Siemens Simatic S7-300 Technical Data Manual page 42

Communication
3.2 Communication services
Routing: Example of a TeleService application
The figure below shows the example of an application for remote maintenance of an
S7 station using a PG. The connection to other subnets is here established via modem
connection.
The lower section of the figure shows how to configure this in STEP 7.
Real installation
Configuration in STEP 7
3-14
PG
Modem
PG
Subnet 1 (e.g. MPI)
e.g. 31xC-2DP
DP master
TeleService
adapter
(e.g. PROFIBUS DP)
Modem
Subnet 1 (e.g. MPI)
e.g. CPU 31xC-2 DP
DP master
Subnet 2 (e.g. PROFIBUS DP)
e.g. 31xC-2DP
DP slave
Subnet 2
e.g. CPU 31xC-2 DP
DP slave
CPU 31xC and CPU 31x, Technical data
Manual, Edition 08/2004, A5E00105475-05