Siemens SIMATIC S7-1500 System Manual page 91

Configuring
7.1 Address assignment
Hardware identifier
In addition to the I/O addresses, a hardware identifier (Hardware identifier), which is used to
identify the module, is assigned automatically by STEP 7. Such a Hardware identifier is also
assigned to submodules.
The Hardware identifier consists of an integer and is output at diagnostics alarms by the
system. This identifies the faulty module or the functional unit.
Figure 7-6
You also use the Hardware identifier for a series of instructions in order to identify the
module to which the instruction should be applied.
The HW identifier is assigned automatically by STEP 7 and cannot be changed by the user.
The Hardware identifier is assigned automatically when components are inserted in the
device or network view, and entered in the "Default tag table" of the PLC tags. A name is
also assigned automatically for the Hardware identifier. These entries in the "Default tag
table" of the PLC tags cannot be changed either.
Figure 7-7
90
Example of a Hardware identifier from STEP 7
Example of a default tag table from STEP 7
S7-1500 Automation System
System Manual, 02/2014, A5E03461182-AB