How to plot python x,y data in QtCharts

[Witc]

I want to plot data (from python) in QML Qt chart. Normally for passing data from python to QML I use Signals and Slot. e.g. for passing int variable I create signal in python class
signalInt = Signal(int, arguments=['value']) and later I call signalInt.emit(23)

then catching the value in QML
In QML file:

Connections {
            target: backend

            function onSignalInt(value) {
                tempVal = value;
            }

It works...

My questions:

1. How to pass array or list (I need pass X and Y values to plot) from python to QML
2. How to tell qtCharts to plot my X Y data?

I have these but it obviously does not work

Connections {
            target: backend

            function onSignaXYData(dataX,dataY) {
                plotDataX = dataX;
                plotDataY = dataY;
            }

 ChartView {
                title: "Line"
                anchors.fill: parent
                antialiasing: true

                ValueAxis{
                    id: axisX
                    min: 0
                    max: 200
                }

                ValueAxis{
                    id: axisY
                    min: 0
                    max: 150
                }


                LineSeries {
                    id: lineSeries1
                    name: "data"
                    axisX: axisX
                    axisY: axisY
                    XYSeries: plotDataX, plotDataY
                }
            }

Thank you very much!