Programming Actions and Conditions
S7-GRAPH for S7-300/400 Programming Sequential Control Systems
C79000-G7076-C526-01
7-23
Rules for Entering FBD Elements
When entering FBD elements, keep to the following rules:
•
All elements and branches must be connected together.
•
Each branch in an FBD network must contain at least one FBD element.
Modes for Inserting FBD Elements
There are two editing modes available for inserting FBD elements:
•
Insert > Direct In this mode, you first select the position in the sequencer at
which you want to insert an element and then select the element to be inserted.
•
Insert > Drag and Drop In this mode, you first select the element you want to
insert and then select the position at which the element will be inserted using
the mouse pointer. This mode is particularly suitable when you want to insert
the same element at more than one position in the sequencer.
Entering Addresses
There are two ways of entering addresses:
•
Click the placeholder "??.?" of the required text field. Then enter an absolute or
symbolic address (for example I1.0, "limit_switch"). You can use both the
German mnemonics (E, A) and the English mnemonics (I, O) for addresses. Set
the mnemonics you require in the SIMATIC Manager.
•
Select the address and then select an absolute or symbolic address from the
drop-down list box (for example I1.0, "Limit switch"). The address is then
entered.
Changing Over Between Ladder Logic and FBD
In S7-Graph, you can program conditions in one of two programming languages: In
ladder diagram (LAD) or in function block diagram (FBD). You can display the
conditions in LAD or in FBD at any time. To toggle the display, simply select the
appropriate menu command: View > LAD or View > FBD.
