mobileFX WebKitX CEF3 ActiveX 4.x
WebKitXCEF3Lib ActiveX Control / WebKitXCEF3 Object / HMI_VALUE_001 Property
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    HMI_VALUE_001 Property
    In This Topic

    HMI_VALUE_xxx properties are bi-directional I/O channels intended for passing sensor data directly to HTML/JavaScript for HMI/HUD displays, or for forwarding control signals from HTML to the underlying Automation or IoT controller software. The property is intended to be used by Rockwell FactoryTalk. To use WebKitX in HMI environments you must set Enable_HMI_IO to True.

    Property type
    Read-write property
    Visual Basic
    Public Property HMI_VALUE_001 As String

    Available in version 4.x.

    HMI_VALUE_xxx properties are bi-directional I/O channels intended for passing sensor data directly to HTML/JavaScript for HMI/HUD displays, or for forwarding control signals from HTML to the underlying Automation or IoT controller software.

    Creating HMI Dash Boards with HTML5

    With WebKitX you can create HMI Dash Boards by forwarding sensor data to HTML and JavaScript for rendering. The input signals are latched and the clock frequency is controlled by Settings.hmi_input_clock_frequency_hz which defaults to 2Hz. This means that input signal values are buffered by WebKitX and are flushed to HTML/JavaScript every 500 milliseconds. If no input signals are registered since last flush then no emission takes place. You can disable the input latch and pass the input signal values at real-time by setting the Settings.hmi_enable_input_clock to False.



    It is important to understand that input signals travel over Interprocess Communication (IPC) from the ActiveX to Chromium Engine which are the processed by JavaScript and eventually alter the DOM of the HTML HMI user interface. This is a time-consuming process and therefore you must limit the hmi_input_clock_frequency between 0.1 Hz and 60 Hz. The upper limit of 60 Hz is equivalent to screen refresh rate of 60 fps (frames per second) or screen refresh every 16.7 milliseconds. Even though Chromium supports 60 fps rendering for Hardware Accelerated Graphics (WebGL), you should not push beyond 60 Hz.

    When the Automation and IoT controller software sets a HMI_VALUE property, the property is transferred to window.HMI_VALUE[index] JavaScript Array. WebKitX also tries to find in your HTML HMI/HUD user interface JavaScript code the function OnHMIDataSignal(index, data) and call it. HMI HTML developers are required to add this callback function in their code in order to receive the forwarded input signals.

    Handling HMI_VALUE changes with JavaScript Callback function
    Copy Code
    function OnHMIDataSignal(index, sensorData)
       sensorData = parseInt(sensorData);
       let item = $('.gauge')[index-1];
       let gauge = $(item).dxCircularGauge('instance');
       let gaugeElement = $(gauge._$element[0]);
       gaugeElement.find('.dxg-title text').last().html(sensorData + ' °C');


    Creating HMI Control Boards with HTML5

    The following feature is experimental and depends on the internal implementation of the OLE container used by the Automation and IoT software and particularly how this OLE container implements data-bound properties.

    WebKitX HMI_VALUE_xxx properties are all data-bound with bindable, displaybind, immediatebind, nonbrowsable IDL attributes. Rockwell FactoryTalk understands WebKitX HMI_VALUE properties as bi-directional and shows them with a dual arrow.

    With WebKitX you can create modern HMI Control Boards by forwarding HTML button clicks and values to the underlying Automation and IoT controllers. The output signals are transmitted in real-time from HTML to the controllers over the HMI_VALUE properties.

    The idea is that you set in JavaScript the HMI_VALUE[index] property to a control signal value (eg. a "pump open command") and it becomes available instantly to the data bound WebKitX.HMI_VALUE property. Every time any of the 255 HMI_VALUE properties change, WebKitX calls BoundPropertyChanged(dispidHMI_VALUE) where OLE containers are expected to get notified, handle the bound property change, and forward the received HMI value to the underlying Automation and IoT controller. Also, for HMI OLE containers that implement COM Connection Points, WebKitX also fires the OnHMIControlSignal event every time a HMI_VALUE property changes its value.

