node-red-contrib-minelert-universal-io/level-to-ma.html

Node-RED nodes for Universal IO Gateway and I/O Modules

<script type="text/javascript">
    RED.nodes.registerType('level-to-ma', {
      category: 'Smartlink UIO',
      color: '#c0deed',
      defaults: {
        name: {value: ""},
        mode: {value: "distance", required: true},
        unit: {value: "m"},
        min: {value: 0},
        max: {value: 5},
        tankHeight: {value: 5}
      },
      inputs: 1,
      outputs: 1,
      icon: "function.png",
      paletteLabel: "Level to mA",
      label: function () {
          return this.name || 'Level to mA';
      },
      oneditprepare: function() {
        $("#node-input-mode").change(function() {
          const mode = $(this).val();
          if (mode === "distance") {
            $(".distance-options").show();
            $(".level-options").hide();
          } else {
            $(".distance-options").hide();
            $(".level-options").show();
          }
        }).trigger("change");
      }
    });
  </script>

  <script type="text/x-red" data-template-name="level-to-ma">
    <div class="form-row">
      <label for="node-input-name"><i class="fa fa-tag"></i> Name</label>
      <input type="text" id="node-input-name" placeholder="Name">
    </div>
    
    <div class="form-row">
      <label for="node-input-mode"><i class="fa fa-cogs"></i> Mode</label>
      <select id="node-input-mode">
        <option value="distance">Distance</option>
        <option value="level">Level</option>
      </select>
    </div>

    <div class="form-row">
      <label for="node-input-unit"><i class="fa fa-ruler"></i> Input Unit</label>
      <select id="node-input-unit">
        <option value="m">meters</option>
        <option value="cm">centimeters</option>
        <option value="mm">millimeters</option>
      </select>
    </div>
    
    <div class="form-row distance-options">
      <label for="node-input-min">Min distance (m)</label>
      <input type="number" id="node-input-min">
    </div>
    
    <div class="form-row distance-options">
      <label for="node-input-max">Max distance (m)</label>
      <input type="number" id="node-input-max">
    </div>
    
    <div class="form-row level-options">
      <label for="node-input-tankHeight">Tank Height (m)</label>
      <input type="text" id="node-input-tankHeight" >
    </div>
  </script>
  
  <script type="text/x-red" data-help-name="level-to-ma">
    <p>
      This node converts a measured <strong>distance</strong> or <strong>level</strong> input into a corresponding <strong>4–20 mA analog signal</strong> equivalent.
    </p>
  
    <p>
      The node supports two operating modes:
      </p>
      <ul>
        <li><strong>Distance Mode:</strong> Converts a distance reading to mA output based on user-defined <strong>minimum</strong> and <strong>maximum</strong> thresholds.</li>
        <li><strong>Level Mode:</strong> Calculates level as the difference between <strong>tank/container height</strong> and the measured distance. Outputs corresponding mA value.</li>
      </ul>
    
    <p>
      You can also select the unit of the incoming measured input (e.g., mm, cm, m).
    </p>
  
    <p>
      <strong>Output Format:</strong><br/>
      The node outputs an object with the following structure:
    </p>
  
    <code>
    {
      "readingToMeter": 1.989,
      "value": 8.011,
      "percent": 80.11,
      "mA": 16.82
    }
    </code>
  
    <ul>
      <li><strong>readingToMeter:</strong> Measured input converted to meters</li>
      <li><strong>value:</strong> Calculated level or distance (depending on mode), in meters</li>
      <li><strong>percent:</strong> Scaled percentage from 0 to 100%</li>
      <li><strong>mA:</strong> Final calculated analog output in mA (scaled between 4–20)</li>
    </ul>
  
    <p>
      The node also supports variable input using environment-style placeholders such as <code>${TankHeight}</code> for dynamic configuration.
    </p>
  </script>