Many power and industrial plants around the world are operating with legacy DCS equipment that is becoming obsolete, difficult to maintain, and a cybersecurity risk. Modernization is not a question of "if" but "when." The ABB NDCU-21C controller is a cornerstone of ABB's Symphony Plus platform, which is specifically designed as a migration path for existing Symphony Harmony or even older System 6 (INFI 90) users. This guide explores the role of the NDCU-21C in a control system modernization strategy.
The Drivers for Modernization
Key reasons for upgrading a control system include:
- Obsolete Hardware: Difficulty sourcing spares for old controllers and I/O modules.
- Cybersecurity Risks: Legacy systems lack modern security features.
- High Maintenance Costs: Increasing time and money spent on troubleshooting.
- Need for Better Performance: Desire for improved data analytics, connectivity, and operational efficiency.
The ABB NDCU-21C as a Modernization Platform
The Symphony Plus platform, with the NDCU-21C at the controller level, is designed for backward compatibility and a phased migration approach.
1. The Migration Path: From Legacy to Symphony Plus
A key advantage is that the Symphony Plus system can coexist with an existing Symphony Harmony system on the same network. This allows for a gradual, unit-by-unit migration, which minimizes risk and capital outlay.
- Step 1: An old controller (e.g., an MFC01) controlling a boiler can be replaced with a new NDCU-21C.
- Step 2: The new NDCU-21C connects to the existing plant network and can use existing S800 I/O or new S800 I/O modules.
- Step 3: Operators can monitor both the new boiler (via the NDCU-21C) and the old parts of the plant from the same modern operator stations.
This "like-for-like" replacement strategy is often the first, lowest-risk step in a full plant modernization.
2. Enhanced Capabilities with the NDCU-21C
Upgrading to an NDCU-21C from a legacy controller brings immediate benefits:
- Increased Processing Power: Handles more complex control algorithms and larger data volumes.
- Improved Cybersecurity: Features modern security protocols to protect against network threats.
- Better Connectivity: Easier integration with higher-level systems like Manufacturing Execution Systems (MES) and Enterprise Resource Planning (ERP) via standard protocols like OPC UA.
- Modern Engineering Tools: Programming with Control Builder M is more efficient than older tools, supporting modern software engineering practices.
Planning a Modernization Project with the NDCU-21C
Phase 1: Assessment and Planning
- Inventory Existing System: Document all current controllers, I/O, and network structure.
- Define Migration Scope: Decide on a big-bang replacement or a phased approach. A phased approach is usually preferred.
- Develop a Detailed Plan: Create a step-by-step plan for each unit to be migrated, including downtime windows.
Phase 2: Engineering and Design
- Control Logic Conversion: The existing application code from the old controller must be converted and tested for the new NDCU-21C in Control Builder M.
- Hardware Design: Design the new cabinet layouts for the NDCU-21C and associated I/O.
- Network Integration: Plan the integration of the new controllers into the existing or new plant network.
Phase 3: Implementation and Commissioning
- Staged Installation: Install and commission the new NDCU-21C controllers one unit at a time during planned outages.
- Thorough Testing: Perform factory acceptance testing (FAT) and site acceptance testing (SAT) to ensure the new system operates identically—or better—than the old one.
- Training: Train operations and maintenance staff on the new system features.
Conclusion
Modernizing a control system with the ABB NDCU-21C is a strategic investment that enhances reliability, security, and operational intelligence. Its design within the Symphony Plus framework offers a clear, low-risk migration path from older ABB systems, protecting your existing automation investment while paving the way for a more efficient and connected plant future.