    Option Explicit
    Private Sub Form_Resize()
        On Error Resume Next
        WebKitX1.Move 0, 0, ScaleWidth, ScaleHeight
    End Sub
    Private Sub Form_Load()
        ' Load Human Machine Interface markup
        WebKitX1.HMI_URL = "file:///" + App.Path + "/index.html"
    End Sub
    Private Sub WebKitX1_OnCreate(ByVal Settings As WebKitXCEF3Lib.ISettings, CommandLineSwitches As String)
        ' Set WebKitX HMI values to flush/refresh at rate 1Hz (every 1sec).
        Settings.hmi_input_clock_frequency_hz = 1
    End Sub
    Private Sub WebKitX1_OnPageComplete(ByVal url As String)
        ' We use a timer at 60Hz to simulate high-frequency sensors.
        Timer1.Interval = (1000 / 60)
        Timer1.Enabled = True
    End Sub
    Private Sub Timer1_Timer()
        ' We read values from "sensors" and pass them to six (6) different HMI I/O channels.
        ' We read sensor values 60 times per second (every ~16ms). WebKitX uses input latches
        ' to retain input values and flush them to HTML at a rate of 1Hz (every 1sec).
        WebKitX1.HMI_VALUE_001 = Rnd * 1560
        WebKitX1.HMI_VALUE_002 = Rnd * 1560
        WebKitX1.HMI_VALUE_003 = Rnd * 1560
        WebKitX1.HMI_VALUE_004 = Rnd * 1560
        WebKitX1.HMI_VALUE_005 = Rnd * 1560
        WebKitX1.HMI_VALUE_006 = Rnd * 1560
    End Sub
    Private Sub WebKitX1_OnHMIControlSignal(ByVal Index As Long, ByVal Data As String)
        Debug.Print Format(Time, "HH:MM:SS") & " > HMI_VALUE_" & Format(Index, "000") & " = " & Data
    End Sub
    <!DOCTYPE html>
    <html lang="en" >
    	<meta charset="UTF-8">
    	<title>Gauge Chart</title>
    	<link rel="stylesheet" href="">
    	<link rel='stylesheet' href=',700'>
    	<link rel="stylesheet" href="./style.css">
    This example demonstrates how to use WebKitX HMI features for passing Machine Data directly to HTML5 HMI Elements.
    WebKitX offers 255 bi-directional HMI data channels that you can bind with machines and sensors to create Control Boards or Dash Boards.
    See Documentation on how to use WebKitX HMI properties with Rockwell Automation Studio.
    <main class="main">  
      <div class="gauge-container">
        <div id="gauge1" class="gauge"></div>
        <div id="gauge2" class="gauge"></div>
        <div id="gauge3" class="gauge"></div>
      <div class="gauge-container">
        <div id="gauge4" class="gauge"></div>
        <div id="gauge5" class="gauge"></div>
        <div id="gauge6" class="gauge"></div>
    <svg width="0" height="0" version="1.1" class="gradient-mask" xmlns="">
          <linearGradient id="gradientGauge">
            <stop class="color-red" offset="0%"/>
            <stop class="color-yellow" offset="17%"/>
            <stop class="color-green" offset="40%"/>
            <stop class="color-yellow" offset="87%"/>
            <stop class="color-red" offset="100%"/>
    <script src=''></script>
    <script src=''></script>
    <script  src="./script.js"></script>
    $(function () {
      class GaugeChart {
        constructor(element, params) {
          this._element = element;
          this._initialValue = params.initialValue;
          this._higherValue = params.higherValue;
          this._title = params.title;
          this._subtitle = params.subtitle;
        _buildConfig() {
          let element = this._element;
          return {
            value: this._initialValue,
            valueIndicator: {
              color: '#fff' },
            geometry: {
              startAngle: 180,
              endAngle: 360 },
            scale: {
              startValue: 0,
              endValue: this._higherValue,
              customTicks: [0, 250, 500, 780, 1050, 1300, 1560],
              tick: {
                length: 8 },
              label: {
                font: {
                  color: '#87959f',
                  size: 9,
                  family: '"Open Sans", sans-serif' } } },
            title: {
              verticalAlignment: 'bottom',
              text: this._title,
              font: {
                family: '"Open Sans", sans-serif',
                color: '#fff',
                size: 10 },
              subtitle: {
                text: this._subtitle,
                font: {
                  family: '"Open Sans", sans-serif',
                  color: '#fff',
                  weight: 700,
                  size: 28 } } },
            onInitialized: function () {
              let currentGauge = $(element);
              let circle = currentGauge.find('.dxg-spindle-hole').clone();
              let border = currentGauge.find('.dxg-spindle-border').clone();
              currentGauge.find('.dxg-title text').first().attr('y', 48);
              currentGauge.find('.dxg-title text').last().attr('y', 28);
              currentGauge.find('.dxg-value-indicator').append(border, circle);
            } };
        init() {
      $(document).ready(function () {
        $('.gauge').each(function (index, item) {
          let params = {
            initialValue: 780,
            higherValue: 1560,
            title: 'Temperature',
            subtitle: '780 &deg;C' };
          let gauge = new GaugeChart(item, params);
    function OnHMIDataSignal(index, randomNum)
    	randomNum = parseInt(randomNum);
    	let item = $('.gauge')[index-1];  	
    	let gauge = $(item).dxCircularGauge('instance');
    	let gaugeElement = $(gauge._$element[0]);
    	gaugeElement.find('.dxg-title text').last().html(randomNum+' &deg;C');
    See Also