There is a PCI card available that works with DAQ OPC, in this case the E-series product line would apply. Many of the PCI-6040E type cards have counters. However, at this stage of development I would recommend for serious consideration using LabVIEW and NI-DAQ. Lookout is a great program for communicating with OPC items. However, for basic to advanced data acquisition, LabVIEW is the optimized solution. All other ways will require more development time.
Regards,
Robert Jackson
Application Engineer