OPC UA Client Application Operations in OpcCmd

Tutorial:

If you execute the commands listed in the tutorial below, you will get an overview of available client application operations.

1. At the OpcCmd> prompt, enter uaClient getService uaClientApplication, or shortened: uac gs uaca.
   The program responds with the name of the client application (""OPC Command-line Tool"), which will be used for registrations to GDS. If this is the first time the program is run, it also creates its self-signed client certificate.
   All following commands are entered at the uaClientApplication> prompt. You can enter -?, -h or --help (possibly preceded by the command name) at any time to obtain help for this prompt (or its commands).
2. In order to create application registration ibn the GDS, enter registerToGds opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer -eu appadmin:demo (registerToGds can be shortened to rtg). The argument to the command is the URL of the Global Discovery Server (GDS). The -eu option (shortened form of --EndpointUser) specifies the user name and password for user authentication to the GDS. The command argument and option is repeated in many commands further below, and they have the same meaning. When the operation is successful, the GDS assigns an application ID to the client application, and the OpcCmd utility displays this application ID to you. The application ID an OPC UA node ID for a node that represents the application inside the GDS.
3. In order to verify the registrations that exist inside the GDS for the client application, enter findGdsRegistrations opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer -eu appadmin:demo (findGdsRegistrations can be shortened to fgr). The command displays a list of registrations for this client application. There is normally just one registration, but in some cases there may be more. The list includes the application ID, application type (usually Client), application name, and the discovery URI (with servers).
4. You can obtain a new client certificate from the GDS by entering obtainNewCertificate opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer -eu appadmin:demo. When the command is successful, the certificate from the GDS (which serves as certification authority) is stored into the certificate store on the client side, and will be used by this client is its subsequent operations (be aware that this has the potential of affecting whether connection can be made to various servers by the client or not; further down in this tutorial, you will find how to revert this action).
   This is a multi-step operation, and it may take a considerable time to complete. The program displays progress messages as it performs the various steps. In some cases, a manual confirmation might be needed on the GDS side, before the GDS issues a certificate to the client; in such case, the command will not complete until somebody operating the GDS approves the certificate request. After the command is successfully completed, it displays the (main parameters of) the new client certificate.
5.  ?
6. refreshTrustLists opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer -eu appadmin:demo
7. unregisterFromGds opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer -eu appadmin:demo
8. removeInstanceCertificate
9. You can check the parameters of the client instance certificate by entering getInstanceCertificate, or shortened: gic.
10. If you want to force the application to generate a new self-signed client certificate, you can do so by entering removeInstanceCertificate, or shortened: ric. This might be useful e.g. for repeated testing against a GDS, if you have already received a client certificate from GDS (signed by a certificate authority), and want to revert to the initial state. At the next OPC UA operation, the application will generate a new self-signed certificate for itself, and use it for subsequent operations.