Data Blocks - Siemens SIMATIC S5-100U System Manual

Introduction to STEP 5
PB 3
: JU FB5
NAME : EXAMPLE
X1 : I 0.0
X2 : F 1.3
X3 : Q 1.0
.
.
: A I 0.1
: JC FB5
NAME : EXAMPLE
X1 : I 0.3
X2 : I 0.2
X3 : Q 1.0
7.3.5

Data Blocks

Data blocks (DB) store data to be processed in a program.
The following data types are permissible:
• Bit pattern (representation of controlled system states)
• Hexadecimal, binary or decimal numbers (times, results of arithmetic operations)
• Alphanumeric characters (ASCII message texts)
7-16
FB 5
NAME : EXAMPLE
DES:
DES:
DES:
Parameter list
for first call
Formal operands
Actual operands
Parameter list
for second call
Formal operands
Figure 7-6. Programming a Function Block
X1 I BI
X2 I BI
X3 Q BI
: A = X1
: A = X2
: = = X3
A
: BE A
=
A
A
=
S5-100U
Executed
program
First call
I 0.0
F 1.3
Q 1.0
Second call
I 0.3
I 0.2
Q 1.0
EWA 4NEB 812 6120-02b