Industrial control systems (DCS)

Distributed control systems (DCS), PLCs and their associated equipment are ICSS’s core business. Services cover engineering, installation, commissioning, diagnostics, modifications, maintenance and long-term operational support for existing systems.

A control system is not limited to the logic executed by its controllers. It also includes engineering and operator workstations, historians, networks, gateways, redundancy mechanisms, time synchronisation, interfaces with third-party equipment, and the tools used to generate, load and maintain the project.

Understand and modify the complete system

To diagnose a fault or prepare a change, ICSS can correlate project configuration, events, historical data, network traces, controller logs and observed plant behaviour. This method follows information from its field measurement through its use in logic, display on the HMI and actual effect on the process.

The work may address a targeted issue or span several components: instrumentation, controllers, networks, HMI, communication with third-party equipment, control loops or operating sequences. It also considers interactions between systems and the risks associated with modifications performed on an operating unit.

ALSPA P320 DCS expertise

ICSS’s longstanding expertise focuses on ALSPA P320, from Series 4 with C370 controllers through Series 5/5.1 and 6/6.1. It covers Controcad, Centralog, controllers, the databases used — particularly Oracle, RDM Server and Informix — generation and loading chains, networks, gateways and tools specific to the different system generations.

This knowledge enables ICSS to work throughout the life cycle of an ALSPA P320 project. Services may include:

• Complete installation and commissioning of the control system.
• Adding a controller, operator station, program, Controcad engineering workstation or other equipment to an existing architecture.
• Virtualising obsolete workstations while retaining the applications, interfaces and legacy functions required for operation.
• Migrating projects between different ALSPA P320 versions or generations, and preparing and supporting retrofits.
• Commissioning functions such as DEPP 2000, Historian, redundancy, alarm filtering or automatic report generation with IMS and CRW.
• Integrating third-party systems through CSS-G and CSS-F gateways, including their configuration and the associated communication protocols.
• Combining several Controcad projects in a single database to centralise their engineering and restore overall system consistency.
• Developing or adapting libraries, Basic Functions and function blocks for specific project requirements.
• Advanced modification of engineering tools, HMI systems, generation mechanisms or internal system exchanges.
• Diagnosing system faults and logic anomalies, including intermittent faults, issues distributed across several devices or problems that are difficult to reproduce.
• Training operations, maintenance and engineering teams, from routine system use to advanced technical topics.
• Independent expertise on obsolescence management, spare-parts strategy, the benefits and risks of a retrofit, or methods for implementing and testing a new control strategy.

Emerson Ovation and mixed architectures

ICSS also has hands-on experience with Emerson Ovation, supplemented in 2025 by a ten-day “Ovation System Maintenance” course delivered by Emerson in Saint-Priest, France.

This expertise was applied at Sohar 3, a 1,710 MW combined-cycle power plant using a mixed ALSPA and Ovation architecture. Work included backups and virtual-machine preparation, controlled online modifications on both systems, changes to logic and operator displays for the HRSGs, and the addition of new data exchanges.

The assignment also included diagnosing Modbus communication between Ovation and the ALSPA Controgas and Controsteam systems, with analysis of redundancy mechanisms, read and write paths, watchdogs and recovery after communication loss. This cross-platform experience is particularly useful when Ovation and ALSPA must coexist, exchange information or be modified without shutting down the plant.

Other industrial control systems and automation

ICSS can also work on other control systems, including Siemens PCS 7, PcVue and multi-vendor architectures. Commissioning experience provides a method for approaching a new system through its documentation, architecture, engineering tools and actual plant behaviour.

Regardless of the platform used, services may include:

• Designing and implementing logic modifications for different industrial processes, with extensive experience of combined-cycle and conventional power plants.
• Creating, modifying and tuning control loops, sequences, protections and operating modes.
• Commissioning new equipment, automation, interfaces or functions.
• Analysing risks associated with the process, control system and interactions between multiple items of equipment.
• Diagnosing instrumentation, wiring, acquisition or measurement-processing faults.

Field-proven work

This expertise has been applied at combined-cycle and conventional power plants, hydroelectric, geothermal and concentrated solar power installations, and other industrial processes. Assignments range from complete system installation to resolving a blocking fault, modifying a control strategy on an operating unit, sustaining an obsolete architecture or developing a solution not available in standard tools.