rt-sim-training-client/static/workertest/passsimulation/passer.js

var i=0;
var update = null;
function timedCount(){

  onmessage = (e) => {


    if(e.data == "on"){

      update = setInterval("passerupdate()", 200);
    }

    if(e.data == "off"){
      clearInterval(update);
    }
}


}
function passerupdate(){

  postMessage("up");
}

timedCount();