Authentication

The TwinCAT OPC UA Client supports the use of different IdentityTokens to authenticate to an OPC UA Server.

• Anonymous
• Username/Password
• User certificate

The following screenshots are taken with the TwinCAT OPC UA I/O Client. All of the functions described are also supported when using the PLCOpen function blocks.

Anonymous

This type of authentication enables the TwinCAT OPC UA Client to establish a connection to the server application without specifying a user identity. Below you will find an example screenshot from the TwinCAT OPC UA I/O Client.

Username/Password

This type of authentication uses a username/password combination to authenticate the TwinCAT OPC UA Client to the server application. Below you will find an example screenshot from the TwinCAT OPC UA I/O Client.

User certificate

With this type of authentication, the TwinCAT OPC UA Client uses a certificate to authenticate itself to the server application. The handling of user certificates on the server side is identical to the use of certificates on the transport layer, i.e. the server must trust the (user) certificate before the client can successfully authenticate itself to the server with the certificate. Below you will find an example screenshot from the TwinCAT OPC UA I/O Client.