Open DCS Framework: Integration of 4diac FORTE and Rapid SCADA

Open DCS Framework: Integration of 4diac FORTE as distributed control logic with Rapid SCADA for supervision, visualization, and historization. An open, modular, and vendor lock-in–free alternative for the future of industrial automation.

Written by Ketut Kumajaya — October 2025

Introduction

In the process industry, traditional control systems often rely on closed DCS that are expensive and lack flexibility. The Open DCS Framework emerges as an open, modular, and distributed alternative, leveraging 4diac FORTE as the logic execution layer and Rapid SCADA as the supervisory and visualization layer.

Background

Conventional DCS systems are indeed reliable, but they have limitations:

Dependence on specific vendors (vendor lock-in).
Some vendors impose additional license fees for logic modifications or development.
Difficult to integrate with modern platforms such as IIoT and data analytics.

IEC 61499 introduces a new paradigm: function block–based, event-driven, and distributed control. 4diac FORTE is an open implementation of this standard, enabling a lightweight, portable runtime capable of communicating through protocols such as OPC UA, OPC DA, MQTT, Modbus TCP/RTU.

On the other hand, Rapid SCADA provides supervisory capabilities, visualization, data historization, alarm/event management, and scripting, but lacks deterministic control execution. Integrating the two enables the creation of a complete open DCS.

Open DCS Framework Concept

Architecture

Open DCS Layer	Function	Component
Supervision / HMI	Process visualization, historization, alarms/events	Rapid SCADA
Control Execution	Distributed control logic	4diac FORTE
Communication	Data exchange between nodes, system integration	OPC UA / OPC DA / Modbus TCP/RTU / MQTT
Input/Output Layer	Sensors, actuators, RTUs, PLCs	Moxa ioLogik E2200 / Advantech ADAM-5000 series

Within this Open DCS framework:

Rapid SCADA serves as the operator interface and supervisory hub, including visualization, alarms, and historization.
4diac FORTE executes distributed control logic on control nodes.
OPC UA / OPC DA / Modbus TCP/RTU / MQTT bridge real-time communication between supervision, control, and field devices.
Input/Output Layer consists of sensors, actuators, and industrial I/O devices such as Moxa ioLogik E2200 or Advantech ADAM-5000 series. These I/O devices support Modbus TCP/RTU protocols and digital/analog signal interfaces.

Interaction Mechanism

4diac FORTE control nodes execute function blocks according to the process.
Rapid SCADA, as an OPC UA / OPC DA client, reads and writes data, sending operator commands.
Process changes by FORTE are published to Rapid SCADA for visualization and historization.
Operators monitor performance, alarms, and trends via Rapid SCADA, while FORTE handles deterministic control logic.

Implementation

As an initial step, a simple architecture example:

Control Node: industrial SBC or Raspberry Pi running 4diac FORTE with PID and sequential logic. Estimated initial cost: IDR 2–5 million for a basic setup, including Raspberry Pi 5.
Supervision Node: Linux/Windows server running Rapid SCADA with dashboards displaying pressure, flow, and valve positions.
Field I/O: Modbus TCP/RTU devices such as Moxa ioLogik E2200 series or Advantech ADAM-5000 series for interfacing 4–20 mA sensors and digital actuators. PLCs can be used for critical control execution in compliance with SIL standards.
Connection: communication between FORTE and Rapid SCADA using real-time OPC UA server-client, with native support in Rapid SCADA v6.x for efficient data subscriptions.

Architecture Diagram

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Modbus TCP/RTU
MQTT]:::comm end subgraph Control ["Control Execution"] FORTE[4diac FORTE]:::forte end subgraph Field ["Input/Output Layer"] IO["ioLogik E2200
ADAM-5000
PLCs for SIL"]:::io end SCADA -.->|Command| OPCUA OPCUA -.->|Command| FORTE FORTE -.->|Actuation| IO IO -->|Sensor Feedback| FORTE FORTE -->|Process Status| OPCUA OPCUA -->|Data Historization| SCADA classDef forte fill:#f9f,stroke:#333,stroke-width:2px,color:#000; classDef scada fill:#9cf,stroke:#333,stroke-width:2px,color:#000; classDef comm fill:#fc9,stroke:#333,stroke-width:2px,color:#000; classDef io fill:#cfc,stroke:#333,stroke-width:2px,color:#000; linkStyle 0 stroke:#e33,stroke-width:2px,stroke-dasharray: 5 5 linkStyle 1 stroke:#e33,stroke-width:2px,stroke-dasharray: 5 5 linkStyle 2 stroke:#e33,stroke-width:2px,stroke-dasharray: 5 5 linkStyle 3 stroke:#3a3,stroke-width:2px linkStyle 4 stroke:#3a3,stroke-width:2px linkStyle 5 stroke:#3a3,stroke-width:2px

Integration of Rapid SCADA, 4diac FORTE, and Field I/O Devices, with PLCs for SIL application

Benefits and Challenges

Benefits

Free from licensing and vendor lock-in.
High flexibility and modularity.
Transparent control logic.
Interoperability with IIoT systems and modern data analytics.

Challenges

Large-scale implementation standardization is still evolving.
Cybersecurity requires serious attention.
A new mindset is needed: from fixed cycles (cyclic) to event-driven.
Documentation, deployment, and maintenance become the user’s responsibility.
Community contributions are crucial—for example, several improvements to ensure portability to edge devices such as Raspberry Pi or Siemens IoT.

Notes on Critical Control

The Open DCS Framework based on 4diac FORTE and Rapid SCADA is ideal for regular process control, monitoring, and alarm/event handling.

However, for critical applications, such as safety interlocks, emergency shutdowns, or control with very tight cycle times, industrial PLCs are still recommended as the primary deterministic execution layer.

In this scenario:

FORTE acts as a supervisory or secondary controller.
PLC handles critical logic requiring high determinism.
System integration can be achieved via OPC UA or Modbus, ensuring real-time communication.

SIL (Safety Integrity Level) indicates the reliability level of a system in preventing hazards; critical applications such as emergency shutdowns typically require PLCs that comply with a specific SIL.

Reflection and Development Direction

The Open DCS Framework is not merely a technological combination but a paradigm shift.

Next steps:

Develop Rapid SCADA – 4diac FORTE project templates for common control (flow, level, pressure, temperature).
Build reusable, community-driven function block libraries. Leverage recent contributions in Modbus/OPC UA for robustness.
Establish deployment, monitoring, and auto-scaling mechanisms.
Enhance cybersecurity and integrate real-time technologies such as TSN.

Conclusion

This framework demonstrates that the future of industrial control can be open, distributed, and collaborative. With FORTE as the executor and Rapid SCADA as the supervisory layer, a DCS system that is transparent, flexible, and sustainable can be realized.

“Perhaps the future of industrial automation does not belong to a single vendor — but to those who dare to open it.”