Have you confirmed your wiring matches both the
Robot Power Distribution (with correct polarity) and
Robot Data Connectivity diagrams, paying particular attention to the power and signal wires to the digital sidecar?
Is the digital module on the cRIO in slot 4 (with 1 being the slot nearest the lights)?
Are the lights green on on your cRIO?
Does anything else on the digital sidecar work (PWMs, sensors, whatever)?