Hello,
The problem is that the 6514 is only supported by NI-DAQmx as you can see
here. Ony traditional DAQ support DAQ OPC which would allow you to use the 6514 through OPC.
There are other DIO boards that are supported in traditional as you can
see on the page linked above(The ones that have a "T" underneath). If
using DAQ OPC is a must for your application, I would suggest
purchasing one board supported in Traditional NI-DAQ.
SergesL