Siemens SINUMERIK 840D sl Configuration Manual page 161

Result
You can now address the selected variables in your PLC program and use the PUT [FB3] and
GET [FB2] blocks to write and read the variables.
SINUMERIK STEP 7 Toolbox V15.1
Configuration Manual, 12/2018, A5E46279635B AA
Tag selection with NC VAR selector
8.3 Adding a tag file (STL) in the TIA Portal
161