S7 Routing - Siemens SIMATIC ET 200AL System Manual

11.2

S7 routing

Definition of S7 routing
S7 routing is the transfer of data beyond S7 subnet boundaries. You can send information
from a transmitter to a receiver across several s7 subnets. The gateway from one S7 subnet
to one or more other subnets is provided by the S7 router The S7 router is a device which has
interfaces to the respective S7 subnets. S7 routing is possible via various S7 subnets
(PROFINET/Industrial Ethernet and/or PROFIBUS).
Requirements for S7 routing
• All devices that can be reached in a network have been configured in a project in STEP 7
and downloaded.
• All devices involved in the S7 routing must receive routing information about the S7
subnets that can be reached through specific S7 routers. The devices obtain the routing
information by downloading the hardware configuration to the CPUs, since the CPUs play
the role of an S7 router.
In a topology with several consecutive S7 subnets, the following order must be kept to
when downloading: First download the hardware configuration to the CPU(s) directly
connected to the same S7 subnet as the PG/PC, then download one by one the CPUs of the
S7 subnets beyond this starting with the nearest S7 subnet through to the S7 subnet
furthest away.
• The PG/PC you want to use to establish a connection via a S7 router must be assigned to
the S7 subnet it is physically connected to. You can assign the PG/PC to a PG/PC in STEP 7
under Online & Diagnostics > Online accesses > Connection to interface/subnet.
• For S7 subnets of the type PROFIBUS: Either the CPU must be configured as DP master or,
if it is configured as a DP slave, the "Test, commissioning, routing" check box must be
selected in the properties of the DP interface of the DP slave.
• S7 routing for HMI connections is possible as of STEP 7 V13 SP1.
Note
Firewall and S7 routing
A firewall does not recognize the IP address of the sender during S7 routing when the sender
is located outside the S7 subnet adjacent to the firewall.
An overview of the devices that support the "S7 routing" function is provided in this FAQ
(https://support.industry.siemens.com/cs/ww/en/view/584459).
Communication
Function Manual, 05/2021, A5E03735815-AJ
Routing
11.2 S7 routing
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