Siemens SIMATIC S7-1500 System Manual page 229

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
Not e
S et ting data v alues during c ommissioning
During commissioning of a plant, data values have to be frequently adjusted in order to
optimally adapt the program to the general operating conditions on site. The declaration
table for data blocks offers some functions for this purpose.
Testing with the LED flash test
In many online dialogs, you can perform an LED flash test. This function is useful, for
example, when you are not sure which device in the hardware configuration corresponds to
the station currently selected in the software.
When you click the "Flash LED" button, an LED flashes at the currently selected station. On
the CPU, the following LEDs flash: RUN/STOP LED, ERROR LED and MAINT LED. The
LEDs flash until you cancel the flash test.
Testing with a trace function
The trace function is used to record the CPU tags, depending on the settable trigger
conditions. Tags are, for example, drive parameters or system and user tags of a CPU. The
CPU saves the recordings. You can display and evaluate the recordings, if necessary, with
STEP 7 or via the Web server.
The trace function can be called from the CPU's folder in the project tree, under the name
"Traces".
In connection with trace functions, also note the following FAQ on the Internet
(http://www.siemens.com/automation/service&support
Automation system
System Manual, 09/2016, A5E03461182-AD
Test functions and fault resolution
14.1 Test functions
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