Specifying The Router For A Profinet Io Device - Siemens SIMATIC ET 200AL System Manual

Parameter assignment/addressing

3.4 Specifying the router for a PROFINET IO device

3.4 Specifying the router for a PROFINET IO device
Introduction
You always require a router (also referred to as a "Standard Gateway") when the PROFINET
device has to communicate with a node whose IP addresses lie outside the own IP subnet. If
the PROFINET device sends an IP packet to an IP address outside its own IP subnet, the IP
packet first goes to the configured router. The router in turn checks the IP address. If this lies
outside its own subnet, the router passes the IP packet on to the next router. The IP packet
is routed to the next router until it has reached the target address.
Like all S7-1500 CPUs, S7-1500 CPUs with several PROFINET interfaces provide the
possibility to configure the IP address of a router. However, there is the restriction that you
can only enter the IP address of a router at a PROFINET interface.
You cannot include an IP address of a router on the other PROFINET interfaces of the CPU.
IO devices that are connected to this PROFINET interface adopt this setting. Up to and
including STEP 7 V14 SP1, these IO devices did not have any possibility to reach devices in
a different IP subnet.
As of STEP 7 V15, you have the possibility to assign the address of a router for an IO device
independent of the setting of the IO controller. You can now, for example, set a router
address at the IO device in the following cases as well:
●
controller.
●
①
②
③
④
Figure 3-10
64
You have not set an IP address of a router for the interface of the associated IO
You have already set a router address for a different interface in the CPU.
Router R1 configured at PROFINET X1
If a router is configured at X1, you cannot configure a router at X2.
Because a router is configured at X1, the IO device adopts the IP address of the router R1.
The IO device can be reached from a different IP subnet.
As of STEP 7 V15, you set the IP address of the router R2 at the IO device irrespective of
the setting at the interface X2. The IO device can be reached from a different IP subnet.
Specifying the router for an IO device
PROFINET with STEP 7 V15
Function Manual, 12/2017, A5E03444486-AH