11.92
6 NC Programming
6.4 Programming for block search
6.4
Programming for block search
A trouble-free block search can only be ensured by programming using main blocks.
For milling machines, the NC block in which the tool change is initiated (L 06) must be defined
as a main block. After a block search, the paths are determined starting from this main block.
A main block is defined by a colon in front of the block number.
Example:
: 888
Main block
888
N777
Block
777
6.5
Programming the leader for reloading (SINUMERIK 880/880 GA2
and package 2 only)
The tools required in the part program are stored in the leader. They must be stored in the
order in which they are required. An H function can be assigned to the T word.
The use of the H function depends on the version (turning or milling version). In the milling
version, the H function is used to set the "Tool is required repeatedly" identification bit; for the
turning version, the H word provides information on the required turret location for the active
magazine.
Depending on the value of the R parameter, the leader can be skipped. In the following
example, the relevant R parameter is R 150. If this parameter has the value 0, the leader is
skipped.
NC program:
%100
R150=0
H . . .
@714
Decoding stop
@122 R 150 K0 K1
Jump to N1 if R150 = 0
Start FB "Load tool list"
T . . .
H . . . = 0
1st machining tool, required repeatedly
T . . .
2nd machining tool, required only once
:
:
:
:
T . . .
H . . . = 0
nth machining tool, required repeatedly
N1
H . . .
Terminate FB "Load tool list"
H . . .
Start FB "Generate exchange list"
!
!
v
Part program
The H values must be evaluated in the PLC program so that the necessary FBs can be start-
ed.
© Siemens AG 1991 All Rights Reserved 6FC5 197-0AA40-1BP1
6–3
SINUMERIK 840/880 (PJ)