HEIDENHAIN TNC 320 User Manual page 247

Please note while programming:
Danger of collision!
Datums from a datum table are always and exclusively
referenced to the current datum (preset).
If you are using datum shifts with datum tables, then use
the SEL TABLE function to activate the desired datum table
from the NC program.
If you work without SEL TABLE, then you must activate the
desired datum table before the test run or the program
run. (This applies also to the programming graphics).
Use the file management to select the desired table for
a test run in the Test Run operating mode: The table
receives the status S.
Use the file management in a program run mode to
select the desired table for program run: The table
receives the status M.
The coordinate values from datum tables are only effective
with absolute coordinate values.
New lines can only be inserted at the end of the table.
If you create datum tables, the file name has to start with
a letter.
HEIDENHAIN TNC 320 247