Modernizing SCADA Control Interfaces: A Visual Path to Web-Based Industrial Dashboards

The most dangerous component in a modern power plant or manufacturing floor isn't a high-voltage transformer or a high-pressure valve—it’s a legacy ActiveX control running on an unpatched Windows XP terminal. For decades, Supervisory Control and Data Acquisition (SCADA) systems have been the backbone of critical infrastructure, yet their interfaces remain trapped in a graveyard of proprietary runtimes and brittle, undocumented code. When the original vendor is long gone and the source code is a "black box," the risk of system failure becomes an existential threat to the enterprise.

The traditional path to modernizing scada control interfaces involves a grueling 18-to-24-month rewrite cycle that often fails before it reaches the production floor. With $3.6 trillion in global technical debt looming over the industrial sector, the "rip and replace" strategy is no longer viable. We need a way to extract the tribal knowledge embedded in these legacy screens without needing the original source files.

TL;DR: Legacy SCADA systems are hindered by 20-year-old UIs and a 67% lack of documentation. Traditional manual rewrites take 40 hours per screen and have a 70% failure rate. Replay introduces Visual Reverse Engineering, converting video recordings of legacy workflows into documented React components and Design Systems. This reduces modernization timelines from years to weeks, achieving up to 70% time savings and providing a secure, web-based path for industrial dashboards.

The Technical Debt of Industrial UIs#

Industrial environments are uniquely plagued by "frozen" technology. While the consumer web moved from jQuery to React and beyond, SCADA interfaces remained static to avoid disrupting critical operations. According to Replay's analysis, the average enterprise SCADA system is currently carrying over 15 years of technical debt, often relying on technologies that modern browsers won't even execute.

The problem isn't just aesthetic. Legacy interfaces lack the responsiveness required for mobile monitoring, the security features needed for SOC2 compliance, and the extensibility to integrate with modern AI-driven predictive maintenance. When you attempt modernizing scada control interfaces through manual methods, you encounter the "Documentation Vacuum." Industry experts recommend a thorough audit before any migration, yet 67% of these systems have no surviving documentation. Engineers are forced to guess the logic behind every button and gauge.

Visual Reverse Engineering is the automated process of converting UI recordings into functional code and design documentation, bypassing the need for original source code or outdated documentation.

By using Replay, teams can record a technician performing standard operating procedures (SOPs) on the legacy system. The platform’s AI Automation Suite then deconstructs those visual frames into a structured Design System.

Why Manual Rewrites Fail the Factory Floor#

The statistics are sobering: 70% of legacy rewrites fail or significantly exceed their projected timelines. In a SCADA context, a failed rewrite isn't just a budget overage; it’s a safety risk.

Manual migration requires a developer to sit with an operator, watch them click, and then attempt to recreate that pixel-perfect behavior in a modern framework like React or Vue. This process takes roughly 40 hours per screen when you factor in CSS styling, state management, and unit testing. With Replay, that same screen is processed in 4 hours. You aren't just copying the look; you are capturing the intent of the interface.

Modernizing SCADA Control Interfaces with React and TypeScript#

The goal of modernizing scada control interfaces is to move away from monolithic, proprietary binaries toward a component-based architecture. React is the industry standard for this transition because of its robust ecosystem and ability to handle high-frequency data updates via WebSockets or MQTT.

When Replay processes a legacy SCADA recording, it identifies repeatable patterns—valves, pumps, gauges, and alarm panels—and populates your Library. These aren't just static images; they are functional React components.

Implementation: Building a Resilient Valve Component#

Below is an example of a modern, TypeScript-based SCADA component that might be generated after a Replay session captures a legacy hydraulic control.

typescript
import React from 'react';

interface ValveProps {
  id: string;
  status: 'OPEN' | 'CLOSED' | 'TRANSITION' | 'FAULT';
  pressure: number;
  onToggle: (id: string) => void;
}

const IndustrialValve: React.FC<ValveProps> = ({ id, status, pressure, onToggle }) => {
  const getStatusColor = () => {
    switch (status) {
      case 'OPEN': return '#22c55e'; // Green
      case 'CLOSED': return '#ef4444'; // Red
      case 'TRANSITION': return '#f59e0b'; // Amber
      case 'FAULT': return '#7c3aed'; // Purple (Standard for fault)
      default: return '#94a3b8';
    }
  };

  return (
    <div className="p-4 border rounded-lg bg-slate-900 text-white shadow-lg">
      <div className="flex justify-between items-center mb-4">
        <h3 className="text-sm font-mono">VALVE_ID: {id}</h3>
        <div 
          className="w-4 h-4 rounded-full animate-pulse" 
          style={{ backgroundColor: getStatusColor() }}
        />
      </div>
      <div className="text-2xl font-bold mb-2">
        {pressure.toFixed(2)} <span className="text-xs text-slate-400">PSI</span>
      </div>
      <button
        onClick={() => onToggle(id)}
        className="w-full py-2 bg-blue-600 hover:bg-blue-700 rounded transition-colors font-semibold"
      >
        Toggle State
      </button>
    </div>
  );
};

export default IndustrialValve;

This component represents the "Atomic" level of your new design system. By using Replay’s Flows feature, you can then map how these components interact across a complex multi-screen dashboard.

