Siemens SIMATIC S7-1500 System Manual page 85

Hardware identifier
STEP 7 automatically assigns a hardware identifier (HW identifier) to identify modules and
submodules. The HW identifier is used, for example, for diagnostics alarms or for
instructions, to identify the faulty module or the addressed module.
Figure 6-6
The "System constants" tab of a device includes all hardware identifiers and their names for
the selected module.
Figure 6-7
The default tag table contains the HW identifiers and name for all modules.
You can change the name of a hardware identifier in the properties of a module in "General"
You cannot change the value of a HW identifier.
Automation system
System Manual, 12/2014, A5E03461182-AC
Example of a Hardware identifier from STEP 7
Example of a default tag table from STEP 7
Configuring
6.1 Configuring the CPU
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