Siemens SINUMERIK 840Di Function Manual page 1145

In the case of direction selection with special positioning input "Offset" > 0, a new setpoint
position is calculated from the setpoint and special positions and the number of magazine
locations according to the following formula:
New setpoint position = (setpoint pos. - (special pos. -1)) neg. modulo # locations
The new setpoint position corresponds to the location number at which the magazine must
be positioned so that the setpoint position requested by the user corresponds to the location
number of the special position. The directional optimization is active both with and without
special positioning.
The block must be called once with the appropriate parameter settings for each magazine.
Warning
The block may be called only in conjunction with tool management or after a DB 74 data
block has been set up as described below in the example. In this example there are two
magazines. The first magazine has 10 locations and the second has 12 locations. When
adapting to the real machine, you only need to change the data AnzMag, MagNo[.].
DATA_BLOCK DB 74
STRUCT
end_struct
BEGIN
END_DATA_BLOCK
Note
For further details on tool management (also with regard to PLC) refer to the Description of
Functions, Tool Management. Furthermore, PI services are provided for tool management
via the FB 4, FC 7 and FC 8 (see also the corresponding Sections in this documentation).
Power Line Basic PLC Program (P3)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
P: ARRAY[1 to 9] of DINT
w1: WORD ;
AnzMag: BYTE ;
res:BYTE;
MagNo: array [1 to 16] of struct //Byte 40
AnzPlatz:INT;
res1:BYTE;
res2:BYTE;
end_struct;
P[4]:=L#320;
AnzMag:=b#16#2;
MagNo[1].AnzPlatz:=10;
MagNo[2].AnzPlatz:=12;
//Absolutely essential
//Total number of magazines = 2
//Number of locations for magazine 1 = 10
//Number of locations for magazine 2 = 12
Detailed description
2.12 Block descriptions
2-233