Siemens SINUMERIK 840D sl Programming Manual page 763

Working without a T or D number
A standard T number and standard D number can be set per machine data,
which do not have to be reprogrammed and are effective after power on/reset.
Example: All machining is performed with the same grinding wheel.
The machine data can be used to set that the active tool remains for a reset (see "Free D
number assignment, cutting edge number (Page 497) ").
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
13.1 Grinding-specific tool monitoring in the part program (TMON, TMOF)
Grinding
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