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Entry type: FAQ, Entry ID: 22257781, Entry date: 11/18/2005

How do you use WinCC flexible to configure communication between an operator panel and an S7 station via S7 routing?

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If all the stations within a programmable logic controller are not connected to the same bus (subnetwork), these stations will not be directly contactable online. In order to establish a connection between these devices, there must be a router connected between them. A SIMATIC station can act as a router if it has suitable interfaces to the different subnetworks. The modules with communications capability (CPUs or CPs), which are intended to create gateways between the subnetworks, must support routing.
Refer to a component's technical documentation to establish whether it supports routing. Alternatively, open the component's object properties in NetPro or in HW Config. The "General" tab contains a brief description of the properties.
You can find information about which modules possess routing capability in Entry ID: 584459


  • All stations must be networked in NetPro/HW Config, subject to the same requirements as with transfer via S7 routing.
  • In order to establish an S7 routing connection, all the communication partners within a STEP 7 project must be configured and loaded.

Fig. 01

In Fig. 01 a routing connection has been established between the SIMATIC HMI station(1) and the SIMATIC 300 programmable logic controller. The SIMATIC 400 programmable logic controller acts as a router. This type of routing connection can be established directly in integrated projects. For this purpose, a connection is set up in the SIMATIC HMI station, and the SIMATIC 300 PLC is selected directly as the connection partner. The routing connection is detected automatically by the system.
The connection properties in WinCC flexible show that it is a routing connection.

Fig. 02

You can find detailed explanations in the user manual (Entry ID 18796010) and in the online help for WinCC flexible.


  • An S7 connection, configured via S7 routing, occupies an additional connection resource on a SIMATIC station which is used as a router. Make sure that this SIMATIC station has adequate connection resources. If this station's connection resources are inadequate, there is a possibility that an S7 connection may not be set up to / through this station. In this case, you will need to use a more high-performance SIMATIC station or change the configuration.
  • If there is any change to the network configuration of a station in the STEP 7 project (NetPro / HW Config), all the stations in the project will have to be reloaded.

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