leo008,
I am not sure what you are asking for. OPC, TCP/IP, and Modbus are three different communications protocols. Are you trying to interface LabVIEW with this DAQ module? What communication method are you trying to use? If you need to communicate through OPC with LabVIEW (for free, as you mentioned), you can use DataSockets:
https://knowledge.ni.com/KnowledgeArticleDetails?id=kA03q000000x2C7CAI&l=en-US
For TCP/IP communication, check out this link:
https://www.ni.com/en/support/documentation/supplemental/06/basic-tcp-ip-communication-in-labview.ht...
We have a free Modbus Reference Library that you can use with LabVIEW as well:
https://forums.ni.com/t5/Reference-Design-Content/LabVIEW-Modbus-API/ta-p/3524019
Good Luck!
Drew T.
Camber Ridge, LLC.
