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Oct 18, 2023

Integrating NOA and Ethernet-APL into process control with PC-based control

Digitalize efficiently with extended automation architecture and new data communication

The process industry needs to keep pace with the digitalization trend, but sprawling process engineering systems have special requirements that need to be met. NAMUR Open Architecture (NOA) and the new Ethernet-APL communication technology can be used to implement appropriate solutions quickly and efficiently. This can be achieved right now, with existing control technology, using the Beckhoff NOA edge device and the ELX6233 EtherCAT Terminal.

Concepts such as Industry 4.0 and the Internet of Things are based on collecting all a plant’s operating data and making it available to various applications. This data is evaluated in analytical tools, e.g., in order to detect failures in field devices at an early stage. It can also be used to optimize processes and increase productivity. However, implementing IoT concepts is particularly challenging in established plants, as the information required from the field devices is not captured in the existing automation architecture.

With the NAMUR Open Architecture (NOA), the process industry can be digitalized without changing the established control technology.
With the NAMUR Open Architecture (NOA), the process industry can be digitalized without changing the established control technology.

NAMUR has therefore developed NAMUR Open Architecture (NOA). This concept extends the automation architecture without altering the existing control system. NOA's core task is therefore to provide information from the field level to higher-level applications in order to monitor and optimize the plant (M+O). The challenge lies in the fact that the interfaces of the field devices differ, based on their manufacturer and type. The focus here is on parameters which are read out cyclically, which contain information on device status or process quality.

Edge device for NOA

Beckhoff has developed an NOA edge device specifically for reading out the additional operating data for the higher-level M+O. This consists of a compact embedded PC, EtherCAT Terminals with HART functionality, and the relevant TwinCAT project, and can be placed directly in the plant or in the control room. Field devices are connected to the edge device via a second channel, implemented by a signal isolator. Using the HART protocol, the required commands can be sent to the field device and the additional data can be read out. The data is converted, translated, and structured within the edge device. Then an information model stored on the OPC UA server is filled out. This model is typically based on the PA-DIM, but can also be customized.

The NOA concept has a lot of potential, particularly for brownfield applications. Existing plants need to be future-proofed by converting or upgrading them: costs can be reduced and output increased by simply monitoring and optimizing plants without changing the current process control methods. If, in addition to data from established field devices, diagnostic data is also acquired by additional sensors, for example for vibration or temperature measurement, EP series IP67-protected I/O box modules installed directly in the field can prove incredibly useful. Several sensors are connected to one module and the signals are transmitted to the edge device collectively via one cable. This version cuts down on cable routing work while also reducing the space required in the control cabinet.

With the ELX6233 2-channel communication interface, Ethernet-APL field devices can be integrated into the control architecture on a compact, modular basis.
With the ELX6233 2-channel communication interface, Ethernet-APL field devices can be integrated into the control architecture on a compact, modular basis.

The NOA concept also offers advantages for greenfield plants: additional monitoring sensors can be installed in the plant planning stage, thus providing more data for monitoring and optimization. New forms of technology such as Ethernet-APL make this easier to implement. The Ethernet-APL concept aims to implement the entire communication in process technology plants – from the field level to higher-level control systems – on an Ethernet basis. This not only focuses on the pure process data, but more specifically on the status information of the field device. The increased transmission rate compared to fieldbus systems also allows web servers to be used for parameterization or downloading data sheets or certificates directly from the field device.

However, users face a number of challenges during implementation: APL-capable field devices are required to allow the aforementioned advantages to be implemented immediately across the board. However, as this technology is still in its early days, the market does not yet offer a broad portfolio. In established plants, there is also a lack of space for installing additional infrastructure components such as switches. Implementing Ethernet-based communication technology down to field level also requires new functions and policies for IT and OT security.

Seamless integration of Ethernet-APL via EtherCAT Terminal

How can users integrate Ethernet-APL into their plants and benefit from the many advantages it offers right now? One solution is to combine the new technology with proven standards such as the HART protocol. Existing plants can thus be successively digitalized with new APL devices and the barriers to a complete changeover can be dismantled. For these reasons and more, Beckhoff has already integrated Ethernet-APL technology into the modular terminal portfolio: the ELX6233 EtherCAT Terminal offers a 2-channel communication interface for Ethernet-APL. Contrary to the typical field switch concept, this creates an alternative for integrating APL field devices. The modular system allows the user to install the exact required number of Ethernet-APL channels in the control cabinet, saving valuable space and allowing the application to be expanded flexibly.

The scalability of the ELX6233 provides efficient solutions for integrating Ethernet-APL field devices in small test setups as well as for large process plants. As part of the EtherCAT Terminal system, the ELX6233 can be combined with other digital and analog I/Os so that standard electrical signals or communication protocols can be integrated in addition to Ethernet-APL. When it comes to digitalization, direct connection to CX Embedded PCs in particular offers a whole host of advantages, including enabling gateway applications to process data from the field and filter it before sharing it further.

Like many of the EtherCAT Terminals from the Beckhoff portfolio, the ELX6233 can be mounted in zone 2 hazardous areas and allows Ethernet-APL field devices to be connected from zone 0. The interfaces comply with the specifications of IEC 60079-47 and follow the SPAA port profile.

Ethernet-APL, as mentioned, also leads to further challenges in terms of IT and OT security. Unlike many PROFINET architectures, the controller is located directly in the EtherCAT Terminal and not in the higher-level controller. Data security is also significantly higher than it is with classic switched networks due to the separation of individual ports and protocols. In addition, performance can be significantly increased in terms of cycle times, as EtherCAT enables the process image to be made more compact in terms of data size in comparison to other fieldbuses.

Ethernet-APL opens up many possibilities for the user. If this technology is to be implemented quickly, it is vital that it can be integrated into established installations. The ELX6233 EtherCAT Terminal offers the user the flexibility, modularity, expandability, and security required for this.