[sumo-user] Error while getting information from vehicle

["Muktadir R Chowdhury (mrchwdhr)" <mrchwdhr@xxxxxxxxxxx>]

I have the following client code:

#include <iostream>

#include <stdlib.h>

#include <string>

#include "TraCIAPI.h"

class Client : public TraCIAPI {

public:

    Client() {};

    ~Client() {};

};

int main(int argc, char* argv[]) {

    Client client;

    int order = atoi(argv[1]);

    client.connect("localhost", 47000);

    TraCIAPI::VehicleScope vehicleScope(client);

    while(true ) {

        client.simulationStep();

        libsumo::TraCIPosition pos = vehicleScope.getPosition(std::to_string(order));

        std::cout << pos.x << ", " << pos.y  << std::endl;

    }

    client.close();

}

I run sumo like this:             sudo sumo --remote-port 47000 -c map.sumocfg &

Then I run client program:   ./client 1

So the program should continuously print the position of vehicle with id 1. It is printing for some time, and after some time the program exiting by throwing the following error:

terminate called after throwing an instance of 'tcpip::SocketException'

  what():  .. Answered with error to command (164), [description: Vehicle '1' is not known]

Aborted (core dumped)

What might have caused this error?

Muktadir