Solution
1. You can use the
DataSocket Select URL VI to do this. The following two examples will let the user choose the URL of multiple tags and read them simultaneously:
2. This is possible, but it requires the Datalogging and Supervisory Control (DSC) Module. The whitepaper
Dynamic OPC Server Discovery and Connection explains in detail how this is done, and provides downloadable reference example VIs. In short, by using the DSC module, you can publish all OPC tags in the shared variable engine by using the NI Publish and Subscribe Protocol (NI-PSP). Once so, you can use shared variable engine property nodes to retrieve the OPC tags.