Siemens SIMATIC S7-400 Operating Instructions Manual page 57

– Best possible procedure
● Anonymous access
– Allow read access
– Allow write access
Note
No connection with disabled options
When the Security functions are enabled and for the option "Anonymous access" neither
read nor write access is enabled, with an anonymous login, no connection is established.
It is also not possible to browse the address space.
In this case, a connection can only be established with a user name and password.
"Certificate validation"
In this tab you set the options for checking the certificates of the communications partner.
You can set the options for the UA client and UA server function of the CP separately.
● Checking the certificate
The CP always checks the certificate of the communications partner.
If the partner certificate is invalid or is not trustworthy, communication is aborted.
● No strict certificate validation
If the option is enabled, the CP allows communication in the following situations:
– The IP address of the communications partner is not identical to the IP address in its
– The use stored in the certificate (OPC UA client/server) differs from the function (OPC
– The current time on the CP is outside the period of validity of the partner certificate.
CP 443-1 OPC UA
Operating Instructions, 01/2017, C79000-G8976-C427-02
Depending on the settings on the communications partner (client), the CP selects the
procedure with the the highest possible security. This may be:
- Sign
or
- Sign and encrypt
The CP allows read access to the data of its OPC UA server.
The CP allows write access to the data of its OPC UA server.
certificate.
Note: The OPC UA server does not check the IP address of the communications
partner (client).
UA client/server) of the communications partner.
Configuration and operation
4.7 Configuration of the CP in STEP 7 V5
57