Thanks, that clarifies some things, I though that Node.start would spawn a new node, but that must mean I’ve only converted my current node to be distributed using three different names.

I was able to solve the issue by initializing three iex-interfaces using a batch-script:

defmodule SupervisorsTest do
  use ExUnit.Case
  import TCP_Driver
  import Poller
  doctest Poller
  @tag timeout: :infinity
  @tcp_ip {10,0,0,68}


  def nodename port do
    String.to_atom("OrderHandler_" <> to_string(port) <> "@10.0.0.68")
  end
  test "Pinger" do

    #There is a bug with the first initialized node
    #which causes a connection error. initializing a dummy solved it.
    spawn fn -> Node.start :dummynode@localhost end
    #init_ports_start_nodes_servers()

    port1 = to_string(Enum.random(3000..3500))
    port2 = to_string(Enum.random(3000..3500))
    port3 = to_string(Enum.random(3000..3500))

    spawn fn -> System.cmd("run.bat", [port1, port2, port3]) end

    :timer.sleep(3000)
    spawn fn -> System.cmd("kill_elevator_servers.bat", []) end
    spawn fn -> System.cmd("kill_iex.bat", []) end
    spawn fn -> System.cmd("kill_cmd.bat", []) end
    :timer.sleep(100000000)
  end



  def start_supervisors node, tcp_port do
    Node.spawn(node, fn -> Supervisors.init(%{address: {10,0,0,68},port: tcp_port}) end)
  end

end

And some simple cmd-commands. Startup:

start iex --name "OrderHandler_%1@10.0.0.68" -S mix
start iex --name "OrderHandler_%2@10.0.0.68" -S mix
start iex --name "OrderHandler_%3@10.0.0.68" -S mix

start ../SimElevatorServer.exe --port %1
start ../SimElevatorServer.exe --port %2
start ../SimElevatorServer.exe --port %3

Shutdown:

Taskkill /F /IM cmd.exe

Taskkill /IM SimElevatorServer.exe

Taskkill /F /IM erl.exe

This feels like a nasty way of controlling my nodes for testing, but it floats my boat.