WinCC Unified Open Pipe - PLC HMI SCADAS

WinCC Unified Open Pipe is an interface that allows connecting custom applications to the WinCC Unified Runtime. Open Pipe provides a limited set of functionalities. However, its main advantage lies in flexibility, as the connection code can be written in any programming language that supports the "pipes" technology, such as Python, Node.js or PowerShell.

After the description, you cannot miss the documentation you need :-)

Enhancing your SCADA WinCC Unified Runtime

The goal of the project is for our Node.js project to subscribe to the alarms of the WinCC Unified Runtime and, when it detects a high priority alarm, to play the alarm text through the speakers of the SCADA Server in the control room.

General flow of the project:

Create a project in Node.js that communicates with the WinCC Unified Runtime and allows us to subscribe to alarms to receive notifications.
The steps to create the project once Node.js is installed

The app.js code that you can copy directly

Code

const net = require('net');
const express = require('express');
const say = require('say');

const app = express();
const PORT = 3000;
const pipePath = '\\\\.\\pipe\\HmiRuntime';

let lastAlarmValue = "FALSE"; // Previous alarm state
let clients = []; // List of connected clients

// Connection with Open Pipe
const client = new net.Socket();

client.connect(pipePath, () => {
  console.log('Connected to Open Pipe');

  // Command to subscribe to alarms
  const subscribeCommand = JSON.stringify({
    Message: "SubscribeAlarm",
    Params: {
      SystemNames: [],
      Filter: "Name = 'AlarmOpenPipe'",
      LanguageId: 1033
    },
    ClientCookie: "myAlarmSubscription"
  }) + '
';

  client.write(subscribeCommand);
  console.log('Subscription sent to the server.');
});

// Listen for data from Open Pipe
client.on('data', (data) => {
  const response = data.toString();

  try {
    const jsonResponse = JSON.parse(response);

    if (jsonResponse.Message === "NotifySubscribeAlarm") {
      const alarms = jsonResponse.Params?.Alarms;

      if (!alarms || alarms.length === 0) return;

      alarms.forEach(alarm => {
        const message = alarm.EventText?.trim();
        const alarmValue = alarm.Value;

        if (!message) return;

        // Detect only the change from 0 to 1 (alarm activated)
        if (lastAlarmValue === "FALSE" && alarmValue === "TRUE") {
          console.log(`ALARM ACTIVATED: ${message}`);

          // Send to subscribed clients and clear the list
          clients.forEach(res => res.json({ alarm: alarm.Name, text: message }));
          clients = [];

          // Use voice to play the message
          say.getInstalledVoices((voiceErr, voices) => {
            if (!voiceErr) {
              const chosenVoice = voices.find(v => v.toLowerCase().includes('helena'))
                || voices.find(v => v.toLowerCase().includes('sabina'))
                || 'Microsoft Helena Desktop';
              say.speak(message, chosenVoice);
            } else {
              console.error('Error getting voices:', voiceErr);
            }
          });
        }

        lastAlarmValue = alarmValue; // Update alarm state
      });
    }
  } catch (error) {
    console.error('Error processing the response:', error);
  }
});

// Connection error handling
client.on('error', (error) => {
  console.error('Connection error:', error);
});

// API for subscriptions
app.get('/subscribe', (req, res) => {
  clients.push(res);
});

// Start server
app.listen(PORT, () => {
  console.log(`API server running at http://localhost:${PORT}`);
});

And we have everything necessary set up...

And a picture is worth a thousand words… a few seconds of video!
Turn on the sound ;-)

Jose Manuel Luque

Industrial Automation Technician.