Step 1 : Check the source the tag i.e. where this tag will be collecting data.
Step 2 : Check if instrument tag field has correct information. .e.g If you are using OPC server then check instrument tag attribute on the tag. This should match with OPC server item.id for the interface to start collecting data.
Step 3: Use OPC client tool and check if the item.id on OPC server has the data. This step will provide more information if it is something to do with configuration of the tag or OPC item doesn't exists or some issue with name configured on the tag.
Retrieving data ...