TagNames Parameter
By default, the Historian REST service provides support to read samples for multiple tags.
Multiple tag names are separated by semicolons (;). For example,
"tagname1;tagname2;tagname3".
https://<historianservername>:8443/historian-rest-api
/v1/datapoints/currentvalue?tagNames=tagName1;tagname2;tagname3
https://RestTestsNode/historian-rest-api/v1/datapoints/currentvalue?tagNames=TAG01;TAG02
Encode the semicolon as %3B
if using the URI format, as the semicolon is also a valid character for a Historian name, and the web service parses the tag names incorrectly if a tag name contains a semicolon.