VEX Ultrasonic Sensor

[gr8dragon]

Hi,
I have been trying to use the vex ultrasonic sensor on the FRC robot and have had no success. I think the problem may be in the way i wired the sensor. I have both the wires going into the Digital I/O on the sidecar ports 3,1. I am using the WPILib ultrasonic class and can only manage to read zeros. Also on the driver station, under the diagnostics tab, the error messages box keeps saying assertion failed. Can some one help me get this sensor to read values or should i just order a "FRC" sensor.

Thanks