Configuration and operation   
4.6 Security configuration(CP 1543SP-1) 
  CP 1542SP-1, CP 1542SP-1 IRC, CP 1543SP-1 
88  Operating Instructions, 01/2017, C79000-G8976-C426-03 
 
Creating a VPN tunnel for S7 communication between stations 
Requirements 
To allow a VPN tunnel to be created for S7 communication between two S7 stations or 
between an S7 station and an engineering station with a security CP (for example CP 1628), 
the following requirements must be met: 
●  The two stations have been configured. 
●  The CPs in both stations must support the security functions. 
●  The Ethernet interfaces of the two stations are located in the same subnet. 
 
Note 
Communication also possible via an IP router 
Communication between the two stations is also possible via an IP router. To use this 
communications path, however, you need to make furth
er settings. 
To create a VPN tunnel, you need to work through the following steps: 
1.  Creating a security user 
If the security user has already been created: Log on as a user. 
2.  Select the "Activate security features" check box 
3.  Creating the VPN group and assigning security modules 
4.  Configure the properties of the VPN group 
5.  Configure local VPN properties of the two CPs 
You will find a detailed description of the individual steps in the following paragraphs of this 
section. 
To create a VPN tunnel, you require appropriate configuration rights. To activate the security 
functions, you need to create at least one security user. 
1.  In the local security settings of the CP, click the "User login" button. 
Result: A new window opens. 
2.  Enter the user name, password and confirmation of the password. 
3.  Click the "Logon" button. 
You have created a new security user. The security functions are now available to you. 
With all further logons, log on as user.