Siemens Sinumerik 840D sl Programming Manual page 95

<jump
destination>:
IF:
Note
Jump markers (labels)
Jump markers (labels) are always located at the beginning of a block. If a program number
exists, the jump marker is located immediately after the block number.
The following rules apply when naming jump markers:
• Number of characters:
– At least 2
– A maximum of 32
• Permitted characters include:
– Letters
– Numbers
– Underscore symbols
• The first two characters must be letters or underscores.
• The name of the jump marker is followed by a colon (":").
Supplementary conditions
• The jump destination can only be a block with jump marker or block number, that is
located within the program.
• A jump instruction without jump condition must be programmed in a separate block. This
restriction does not apply to jump instructions with jump conditions. In this case, several
jump instructions can be formulated in a block.
• For programs with jump instructions without jump conditions, the end of the program M2/
M30 doesn't necessarily have to be be at the end of the program.
Job planning
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
Jump destination parameter
Possible data include:
<jump marker>: Jump destination is the jump marker (label) set
in the program with a user-defined name:
<jump marker>:
<block number>: Jump destination is main block or sub-block
number (e.g.: 200, N300)
STRING type Variable jump destination. The variable stands
variable: for a jump marker or a block number.
Keyword to formulate the jump condition.
The jump condition permits all comparison and logical operations
(result: TRUE or FALSE). The program jump is executed if the result of
this operation is TRUE.
Flexible NC programming
1.10 Program jumps and branches
95