Constant opcua_core::prelude::constants::DEFAULT_OPC_UA_SERVER_PORT

pub const DEFAULT_OPC_UA_SERVER_PORT: u16 = 4840; // 4_840u16

Default OPC UA port number. Used by a discovery server. Other servers would normally run on a different port. So OPC UA for Rust does not use this nr by default but it is used implicitly in opc.tcp:// urls and elsewhere.