Algorithm 2. REST-based OPC UA Middleware Module Development Algorithm.

Input: OPC UA Binary Data, User Query Request, and Telegram Commands.

Output: Request URL to the web and cloud platforms. Notify for Telegram commands.

01:  function ConnectServer()

02:    try client = Client.Connect(ServerURL)

03:        if (client) then break;

04:    except pass

05:  function MakeReq (Platform, Address, Path as arguments)

06:    Get the root nodes as Query = client.get_root_node().get_children()

07:    for (i = 0; len(Query.get_children(i)); i++) do

08:        if (client.get_object_node().get_children(i) in Query) then

09:              Name =Query.get_children()[i].get_browser_name()

10:              Value =Query.get_children()[i].get_value(); Concatenate1= Name+Value;

11:              ClientBuilder += “$” + ServerObject(i) + “*” + Concatenate1

12:              CloudBuilder += Concatenate2; PCloudBuilder += Concatenate3

13:        end if

14:        if (Platform == ”web”) then

15:              ReqURL = Address + “Path?” + ClientBuilder

16:        elif (Platform == ”ThingsSentral”) then

17:              ReqURL = Address + “Path?” + CloudBuilder

18:        elif (Platform == ”PCloud”) then

19:              ReqURL = Address + “Path?” + PCloudBuilder

20:    end for

21:    try Req = Get(ReqURL) do

22:        if (Req.Status == 200) then break;

23:    except pass

24:  function StartTelegramWebHook()

25:    while (Message available in Telegram server) do

26:        Parse the message and store in chat_id, UserName, command variable.

27:    end while

28:    if (command is valid) then

29:        Call associated function for the corresponding command request.

30:        Bot.sendMessage(chat_id, Response)

31:    end if

Begin

32:  Start a thread calling ConnectServer() function to connect with OPC UA server.

33:  Call MakeReq (web, localhost, OPC) to send OPC UA credentials to the web.

34:  MakeReq(ThingsSentral, thingssentral.io, postlong) to send in ThingsSentralTM.

35:  Call MakeReq(Pcloud, Address, update) to send credentials to the cloud.

36:  Start a thread calling StartTelegramWebHook() to run Telegram Bot.

Finish