Siemens SINUMERIK 880 Programming Manual page 196

05.91
Explanation for the example:
The program section from a cycle described in the above example shows how program
branches can be made up using IF-THEN-ELSE branches.
If the contents of register R58 in block N225 are less than or equal to the contents of register
R77, then the instruction given in the next line are executed.
Register R88 is loaded with 7 and register R95 with 12.45. However, if R58 is greater than
R77, then the program branches to block N230. In the line before block N230, there is,
however, an unconditional jump to block N250.
With the IF-THEN-ELSE branch in block N225, this means that either block N225 is executed
or the program section from block N230 to block N250.
In the lower example, the unconditional jump is missing so that either the instructions in block
N475 are followed or not. This program part can therefore be "skipped" with the IF-THEN-
ELSE branch @124.
Main group 1/subgroup 3: WHILE loop
@13x <Var> <Value> <Const>
The WHILE loop is a repetition instruction with scanning of the repetition conditions at the
beginning of the loop. The comparison operators correspond to those in the IF-THEN-
ELSE branch. As long as the comparison is satisfied, the next block is processed. An
absolute jump must be programmed at the end of the block with @100 <Const> to return
to scanning.
If the comparison has not been satisfied, a jump is made to the block defined in
<Const>, this block is usually located behind the block with the absolute jump.
Example:
N300 @131 R13 R27 K375 .
.
@100 K–300
N375 . . .
N300 @133 R13 R27 K375 .
.
@100 K–300
N375 . . .
© Siemens AG 1991 All Rights Reserved
SINUMERIK 880, (PG)
Continuation of the loop provided loop
condition R13 = R27 has been satisfied.
Continuation of the loop provided loop
condition R13 > R27 has been satisfied.
6ZB5 410-0HD02
11 Programming of Cycles
11.4 Program branches
11–9