Siemens SIMATIC S5-100U System Manual page 195

S5-100U
Block End "BE"
The "BE" operation terminates a block. Data blocks do not need to be terminated. "BE" is always
the last statement in a block.
In structured programming, program scanning jumps back to the block where the call for the current
block was made.
Boolean logic operations cannot be continued in a higher-order block.
Example: Program block PB3 is terminated by the "BE" statement.
Program Sequence
OB1
JU PB3
Unconditional Block End "BEU"
The "BEU" operation causes a return within a block. However, jump operations can bypass the
"BEU" operation in function blocks (see sections 8.2.10 and 8.3.4).
Binary logic operations cannot be continued in a higher-order block.
Example: Scanning of function block FB21 is terminated regardless of the RLO.
Program Sequence
PB8
JC=
JU FB21
EWA 4NEB 812 6120-02b
STL
.
PB3
.
.
.
.
.
BE
BE
STL
.
FB21
.
.
.
JC=
BEU
.
.
BEU
.
.
BE
BE
STEP 5 Operations
Explanation
The "BE" statement terminates
program block PB3 and causes
program scanning to return to
organization block OB1.
Explanation
The "BEU" statement causes program
scanning to leave function block FB21
and return to program block PB8.
8-37