OPC Discovery Server Settings

A discovery server is an application that maintains a list of OPC UA servers available on the network. It provides mechanisms for clients to obtain a server application list. This considerably facilitates the configuration of clients that provide "find server/get endpoint" functionality, in particular if many servers are available or the exact server URL is not known.

In the 'Discovery server' category of the 'Server Settings' editor, you can specify whether a discovery server should be used for finding and connecting the server by its clients. After setting 'Discovery registration = enabled', further settings become visible where you can specify the discovery server URL as well as the registration interval.

After modifying these settings and writing them to the controller (as part of the PLCnext Engineer project), the controller (i.e., OPC UA server) generates the self-signed certificate when switching its state from Stop to Run and applies it.

The following fields are available.

Discovery registration

'disabled': the OPC UA server does not register at any discovery server.

'enabled': by registering the OPC UA server at the specified discovery server (see next entries), the server can be found as endpoint by clients.

Interval This field is only visible if 'Discovery registration = enabled'.
Specification of the time interval after which the OPC UA server has to register cyclically at the discovery server (alive signalization). If the interval elapses without a new registration of the OPC UA server, the OPC UA server is removed from the server list of the discovery server.
The value to be entered depends on the interval value specified for the discovery server.

Server url This field is only visible if 'Discovery registration = enabled'.
Replace the pre-configured sample URL opc.tcp://discovery.example.com:4840 accordingly.

Discovery registration	'disabled': the OPC UA server does not register at any discovery server. 'enabled': by registering the OPC UA server at the specified discovery server (see next entries), the server can be found as endpoint by clients.
Interval	This field is only visible if 'Discovery registration = enabled'. Specification of the time interval after which the OPC UA server has to register cyclically at the discovery server (alive signalization). If the interval elapses without a new registration of the OPC UA server, the OPC UA server is removed from the server list of the discovery server. The value to be entered depends on the interval value specified for the discovery server.
Server url	This field is only visible if 'Discovery registration = enabled'. Replace the pre-configured sample URL opc.tcp://discovery.example.com:4840 accordingly.