procedure AddNode(OPCClient: TdOPCDAClient);
var
NodeString : string;
Value : string;
IdentifierType: string;
NamespaceIndex: integer;
begin
Value := 'Triangle1'; // String value
IdentifierType := 's'; // value is string
NamespaceIndex := 5; // given namespace
NodeString := format('ns=%d;%s=%s',[NamespaceIndex,IdentifierType,Value);
// result is ns=5;s=Triangle1// and this is the way how you has to define NodeIds if you work with the dOPCDAClient component
OPCClient.OPCGroups[0].OPCItems.AddItem(NodeString);
ShowMessage(NodeString)
end;