S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
791
Error codes
C
C.1
Timestamp mismatch
This warning message indicates that the timestamps for the project do not match the
timestamps for the program in the PLC. This may indicate that the programs are different, in
which case it would be dangerous to continue the current operation. However, the programs
might be functionally identical and still have different timestamps.
What actions modify the program timestamps?
Each program contains two distinct timestamps; the "Created" timestamp and the "Last
Modified" timestamp. The created timestamp is set when the project is created by the New
Project option. The Created timestamp is not affected by any user edits or program
compilation.
The Last Modified timestamp is used to indicate when the user last modified the program.
There are many conditions that cause the Last Modified timestamp to be set:
1.
An edit of instructions or operands in the program block editor.
2.
Adding, deleting, or modifying a variable or global symbol.
3.
Adding or deleting a POU.
4.
Compiling the program block.
5.
Downloading the program block (this automatically compiles the program block and
therefore sets the last modified timestamp).
Note that although all of these actions will cause the last modified timestamp to be set, this
does not necessarily mean that the programs are different. For this reason, STEP 7-
Micro/WIN SMART provides the "Compare" option, to allow you to determine whether the
programs are really different
How do I tell if the programs are really different?
You can choose to compare the program block in the PLC with the project's program block
by clicking the "Compare" button. The results of this comparison allow you to determine
whether to continue the status operation.
How do I synchronize timestamps?
Downloading a new project to the PLC synchronizes the timestamps, which allows you to run
status.