Handling Real-Time Telemetry in the Web Browser#

The biggest challenge in modernizing scada control interfaces is the data layer. Legacy systems often use "polling" or proprietary DDE/OPC links. Modern web dashboards require a more efficient approach to handle the thousands of tags generated by a PLC (Programmable Logic Controller).

Industry experts recommend using a custom React hook to manage the lifecycle of a telemetry stream. This ensures that the UI remains responsive even when receiving 60 updates per second.

typescript
import { useState, useEffect } from 'react';

export function useScadaTelemetry(tagId: string) {
  const [data, setData] = useState<number | null>(null);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    // In a real scenario, this would connect to an MQTT broker or WebSocket
    const socket = new WebSocket(`wss://factory-gate.enterprise.com/tags/${tagId}`);

    socket.onmessage = (event) => {
      const payload = JSON.parse(event.data);
      setData(payload.value);
    };

    socket.onerror = () => {
      setError("Connection to PLC Gateway lost.");
    };

    return () => socket.close();
  }, [tagId]);

  return { data, error };
}

By combining Replay’s visual output with a robust data-fetching strategy, you transform a brittle legacy terminal into a high-performance web application. This is the core of Legacy Modernization Strategies that actually work in high-stakes environments.

The Replay Workflow: From Recording to Production#

How does Replay actually accelerate the process of modernizing scada control interfaces? It follows a four-step "Visual-to-Code" pipeline:

1. •Capture: An operator records their screen while performing routine tasks on the legacy SCADA software. No access to the source code or backend is required at this stage.
2. •Deconstruct: Replay’s AI analyzes the video, identifying UI elements, layout hierarchies, and state changes (e.g., a pump turning red when stopped).
3. •Generate: The platform generates a Blueprint — an editable, high-fidelity representation of the UI that exports directly to clean TypeScript/React code.
4. •Integrate: Developers take the generated components and hook them up to modern APIs, authentication layers, and data streams.

According to Replay's analysis, this workflow eliminates the "blank page" problem. Instead of spending weeks trying to figure out the exact hex code of a 1998-era warning light or the padding of a data table, developers start with a fully documented component library that mirrors the legacy system's functionality perfectly.

Security and Compliance in Regulated Industries#

When modernizing scada control interfaces, security cannot be an afterthought. Many industrial systems operate in air-gapped environments or must adhere to strict SOC2, HIPAA, or government regulations.

Replay is built for these environments. Unlike generic AI coding tools that require sending sensitive data to the cloud, Replay offers:

• •On-Premise Deployment: Run the entire Visual Reverse Engineering pipeline within your own secure network.
• •SOC2 & HIPAA Readiness: Ensure that the modernization process itself meets the highest standards of data governance.
• •Audit Trails: Every component generated by Replay can be traced back to the original video frame, providing a clear audit trail for compliance officers.

For more on how to maintain security during a transition, see our guide on Modernizing Regulated Systems.

The Future of Industrial Dashboards#

As we look toward Industry 4.0, the goal is no longer just to "see" what is happening on the factory floor, but to interact with that data in real-time from anywhere in the world. Modernizing scada control interfaces is the first step toward building a "Digital Twin" of your operations.

By moving away from 40-hour-per-screen manual rewrites and embracing Replay’s 4-hour visual approach, enterprises can finally clear their technical debt. The 18-month average enterprise rewrite timeline is a relic of the past. In the modern era, we record, we replay, and we deploy.

Comparison Table: Modern vs. Legacy SCADA Architectures#

Frequently Asked Questions#

Why is modernizing scada control interfaces so difficult?#

The difficulty lies in the lack of documentation and the use of proprietary, "closed" technologies like ActiveX or Silverlight. Most legacy SCADA systems have been patched so many times that no single person understands the entire codebase. This creates a high risk of regression during a manual rewrite.

Can I modernize my SCADA UI without the original source code?#

Yes. Using Replay’s Visual Reverse Engineering, you only need a video recording of the interface in action. The platform analyzes the visual output to recreate the components and layout in React, allowing you to build a modern frontend that communicates with your existing PLC backend via a gateway.

How does Replay handle complex industrial animations?#

Replay’s AI Automation Suite is designed to recognize state-based changes in UI elements. If a tank fills up in the video recording, Replay identifies that as a dynamic property and generates the corresponding logic in the React component, allowing you to bind it to a real-time data tag easily.

Is the code generated by Replay "clean"?#

Yes. Replay focuses on generating human-readable, maintainable TypeScript and React code. It follows modern best practices, including component modularity and CSS-in-JS or Tailwind styling, ensuring that your team can maintain the system long after the initial modernization is complete.

Does Replay work for air-gapped systems?#

Absolutely. Replay offers an on-premise version of its platform specifically for industrial and government clients who cannot move their data or recordings to the public cloud. This ensures you can modernize your interfaces while maintaining total control over your intellectual property.

Ready to modernize without rewriting? Book a pilot with Replay