The DAQ-OPC Server is a fairly antiquated service that only exists in our Traditional DAQ driver, but installing the T-DAQ driver is what gives you the DAQ OPC functionality. However, upon the creation of DAQmx, the same functionality was expanded and improved up by using the Shared Variable Engine. DAQmx tasks and channel values are deployed to the Shared Variable Engine, and can be read by typical OPC Clients in the same way you would have with the DAQ-OPC Server. Below is an article that expands upon this, but to get this functionality then you should only need DAQmx installed on your system.
Using the LabVIEW Network-Published Shared Variable and OPC With NI-DAQmx:
http://www.ni.com/white-paper/3742/en/
The NI DAQmx and T-DAQ drivers cannot be installed at the same time, so if you need the old method that uses the DAQ-OPC Server, then you can only have the Traditional DAQ drivers installed on your system. However, since DAQmx does the same thing using the Shared Variable Engine, then there really isn't a reason to stick with the T-DAQ drivers.
Traditional NI-DAQ (Legacy) 7.5:
http://www.ni.com/download/traditional-ni-daq-legacy-7.5/4498/en/
NI-DAQmx download (9.8):
http://www.ni.com/download/ni-daqmx-9.8/4297/en/
Kelsey W.
National Instruments
Applications Engineer
