Siemens SIMATIC STEP 7 V5.2 Getting Started page 53

Click the question marks and after entering a quotation mark address all the other
parameters of the function block using the corresponding symbolic names in the
pull-down list.
STEP 7 Getting Started
A5E00171228-01
Creating a Program with Function Blocks and Data Blocks
Double-click the data block Petrol.
This block is then entered
automatically in the input frame in
quotation marks.
The engine-specific input and output
variables (declaration "in" and "out")
are displayed in the FB "Engine."
A signal "PE_xxx" is assigned to
each of the variables for the petrol
engine.
5-17