Just a few years ago, this communication took place via fieldbus and the components were connected to each other using serial communication. However, in recent years in particular, the demands on industrial environments have increased significantly due to digitalization, the convergence of IT and OT and the Industrial Internet of Things (Industrial IoT, IIoT). In order to meet these new requirements, the concept of "Industrial Ethernet" has developed over the last decade.

Ethernet has formed the backbone of IT networks for many decades. Due to its speed and flexibility, traditional Ethernet standards for data communication are also applied to other areas and sectors - including industrial IT. However, the Ethernet concept had to be adapted to the industrial context.

A first step was the development of new protocols for data communication - above all EtherNet/IP, Profinet, EtherCAT, Powerlink or Modbus TCP. A further adaptation - which is the focus of this article - is the development of special hardware for industrial environments.

IIoT devices and their functions

Before going into the details of how the hardware was specified for industrial purposes, here is an overview of the device types used in industry:

• Industrial switches
  These are comparable to switches in a traditional IT network, but are available in more robust versions and can communicate via the usual industrial Ethernet protocols. They are available as managed, lightly managed or unmanaged switches.
  
  
• Industrial routers
  Like their IT counterparts, industrial routers enable the transfer of data between multiple networks, but especially between the Industrial Ethernet network and corporate networks.
  
  
• Industrial gateways
  These devices can be connected to various elements in the production area and are responsible for aggregating data and transmitting it to different endpoints. In addition, they convert communication protocols between different systems and enable communication with public cloud services such as AWS, Azure and Google Cloud.

When it comes to Ethernet hardware, cabling and physical connections are of course also an important basis.

Robust and durable devices required

Industrial environments place completely different physical demands on hardware than office environments. Extreme temperatures, excessive humidity, strong vibrations, high levels of dust, chemical substances and electromagnetic interference fields are part of everyday life in production facilities and factories. Traditional IT hardware would not be able to withstand many of these conditions.

So how is the hardware for Industrial Ethernet adapted to these challenges? Of course, this depends on the environment and the purpose of the installation, but basically the two most important hardware components - devices and cabling - are much more robust.
For industrial devices, there are models that can operate between -40 °C and 85 °C, have increased vibration and shock resistance or offer high IP protection classes.

For cables, it is obvious that the usual 8P8C connection would be inadequate in almost all of the harsh conditions often found in factories and plants. Cables for industrial use are therefore more robust - with higher quality sheaths and metals - and have connectors that have additional shielding or are waterproof.

Specifications of the industrial devices

Resistance to extreme conditions is not the only challenge for industrial devices. As other factors must also be taken into account, these devices have other characteristics such as:

• Compact design
  As space in production facilities is often limited, many Ethernet devices are available in compact versions that can be installed in confined areas such as small industrial cabinets.
  
  
• Network redundancy
  Many industrial devices support functions to create network redundancy. This involves creating additional instances of network devices and communication lines to prevent downtime or data loss. This includes, for example, functions for setting up ring networks or using the Spanning Tree Protocol.
  
• Security
  Security standards that apply to IT Ethernet do not necessarily work for OT, which is why specialized security functions are required. Industrial devices usually offer functions based on IEC 62443, a collection of security standards for industrial environments.
  
• Modularity
  The modularity of the devices is another useful feature. For example, a modular switch with different line and power modules makes it easier to expand or maintain a network without long downtimes.

Bringing Industrial Ethernet into focus

The introduction of Industrial Ethernet brings its own challenges for industrial IT engineers and technicians. Legacy devices that require serial-to-Ethernet converters, systems that need to be migrated to new protocols and the added network complexity are just some of these challenges. And, of course, it is critical that these devices are always active and functioning properly.

The availability and performance of devices and systems introduced with Industrial Ethernet can be monitored in various ways. Just like conventional Ethernet devices, industrial devices usually offer SNMP as a communication option. This protocol can be used to obtain important information about the operation of the devices.

In addition, the data required for monitoring is often available via OPC UA, a widespread standard in industrial IT communication. Other mechanisms that can be used for monitoring include APIs and MQTT. Ideally, the monitoring of industrial devices should be part of a holistic industrial IT monitoring concept.

Christian Gügel, Business Development Manager New Markets at Paessler