On the RPi, you need to ensure that I2C is enabled. Open a terminal on RPi, type "sudo raspi-config", go to Advanced Options and enable I2C. You can check that it is enabled by finding the config.txt file in "/boot" and checking for the line "dt_param=i2c_arm=on". Note that with the LabVIEW LINX I2C VI's, this is channel 1.