When you say you want the National Instruments OPC server to communicate with the ION 7700 using ION's protocol, what do you mean?
If you already have an OPC server for the ION 7700, then you should be able to connect to that OPC Server directly from LabVIEW.
While the National Instruments OPC server does not directly support communication with the ION 7700, you may be able to communicate
with this instrument using a Modbus Object in the National Instrument's OPC Server. Does your ION 7700 support communication with the Modbus protocol?
Russell G.
NI Applications Engineering