Siemens SIMATIC STEP 7 V5.2 Getting Started page 31

Programming an OR Instruction in Statement List
STEP 7 Getting Started
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Symbols are indicated in red if, for example, they do not exist in the symbol table, or
if there is a syntax error.
You can also insert the symbolic name directly from the symbol table. Click the ??.?
sign and then the menu command Insert > Symbol. Scroll through the pull-down list
until you reach the corresponding name and select it. The symbolic name is added
automatically.
Creating a Program in OB1
In the same way, complete the AND
instruction as shown.
You have now programmed a
complete AND instruction. Save the
block if there are no more symbols
shown in red.
Select Network 1.
Insert a new network and select the
input area again.
Enter an O (OR) and the symbolic
name "Key_3" (in the same way as for
the AND instruction).
Complete the OR instruction and save
it.
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