[Danny Diaz]

The hardware engineers that designed the NI USB-6009 tell me there's already a small bit of protection in the 6009. To supplement this protection, they recommend the circuit I have attached - really it's just a matter of placing 2 diodes on each input, in the orientation specified (just make sure the Vcc for the circuit is the 12V power rail of the robot, NOT of the DAQ device). This allows a surge to drain into the power rail, where you'd most likely just momentarily charge the battery with the power surge. The Victor probably already has this type of protection, so placing the DAQ device inputs closer to the Victor will help if you're just super concerned.

For the diodes, just sizing the diode for the steady-state current of the motor should be sufficient.

Realize this does not work well if you're using a switched power supply, only a battery (thanks to the impedence of the battery!).

-Danny