Siemens SIMATIC ET 200AL, System Manual

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Parameter assignment/addressing
3.2 Device name and IP address
PROFINET with STEP 7
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Function Manual, 05/2021, A5E03444486-AL
3.2.1 Device name
Device names
Before an IO device can be addressed by an IO controller, it must have a device name. In
PROFINET, this method was selected because it is simpler to work with names than with
complex IP addresses.
The assignment of a device name for a specific IO device can be compared to setting the
PROFIBUS address of a DP slave.
In delivery state, an IO device does not have a device name. A device name must first be
assigned before an IO device can be addressed by an IO controller, for example, for
transferring configuration data during startup or for exchanging user data in cyclic mode. You
assign the device names to the IO device, for example, with the programming device / PC.
IO devices that have a slot for removable storage media provide the option of writing the
device name directly to the removable storage medium in the programming device.
When a device is replaced by a device without removable medium, the IO controller assigns
the device name based on topological configuration (see section Configuring topology
(Page 1)).
Structured device names
The device name is automatically assigned by default for PROFINET devices S7-1200,
S7-1500, ET 200MP, ET 200SP and ET 200AL when these are configured in STEP 7. The device
names are formed from the name of the CPU or the name of the interface module. For
devices with several PROFINET interfaces, the name of the interface is enhanced, for
example, "plc_1.profinet-interface_2" or "io-device_1".
You can structure the device names using DNS conventions.
These conventions are defined by "Internationalizing Domain Names in Applications (IDNA).
According to this, device names are written in lower case.
The "Domain Name System" (DNS) is a distributed database (
http://iana.org ), which manages
the name space on the Internet. To structure the names, you use the dot ("."). The hierarchy
is shown in ascending order from left to right.
...<Subdomain name>.<Domain name>.<Top-level domain name>
If the name is not DNS-compliant, the name will be converted by STEP 7, for example, to
"plcxb1.profinet-schnittstellexb2022c" or "io-devicexb15b32".