Siemens S7-1200 System Manual page 772

Communication processor and Modbus TCP
12.6 Telecontrol and TeleService with the CP 1242-7
Direct communication between stations
Figure 12-5
In this configuration, two SIMATIC S7-1200 stations communicate directly with each other
using the CP 1242-7 via the GSM network. Each CP 1242-7 has a fixed IP address. The
relevant service of the GSM network provider must allow this.
TeleService via GPRS
In TeleService via GPRS, an engineering station on which STEP 7 is installed communicates
via the GSM network and the Internet with the CP 1242-7 in the S7-1200.
Since a firewall is normally closed for connection requests from the outside, a switching
station between the remote station and the engineering station is required. This switching
station can be a telecontrol server or, if there is no telecontrol server in the configuration, a
TeleService gateway.
TeleService with telecontrol server
The connection runs via the telecontrol server.
● The engineering station and telecontrol server are connected via the Intranet (LAN) or
Internet.
● The telecontrol server and remote station are connected via the Internet and via the GSM
network.
The engineering station and telecontrol server can also be the same computer; in other
words, STEP 7 and TCSB are installed on the same computer.
772
Direct communication between two S7-1200 stations
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG