Siemens SINUMERIK 840D sl Programming Manual page 538

Additional functions
13.2 Check scope of NC language present (STRINGIS)
Valid NC addresses without address extension with the fixed value of 400
NC addressed D, F, G, H, R and L, M, N, O, P, S, T are valid. Then
400
Example of programmable auxiliary function T
T is defined as auxiliary function
400 = STRINGIS("T")
0 = STRINGIS("T3")
13-6
D as tool correction, cutting edge number (D function)
F as feed (F function)
G is defined as G code (not the path condition in this case)
H stands for auxiliary function (H function)
R is defined as system parameter and
L stands for sub-routine call-up, M stands for additional
function, N stands for sub-block,
O is free for extensions,
P stands for number of program executions,
S stands for spindle speed (S function),
T stands for tool number (T function).
and can always be programmed.
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
;Return value without address
;extension
;Return value with address extension
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