Displaying/canceling the access protection
You can password protect your program organizational units (POUs) in the PLC 828
programming tool. This prevents other users from accessing this part of the program. This
means that it is invisible to other users and is encrypted when it is downloaded.
A lock symbol is used to show a password-protected POU in the block overview and in the
Displaying cross references
You can display all the operands used in the PLC user project and their use in the list of
This list indicates in which networks an input, output, bit memory etc. is used.
The list of cross references contains the following information:
● Address in the network
● Context (command ID)
Symbolic and absolute address
You can choose between specification in absolute or symbolic address.
Elements for which there are no symbolic identifiers are automatically displayed with
Opening program blocks in the ladder diagram
From the cross references, you have the option of going directly to the location in the
program where the operand is used. The corresponding block is opened in window 1 or 2
and the cursor is set to the corresponding element.
Operating Manual, 03/2010, 6FC5398-7CP20-1BA0
The ladder diagram display (LAD) is opened.
Select the relevant program organizational unit (POU) in the overview
and press the "Program block" softkey.
Press the "Protection" softkey.
The "Protection" window appears.
Enter your password and press the "Accept" softkey.
Ladder Viewer and Ladder add-on (828D only)
19.18 Displaying/canceling the access protection