[DmitryR]

Вот скрин

function Timer2(){
      xhr.open("GET", "content.bin?r=" + Math.random(), true);
      xhr.responseType = "arraybuffer";
      xhr.onload = function (oEvent) {
        var uint16Array = new Uint16Array(this.response);
        var uint16Array1 = new Uint16Array(256);
        var uint16Array2 = new Uint16Array(256);
        for(var i = 0; i < 256; i++)
        {
          uint16Array1[i] = uint16Array[i];
          //uint16Array2[i] = uint16Array[i+256];  
          uint16Array2[i] = uint16Array[i];     
        }
        myChart.data.datasets[0].data = uint16Array1;
        myChart.data.datasets[1].data = uint16Array2;
        myChart.update(); 
        //console.log("Chart update");

        //myChart.data.datasets[0].data = uint16Array;
        //myChart.data.datasets[1].data = uint16Array;
        //myChart.update();             
      }
      xhr.send(null);
      idTimer2 = setTimeout(Timer2, 1000);
    }