Controlling AD5142 digital Potentiometer using NI8452

[Özgür88]

Hi, 

i try to control two AD5142 with a NI USB 8452. I have the following schematic of my DUT: 

However, the VI doesnt turn back any error. I also checked all the connections from NI 8452 to the Potentiometer. Does anyone has experiences with programming digital Potentiometers over a I2C-Connection with LabVIEW? You can find the data sheet and the VI in the attachement. 

Thanks a lot in advance and kind regards
Özgür