Siemens SIMATIC S7-1500/ET 200MP System Manual page 333

Test and service functions
15.1 Test functions
Difference between modifying and forcing
The fundamental difference between the modifying and forcing functions consists in the
storage behavior:
• Modifying: Modifying of tags is an online function and is not stored in the CPU. You can
end modifying of tags in the watch table or force table or by terminating the online
connection.
• Forcing: A force job is written to the SIMATIC memory card and is retained after a POWER
OFF. The S7-1500 CPU displays an active force job with a corresponding symbol. You can
only end the forcing of peripheral inputs and peripheral outputs in the force table.
Testing with a PLC tag table
You can monitor the current data values of tags in the CPU directly in the PLC tag table. To do
so, open the PLC tag table and start the monitoring.
You also have the option of copying PLC tags to a watch table or force table so that you can
monitor, control or force them in the table.
Testing with a data block editor
The data block editor offers different options for monitoring and modifying tags. These
functions directly access the actual values of the tags in the online program. Actual values are
the current values of tags in the CPU work memory at any moment during program
execution. The following functions for monitoring and modifying are available in the
database editor.
• Monitor tags online
• Modify individual actual values
• Create a snapshot of the actual values
• Overwrite actual values with a snapshot
Note
Setting data values during commissioning
During plant commissioning, you often need to adjust data values to adapt the program to
local conditions.
To this end, the declaration table offers a few functions for data blocks.
Testing with the LED flash test
In many online dialogs, you can perform an LED flash test. This feature is useful if you are not
sure which device in the hardware configuration corresponds to the device currently selected
in the software.
If you click on the "Flash LED" button in STEP 7 under Online & diagnostics (online access), an
LED flashes on the device currently selected. The RUN/STOP, ERROR, and MAINT LEDs flash on
the CPU. The LEDs flash until you cancel the flash test.
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Automation system
System Manual, 01/2023, A5E03461182-AK