Technical data

Testing Using Program Status
21.4 Program Status of Data Blocks
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 473
21.4 Program Status of Data Blocks
From STEP 7 version 5 onwards, it is possible to observe a data block online in the data view. The
display can be activated either by an online data block or by an offline data block. In both cases,
the contents of the online data block in the programmable controller are displayed.
The data block must not be modified before the program status is started. If there is a structural
difference (declaration) between the online data block and the offline data block, the offline data
block can be downloaded to the programmable controller directly on request.
The data block must be located in the "data view," so that the online values can be displayed in the
"Actual Value" column. Only the part of the data block which is visible on the screen is updated.
While the status is active, you cannot switch to the declaration view.
While the update is in progress, a green bar is visible in the status bar and the operating mode is
displayed.
The values are issued in the format of the respective data type; the format cannot be changed.
After program status has been concluded, the "Actual Value" column displays again the contents
which were valid before the program status. It is not possible to transfer the updated online values
to the offline data block.
Updating data types:
All the elementary data types are updated in a shared DB, as well as in all the declarations
(in/out/in-out/stat) of an instance data block.
Some data types cannot be updated. When the program status is active, fields in the "Actual
Value" column which contain data which have not been updated are displayed with a gray
background.
• The complex data types DATE_AND_TIME and STRING are not updated.
• In the complex data types ARRAY, STRUCT, UDT, FB, and SFB, only those elements which
are elementary data types are updated.
• In the INOUT declaration of an instance data block only the pointer to the complex data type is
displayed, not the elements of the data type itself. The pointer is not updated.
• Parameter types are not updated
• See also:
• Introduction to Monitoring Variables.