How to connect from an output block to an input block in openmodelica?

Question

I have an openmodelica interface.

block InputInterfaceBlock

   CPSModel.ConnectionObjects.SocketConnection con =     CPSModel.ConnectionObjects.SocketConnection("/pathToSocket/rpcSocket");

  Modelica.Blocks.Interfaces.RealOutput y annotation(
    Placement(visible = true, transformation(origin = {194, 2}, extent = {{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {106, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));

 algorithm
   while true loop
    y := CPSModel.Functions.readFromSocket(con);
    print("Message from server : " + String(y) + "\n");
   end while;

  annotation(
     __OpenModelica_simulationFlags(jacobian = "coloredNumerical", s = "dassl", lv = "LOG_STATS"),
uses(Modelica(version = "3.2.2")),
Icon(graphics = {Text(origin = {4, -1}, extent = {{-62, 73}, {62, -73}}, textString = "Input\nInterface", fontName =            "DejaVu Sans Mono Bold")}));

   annotation(
     Placement(visible = true, transformation(origin = {-70, 70}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
end InputInterfaceBlock;

I have an interface block (InputInterfaceBlock) which reads from a socket which is defined in the path. I want this interface block to connect to another block (OutputInterfaceBlock).

block OutputInterfaceBlock

  CPSModel.ConnectionObjects.SocketConnection con = CPSModel.ConnectionObjects.SocketConnection("pathToModel/rpcSocket");

  Modelica.Blocks.Interfaces.RealInput y annotation(
    Placement(visible = true, transformation(origin = {194, 2}, extent = {{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {106, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));

algorithm
    print("Trying to send : " + String(y) + "\n");
        CPSModel.Functions.writeToSocket(con, y);
        print("Message send to server." + "\n");

annotation(
    __OpenModelica_simulationFlags(jacobian = "coloredNumerical", s = "dassl", lv = "LOG_STATS"),
uses(Modelica(version = "3.2.2")),
Icon(graphics = {Text(origin = {4, -1}, extent = {{-62, 73}, {62, -73}}, textString = "Output\nInterface", fontName = "DejaVu Sans Mono")}));
  annotation(
    Placement(visible = true, transformation(origin = {-70, 70}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
end OutputInterfaceBlock;

My model is as follows.

model MechatronicSystem

  CPSModel.Models.InputInterfaceBlock Input annotation(
      Placement(visible = true, transformation(origin = {-90, 8}, extent = {{-28, -28}, {28, 28}}, rotation = 0)));

  CPSModel.Models.OutputInterfaceBlock Output annotation(
      Placement(visible = true, transformation(origin = {72, 12}, extent = {{28, 28}, {-28, -28}}, rotation = 0)));

equation
  connect(Input.y, Output.y) annotation(
    Line(points = {{-60, 8}, {44, 8}, {44, 12}, {42, 12}}, color = {0, 0, 127}));
annotation(
      uses(Modelica(version = "3.2.2")));
end MechatronicSystem;

I can receive the data in the InputInterfaceBlock from the socket to the model, but when I try to send that data to OutputInterfaceBlock. It is not getting received in the OutputInterfaceBlock.

How can I fix it ?

Hans Olsson Hans Olsson · Accepted Answer · 2017-06-01T12:27:54

You are using a while true loop in InputInterfaceBlock, but the different algorithms in Modelica are not co-routines but normal algorithms.

You could replace that with when sample(0.1,0.1) then ... end when; or similarly, which will run the code every 0.1s seconds.

The while-loop causes the model should be stuck in InputInterfaceBlock and OutputInterfaceBlock not be called.

How to connect from an output block to an input block in openmodelica?

1 Answers