OK managed to get the data sheet. It seems to say that the I option is available in either the 6V or the 12V version. So it doesn't look like you can use what you want.
Also it says the blue wire is used for PWM input, not the white one.
Make sure the black wire is connected to both the ground of your arduino and the ground of the power supply.
The white wire is used for the current loop input, you can't just connect that to the arduino.