Siemens SIMATIC S5-100U, System Manual

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S5-100U STEP 5 Operations
8.1.8 Block Call Operations
Block call operations specify the sequence of a structured program. Table 8-8 provides an overview
of the block call operations. Examples follow the table.
Table 8-8. Overview of Block Call Operations
Operation Meaning
Jump unconditionally
Program scanning continues in a different block regardless of the
RLO.
The RLO is not affected.
Operand
JU
JC Jump conditionally
Program scanning jumps to a different block when the RLO is “1”.
Otherwise program scanning continues in the same block.
The RLO is set to “1”.
Parameter CPU 100 CPU 102 CPU 103
0 to 63 0 to 63 0 to 255
0 to 63 0 to 63 0 to 255
0 to 63 0 to 63 0 to 255
0 to 255
ID
OB
PB
FB
SB
C
BE Block end
The current block is terminated regardless of the RLO.
Program scanning continues in the block in which the call originated.
The RLO is “carried along” but not affected. BE is always the last
statement in a block.
BEU
BEC
Block end, unconditional
The current block is terminated regardless of the RLO.
Program scanning continues in the block in which the call originated.
The RLO is “carried along” but not affected.
Block end, conditional
When the RLO is “1”, the current block is terminated.
Program scanning continues in the block in which the call originated.
During the block change, the RLO remains “1”.
If the RLO is “0”, the operation is not executed.
The RLO is set to “1” and linear program scanning continues.
Call a data block
A data block is activated regardless of the RLO.
Program scanning is not interrupted.
The RLO is not affected.
Parameter CPU 100 CPU 102 CPU 103
2 to 63** 2 to 63** 2 to 255**
ID
DB
G Generate and delete a data block*
An area is set up in the RAM to store data regardless of the RLO.
*
The length of the DB must be loaded into ACCU 1 before execution of the operation. A length of 0
makes the DB invalid.
**
Data blocks DB0 and DB1 are reserved for special functions.
EWA 4NEB 812 6120-02b
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