I have added this conversion VI as an example here because I have searched for a LabVIEW converter but haven´t found one (maybe because it´s that simple to build one in LV). This function might help to transmit/receive data (Arrays of U8) by making use of the UDS palette within the Automotive Diagnostic Command Set LabVIEW Addon. DBLs could also be converted by adding little changes to the VI.
It´s a LabVIEW 2014 SP1 vi.
Example code from the Example Code Exchange in the NI Community is licensed with the MIT license.