Modular automation in water engineering

Modular automation in just four steps

There’s little you can do about the wide fluctuations in the consumption and quality of raw water. But what you can do is ensure that your water treatment system is able to manage this intelligently. This is where networked Industry 4.0 comes into play, as well as modular automation from Festo.

Modular automation with CPX

Festo has made automation technology smart. Thanks to digitalisation, we can now easily, securely and reliably connect automated modules to each other at the field level and have them work together. The key words here are 'intelligent components' that can be flexibly combined, based precisely on needs and requirements. Each module contains all the automation elements it needs to carry out its own process.

Our automation platform CPX is the centre of all activity for decentralised signal processing and functional control. This gives you much better and more economical control over fluctuating water consumption and raw water quality than with a central control system. If anything is missing, whether it’s a filter system or further process steps, it can simply be connected and activated (i.e. numbering up rather than elaborate scaling up).

Intelligence at field level

Comparison: modular versus centralised

Water engineering: modular automation

Until now, the design and engineering of process-based systems has generally been done as follows: you define a production volume that has to be produced within a particular time, and you then create a process to achieve this. Everything is controlled and monitored by a centralised control system. This works well as long as the required production volume remains the same.

But that is usually not what happens. Or there are fluctuations in the quality of the raw water. Intervening in such a centralised automation system is extremely laborious, because it means all the process and automation technology needs to be modified. And it would also require someone who is familiar with precisely that specific design and how it was programmed. In addition, lower throughput can have an impact on product quality and jeopardise the profitability of the system. Last but not least, service and maintenance are tedious and expensive, since you always have to shut down and restart the entire system.

The concept of modular automation now offers a proper alternative for all industries that treat and use water. Each connected system module is a functional unit in its own right, operates independently and contains the complete control system from Festo. This means that you can connect and disconnect it as required, quickly, easily and economically. Changes to the production volume can thus be implemented flexibly. There is no need to reprogram or reconfigure the application software and maintenance costs also drop significantly.

Practical example: beverage production

Beverage production

The composition of raw water varies depending on the location of the factory. And occasionally contamination can occur too. This means that appropriate steps need to be taken to treat the water and to ensure that you have high-quality water for use in production. This requires a suitable combination of filtration systems: gravel filters, ion exchangers, ultrafiltration or reverse osmosis systems, etc.

Modular automation has a clear advantage in this case, because it can be quickly adapted to changing conditions and the required filtration modules are easy to integrate. This is because each of these modules already contains the necessary automation functions that are implemented using the remote I/O system with an integrated PLC from Festo. As a result, they are easy to expand in line with actual needs.

Your route to modular automation

Taking water filtration as an example, these diagrams illustrate how you can turn a conventional, large-scale process-based system with centralised automation into a modularised, decentralised automated solution in just four steps. To do this, we’ll take a typical water treatment system that was designed to meet the requirements that were defined some time ago and is now difficult to modify (i.e. scale up or down). Modular automation transforms it into a flexible system that allows you to quickly and easily adjust the production volume by removing modules (numbering down) or adding modules (numbering up).

For our example, we’ll take a water filtration system design with a central controller and control system that was once commonly used. The valve terminal is connected to it as a remote I/O system via a fieldbus with a built-in pneumatic section. The components for controlling the field devices are installed in the control cabinet.

Step 1: Divide into subprocesses

These types of conventional water treatment systems are easy to modularise. To start with, the overall process is divided into subprocesses. A module is defined for each subprocess, which contains all the mechanical and automation technology components that are needed for autonomous operation.

Step 2: Modularise automation

Automation is modularised in the same way. The control cabinet components and the central controller (the process-based application software) are divided in such a way that each module is equipped with its own controllers, remote I/O components and pneumatic controls.

Step 3: Coordinate the complete system

Once the modules have been connected to form a process-based system, each module makes its specific functionality available in an encapsulated form via a data interface. The operating mode, status, process measurement values, alarms, etc. can thus be read out or written so that the system functions correctly.

In addition, you also need a process management system that coordinates the module functionalities within the complete system and allows you to manage the entire filtration process. This can turn out to be a much leaner approach than with central controllers. As mentioned before, the process-related control functions are already contained in the modules themselves.

Step 4: Flexibly customise modular systems

Using the modules described, you can build systems in any design to meet your precise needs and actual requirements simply by adding modules that are identical in terms of construction and function. By numbering up instead of scaling up, the system is and remains flexible right from the start.

Modular automation is relatively easy. And with Festo, it’s even easier. Our experts will be happy to advise you.

Arguments in favour of modular automation

The modularisation described here is based on the example of a water filtration system that used to be centrally controlled. However, this basic principle can also be applied to other industrial segments. And it isn’t just system operators who benefit from the flexibility that modular process automation from Festo offers. System builders, too, stand to gain from a modular concept.

Benefits for operators and OEMs

  • Numbering up/down: Modular automation makes it significantly easier to modify the complete system. As a result, engineering tasks can be done more quickly and economically.
  • Transparency: The individual modules from Festo are precisely defined units with clear functionality.
  • Flexibility: This also means that the modules are easy to customise. This simplifies and speeds up the integration of additional process steps.
  • Simplicity: The modules contain their own specific application software. This reduces the complexity of the entire IT landscape.
  • Autonomy: Festo modules are programmed using CODESYS in accordance with IEC 61131. This means there are no licensing fees and you are free to select the automation hardware of your choice.
  • Synergy: OEMs can also produce standardised modules in small batches and test them thoroughly before delivery. You thus benefit from economies of scale in production and assembly; you reduce your costs and you can service the market at the right time.

Water engineering is just the beginning

It is anticipated that there will be a fundamental shift in the design and engineering of process-based systems. NAMUR Recommendation NE 148 already formulates the ‘automation requirements relating to modularisation of process plants’ with Industry 4.0 in mind. In other words, system operators and manufacturers throughout the process industry should check whether their systems already lend themselves to the implementation of modular concepts.

White paper: Systems based on the Lego principle

In this clear and comprehensive white paper, we explain the transition to modular automation in process-based systems based on the example of water filtration.

Click here to download the PDF.