Siemens SIMATIC STEP 7 V5.2 Getting Started page 34

Creating a Program in OB1
4-12
Symbols are indicated in red if, for example, they do not exist in the symbol table, or
if there is a syntax error.
Click on the ??.? sign and enter the
symbolic name "Key_1" (in quotation
marks). Alternatively, you can also
select the name from the displayed
pull-down list.
Confirm with Enter.
Enter the symbolic name "Key_2" for
the second input.
Enter the name "Green_Light" for the
assignment.
You have now programmed a
complete AND function.
If there are no more symbols shown in
red, you can save the block.
STEP 7 Getting Started
A5E00171228-01