The Local Discovery Server(LDS) is an OPC UA Serverthat implements the Discovery Service Setdefined in OPC 10000-4. If an LDS is installed on a machine it shall use one or more of the well-known addresses defined in Table 57.

Table 57– Well known addresses for Local Discovery Servers

Transport Mapping	URL	Notes
OPC UA TCP	opc.tcp://localhost:4840/UADiscovery
OPC UA WebSockets	opc.wss://localhost:443/UADiscovery
OPC UA HTTPS	https://localhost:443/UADiscovery

OPC UA applications that make use of the LDS shall allow administrators to change the well-known addresses used within a system.

The Endpoint used by Serversto register with the LDS shall be the base address with the path “/registration” appended to it (e.g. http://localhost/UADiscovery/registration). OPC UA Serversshall allow administrators to configure the address to use for registration.

Each OPC UA Serverapplication implements the Discovery Service Set. If the OPC UA Serverrequires a different address for this Endpoint, it shall create the address by appending the path “/discovery” to its base address.