Number of tags read from Tag Query at a time

[former_member235359]

SAP MII 12.0

I have Tag Group in OPC server in which there are more than 200 tags that I have to read at a time.

In SAP MII I am able to select only 128 tags at a time. Is this a limitation or is there any other way to read the all the tags in that group at a time. I tried passing the parameters for group(path) and mode(current) but in the resultset i am able to view only 128 tags.

If someone can guide how to go about this.

Thanks

Gaurav

[jcgood25 · Accepted solution]

Using BLS you can use a TagList query, passing the same Group property to get the list of named tags in the OPC group. Then bust up the list into the chuncks of 128 or less and request them by name. You should be able to pass a comma separated list of up to 128 tags into the TagName property for a tag query. Then merge the data results from each query into the necessary format.

The 128 tag limit is a configured limit so prevent unbounded queries (similar to query templates having a rowcount property), it also provides a boundary to the array of tags for saving the query template as well as javascripting with setTagName(x,'Tag');