Technical data

Testing with the Variable Table
20.5 Establishing a Connection to the CPU
Programming with STEP 7
456 Manual, 05/2010, A5E02789666-01
20.5 Establishing a Connection to the CPU
In order to be able to monitor or modify the variables you entered in your current variable table
(VAT), you must establish a connection to the appropriate CPU. It is possible to link each variable
table with a different CPU.
Displaying an Online Connection
If an online connection exists, the term "ONLINE" in the title bar of the variable table window
indicates this fact. The status bar displays the operating states "RUN", "STOP",
"DISCONNECTED" or "CONNECTED", depending on the CPU.
Establishing an Online Connection to the CPU
If an online connection to the required CPU does not exist, use the menu command PLC >
Connect To > ... to define a connection to the required CPU so that variables can be monitored or
modified.
Interrupting the Online Connection to the CPU
Using the menu command PLC > Disconnect you interrupt the connection between the variable
table and the CPU.
Note
If you created an unnamed variable table with the menu command Table > New, you can establish a
connection to the last configured CPU configured if it is defined.