What is Ethernet-APL?

Ethernet-APL: New communication standard for the process industry

The newly developed Ethernet-APL communication standard enables fast and seamless communication of all field device data in process industry plants.

As digitalization continues in the process industry, the volumes of data provided by intelligent sensors and actuators are also growing. For a long time, however, there was no communication standard to transmit this data quickly and across multiple levels of the automation structure. Certain properties have to be present for use in process industry plants, such as the ability to connect field devices over long distances and the ensuring of explosion protection.

Thus, to meet these requirements, process industry organizations and companies have developed the Ethernet Advanced Physical Layer (Ethernet-APL). This new communication technology is based on the 10BASE-T1L Ethernet standard, which allows a maximum cable length of 1000 meters and a transmission rate of 10 Mbit/s. Power supply limits in all zones throughout the hazardous area are defined by IEC specification 60079-47 (2-WISE). Power and data are transmitted over the same pair of wires (single pair Ethernet) with Ethernet-APL. To simplify installation and improve the connectivity of the devices used, the project group has also defined port profiles in the TS10186 technical specification: In addition to information on the connection and segment class, a port profile also includes the Ex approval of the respective device connection.

power and data transmission via a single pair of wires
seamless communication of all field device data
long range thanks to flexible topologies
transmission rate up to 300 times faster than existing communication standards in the process industry
flexible application for various protocols such as PROFINET, EtherNet/IP, and OPC UA
proof of intrinsic safety is not required due to defined properties of the connections and cables
rapid integration into existing systems through the use of existing cables
simple implementation of the NAMUR Open Architecture

Implementing Ethernet-APL with Beckhoff

Complete data acquisition with Ethernet-APL: With the ELX6233 EtherCAT Terminal, Ethernet-APL field devices can be integrated in a modular way.

The vision of the Ethernet-APL concept is to implement the entire communication in process technology plants – from the field level to higher-level control systems – on an Ethernet basis. New Ethernet-APL-capable field devices are also required to retrofit entire plants. Since the technology is still relatively new and involves a high level of development work, the market does not yet offer a broad range of devices. The added value of a transmission rate of 10 Mbit/s is also limited for simple digital sensors.

This is why Beckhoff has made the decision to integrate Ethernet-APL technology into their modular terminal block portfolio. The compact ELX6233 can be mounted in the control cabinet in combination with other EtherCAT Terminals. Two Ethernet-APL field devices can be connected via the ELX6233 terminal. As with all EtherCAT Terminals in the ELX series, the ELX6233 enables direct connection of intrinsically safe field devices up to zone 0.

Advantages of the ELX6233 at a glance

Modular and flexible combination options

The Beckhoff system solution allows all EtherCAT Terminals to be interconnected without requiring special tools. The ELX6233 features a standard housing and can therefore be easily integrated into existing terminal segments. When it comes to digitalization, the direct connection to embedded PCs in the CX series in particular offers a whole host advantages, including the ability for gateway applications to process data from the field and filter it before sharing it further.

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Connection of intrinsically safe field devices

Like many of our EtherCAT Terminals, the ELX6233 is suitable for mounting in zone 2 of the hazardous area. What’s more, the special circuitry means the ports offer the highest explosion protection class and allow the connection of intrinsically safe field devices from zone 0. This means the parameters are adapted to suit the specifications of IEC 60079-47 and follow the SPAA port profile.

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Space-saving solution

The ELX6233 allows you to create exactly the number of Ethernet-APL channels you need in your control cabinet. Its compact design not only saves you space, but also costs. And with a width of just 24 mm, the EtherCAT Terminal fits into any application, whether it’s a large process industry plant or a compact test setup.

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Fast communication with EtherCAT

Unlike in many PROFINET architectures, the controller is located directly in the EtherCAT Terminal and not in the higher-level controller. Since EtherCAT enables a more compact data size of the process image compared to PROFINET, the performance can be significantly increased in terms of cycle times. Data security is also higher than with classic switched networks due to the separation of individual ports and protocols.

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Ethernet-APL FAQs

In many applications, Ethernet-APL is to be used alongside existing communication technologies such as HART, Profibus, and digital signals; however, the market does not yet offer any solutions for this kind of mixed operation. This is why Beckhoff integrates Ethernet-APL into the existing terminal portfolio on a modular basis, allowing different signal types to be flexibly combined.

Ethernet-APL specifies various energy levels for intrinsically safe Ethernet based on IEC specification 60079-47. These levels are outlined in the port profile specifications that every APL port in a network must comply with, and there is a clear definition of which ports may be connected to each other. With all of this information available, it is not necessary to perform a separate calculation of the proof of intrinsic safety.