Block Call Operations - Siemens SIMATIC S5 Manual

STEP 5 Operations
3.1.8

Block Call Operations

Block call operations specify the sequence of a structured program. Table 3-8 provides an overview
of the block call operations. Examples follow the table.
Operation Operand
JU
JC
ID
OB
PB
FB
SB
C
G
ID
DB
BE
BEU
BEC
* Please note that certain OBs are assigned by the operating system.
** Data blocks DB 0 to DB 3 are reserved and may only be read (G DB operation illegal):
DB 0 Block address list
DB 1 Configuration DB ( 1.1.7)
3-32
Table 3-8. Overview of Block Call Operations
Jump unconditionally
Program scanning continues in a different block regardless of the
RLO.
The RLO is not affected.
Jump conditionally
Program scanning jumps to a different block when the RLO is "1".
Otherwise program scanning continues in the previous block.
The RLO is set to "1".
Parameter
0 to 255
0 to 255
0 to 255
0 to 255
Call a data block.
A data block is activated regardless of the RLO.
Program scanning is not interrupted.
The RLO is not affected.
Generate and delete a data block.
An area is set up in the RAM to store data regardless of the RLO.
Parameter
1 to 255
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.
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.
Method of representation: only STL possible
DB 2 Error DB, subunit A ( 5.4.2)
DB 3 Error DB, subunit B ( 5.4.2)
Meaning
*
**
S5-115F Manual
EWA 4NEB 811 6149-02