7.2 A, suitable for larger NEMA 34 motors
  • TB6600—up to 4.5 A, common choice for NEMA 23 motors