Technical data

Testing with the Variable Table
20.7 Modifying Variables
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 459
20.7 Modifying Variables
20.7.1 Introduction to Modifying Variables
The following methods are available to you for modifying variables:
• Activate the Modify function with the menu command Variable > Modify. The user program
applies the modify values for the selected variables from the variable table in accordance with
the trigger point and trigger frequency set. If you set the trigger frequency "Every cycle," you
can toggle the Modify function off again with the menu command Variable > Modify.
• You can update the values of the selected variables once and immediately using the menu
command Variable > Activate Modify Values.
The functions Force and Enable Peripheral Output (PQ) provide other possibilities.
When Modifying, Note:
• Only those addresses that were visible in the variable table when you started modifying are
modified.
If you decrease the size of the visible area of the variable table once you have started
modifying, addresses may be modified that are no longer visible.
If the visible area of the variable table is made larger, there may be addresses visible that are
not modified.
• Modifying cannot be undone (for example, with Edit > Undo).
!
Danger
Changing the variable values while a process is running can lead to serious damage to property or
personnel if errors occur in the function or in the program.
Make sure that no dangerous situations can occur before you execute the "Modify" function.
Aborting "Modifying" with ESC
If you press ESC while the "Modifying" function is in process, the function is aborted without a
query.