As manufacturers look for ways to improve centralized machine visibility and support operational decision-making, many face constraints imposed by legacy equipment, validated machine logic, and the need to avoid downtime or added operational risk. A distributed HMI architecture that is aggregated to a more-powerful central HMI, may offer a practical alternative to traditional SCADA approaches. The following use case is authored by Eddy Alan an automation and controls engineer and documents a real-world implementation built entirely on these principles.
The Problem
The company aimed to implement a central monitoring system with the purpose of supporting operational and managerial decision-making, without performing centralized machine control.
The functional scope was clearly defined as monitoring only, including:
- Machine status
- Alarms
- Production data
- Operating time, idle time, and setup/preparation time
- Historical data stored in a database
The environment was characterized by:
- Approximately 500 distributed machines, operating 1 to 3 shifts depending on production demand.
- A brownfield environment with high diversity of manufacturers and protocols (e.g., LS Master-K, LS XBC, among others).
- A significant legacy already in place, including around 100 machines equipped with Weintek MT8072iP HMIs.
- An explicit requirement to avoid rewriting machine logic, prevent production downtime, and not introduce additional operational risk.
Although a classic SCADA system was initially considered, it became clear that even for a purely informational scope, the traditional approach would require significant machine reengineering, extensive use of Modbus, reinterpretation of machine states, and long deployment timelines.
Architecture and Approach
The key insight of the solution was recognizing that the existing legacy already contained the necessary intelligence for monitoring, making it possible to structure the system using a distributed approach.
The adopted architecture was based on the following principles:
- MT series HMIs were used as remote supervision nodes (slaves), fully preserving:
- Local logic
- Machine semantics
- Already validated operational states
- No HMI screens or machine logic were rewritten; the HMIs only needed to be connected to the network.
- Each MT exposes standardized states (status, alarms, production, time metrics) to the central system.
The central system was implemented using the Weintek FHDX-820, which acts as a state aggregator, without any knowledge of:
- PLC manufacturers
- field protocols
- internal machine logic
Onboarding new machines is performed simply by adding an IP address and logical identification, using standardized templates for screens and data.
Cost and Deployment
The system cost was practically zero, since:
- The MT HMIs were already installed.
- The FHDX was already part of the existing infrastructure.
- No SCADA licenses were required.
- No industrial PC or external middleware was needed.
The effort was limited exclusively to:
- Configuration
- Standardization
- Creation of the logical supervision model
Functional Benefits Achieved
- 24/7 monitoring, with continuous scalability.
- SCADA access via cMT Viewer, allowing:
- Up to 10 simultaneous internal connections.
- Up to 3 simultaneous remote connections.
- An additional and unplanned benefit was identified:
- The network topology enabled full remote maintenance on any PLC or HMI in the plant using EasyAccess 2.0, significantly reducing travel and response time.
- Use of Weincloud as a web-based SCADA, allowing machine status visualization by different user profiles, from any location, strictly for monitoring and decision-making purposes.
- Integration with external systems through the Weintek G01, acting as an MQTT ↔ OPC bridge, including integration with a previously mentioned critical energy system, while maintaining domain separation and read-only operation.
Results
- Consolidation of a central decision-support monitoring system, without interfering with machine operation.
- Clear visibility of:
- Operating time
- Idle time
- Setup/preparation time
- Production bottlenecks
- Reliable historical data for analysis and decision support.
- No machine downtime required for deployment.
- No duplication of logic or semantics.
- No recurring costs (subscriptions or annual fees).
- Transformation of existing legacy into a strategic asset, rather than a technical liability.
Conclusion
Overall, the value of the solution was not in adding centralized intelligence or control, but in achieving reliable visibility, secure remote access, and consistent historical data, fully aligned with the goal of supporting decision-making, without turning monitoring into a plant-wide reengineering project.
The key differentiator was recognizing that the Weintek ecosystem already enabled this architecture natively, requiring only proper structuring and interconnection of existing components.
What This Means for Legacy System Modernization
This use case demonstrates how a distributed HMI monitoring architecture can deliver centralized machine visibility and support operational decision-making while fully respecting legacy systems and existing machine logic. The architectural simplicity and ability to reuse already installed HMIs may allow organizations to modernize visibility and analytics capabilities without reengineering the entire system or introducing new technologies that require costly integration or subscriptions.
Key Takeaways:
- Supporting multiple protocols is essential for meeting strict application needs.
- The protocol chosen should always reflect the structure, processing speed, and feature requirements of the application.