First of all, thank you dswaine for you reply. It provided help.
Since my first post things have evolved to a point where I can give simple boolean orders to the PLC, which then inserts pre-defined attributes to the ACH550-01 motor/frequency converter. The motor runs and there is a OPC server opening the PLC registry to LabVIEW via datasocket connection.
Now I am in a need of advice on how to write hex-values in labVIEW to let say address: PQW 258. I think I need something like slider which converts the values from 0-100 % to 0-4000hex and then writes this value to OPC-address. Would anyone have an example on how to do this?