Siemens SINUMERIK 840D sl Function Manual page 1818

Detailed Description
2.2 Flat D number structure
Example 2
MD22550 = 0
T1
T2
T3
D777
Note
The tool change and the assignment of a D compensation to an actual tool are not the
responsibility of NCK.
Indirect indexed programming
Dn or D=n
Meaning: Select the D number entered at position n (=1, ...) in the D number table. 9) is
entered. Although this syntax is identical to the conventional one, it activates the
compensation block for the D number determined for index n internally.
Example of indirect D programming sequence:
MD20270 $MC_CUTTING_EDGE_DEFAULT (Basic setting of tool cutting edge without
programming) is = 0.
MD22550 $MC_TOOL_CHANGE_MODE (new tool compensation with M function) is = 0.
Spindle No. 2 is not the master spindle
Part program
T4
X1
...
D1
D=$P_DNO[2]
30
No wait, D777 is activated,
T3 = programmed and active tool in display
D777 = programmed and active compensation
Action
Tool change command: NCK outputs the value 4 as T auxiliary function. PLC
evaluates it and provides the associated absolute D numbers in the VDI. The
PLC only does this if the address extension received is the number of the
master spindle. A simple communication protocol allows the NCK to detect
whether the associated D numbers are available for the subsequent
programmed D.
The NCK feed is synchronized with the main run, checks whether the new D
numbers are present in the VDI (and waits if necessary) and accepts the
desired (absolute) D number at position 1 (D1), e.g., the number 4711.The NCK
now determines the compensation block 4711 and calculates the geometry.
The NC copies the entire content of the D number table to the VDI interface
(each time a tool change command is detected).
Contents correspond to the programming of D2 (for indirect programming)
Basic logic functions: Tool Offset (W1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0