Not used labview, but on Kepware you can configure the tags on the kepware i.e. device1.Channel1 then a name "register_1" then the address (for ex if it was mitsi it would be D0001).
then if labview is a good bit of software you could browse the opc server & import the tags.
Kep doesn't require you to fill in the tags, instead you can create the tags in labview & providing you have the correct settings/opc link it should work.
best thing to do is set up opc comms, configure a tag in your opc
then use an opc client (some opc servers come with one for testing).
it should tell you if comms are working.
No knowing what plc/opc server you are using I cannot help anty further.