Key points
Once considered a solution that was limited to corporate network environments, Ethernet is fast bringing the concept of future proof communications systems to the world of factory and process automation. But how suitable is Ethernet in the industrial sphere?
Bernd Knöll, International Product Manager at HBM, explains the reasons behind this growth and looks at how appropriate it really is.
As manufacturers seek to improve processes, reduce expenses and improve productivity without negatively influencing the quality of the product, many are turning to Ethernet technology on the factory floor.
Once considered a solution that was limited to corporate network environments, Ethernet technology has proven to be a robust alternative that can now meet the unique and often challenging needs of the manufacturing arena. Using IEEE standards-based equipment, organisations can now migrate all or part of their factory operations to an Ethernet environment at a pace they wish.
Real time reaction
In terms of communication, an industrial application poses real time requirements that do not play a role in other applications; for instance, an email which arrives with a half a second delay in a corporate environment is hardly an issue but such a delay when controlling machinery could lead to potential malfunctions, which could in turn lead to huge cost implications. With this in mind, a reaction must occur within a specified time frame and this is where Ethernet provides a solution!
Corporate vs. Industrial
Widely considered as a logical step, considering Ethernet is an open standard which enjoys a high level of acceptance worldwide, it is worth remembering that although state of the art networks are now standard in the office environment, it isn’t simply a case of applying it to another industry. Unlike conventional Ethernet, the various solutions for real time Ethernet use protocols, components and topologies which are significantly different.
We also need to recognise the particular demands imposed by industrial working conditions that need to be taken into consideration. During production, dust,
humidity, high temperature, shocks and vibrations must all be tolerated, so components must be able to work under significant stress and in a wide range of ambient conditions.
Measurement technology
Another factor to take into consideration is measurement technology. Frequently used in machines and plants during industrial production processes, the spectrum here is extremely diverse.
Ranging from simple signals with low frequencies to more complex measurement data, the spectrum of tasks is broad and this is where fast connection, as offered by Ethernet, is a significant advantage, particularly where very large data volumes occur during measurement tasks.
Furthermore, if the measurement technology used needs to be integrated in a higher level control architecture, for example based on PLC, appropriate hardware can be utilised to provide the appropriate communications options.
The PMX measuring amplifier system from HBM is equipped with an interface card (PX01EO) for EtherNet/IP, one of the most commonly used automation protocols in the world for programmable logic controllers. This makes it possible to use PMX in many areas of machine and factory automation as a slave module in EtherNet/IP networks.
A universal step beyond traditional network installations
Compared to traditional network installations, Industrial Ethernet networks that use intelligent switching technology can offer a variety of advantages. Providing both plant control and office data capabilities, manufacturers are now starting to reap the benefits of Industrial Ethernet, which include easy integration of shop-floor to top-floor systems and the opportunity to use a single network infrastructure for several different functions, which in turn enhance performance.
In addition to universal communication, Industrial Ethernet also offers the added advantage of a very high bandwidth that makes it possible to transmit even larger data volumes than ever before, at a very high speed.
A universal system also offers notable advantages with regards to maintenance, back up and engineering. Laying the foundations for possible future enhancement, a system with open communication interfaces can also often be cost effectively updated, without the need for comprehensive modifications to the hardware.
However, as you would expect with the introduction of any new trend into the marketplace, there have been certain criticisms linked to Industrial Ethernet technology. Predominately, the biggest argument being that off-the-shelf commercial Ethernet and IP solutions lack the degree of determinism and predictability required for industrial control.
However, in response to these perceived shortcomings, several Ethernet and Ethernet based systems have been developed specifically for industrial applications. EthernetIP, for instance, offers the flexibility of standard Ethernet, which takes advantage of today’s Ethernet technology without resorting to modified switches, silicons and stacks.
Weighing up the options​
Lastly, the actual system environment is something that needs to be fully understood; for instance, will the automation system be integrated, connected or isolated from the IP system?
The migration to Ethernet in manufacturing environments has been growing steadily for years and according to a recent ARC Advisory Group study, this growth is expected to continue at a rate of 84% over the next five years. To reflect this, companies are quickly beginning to recognise the many benefits Industrial Ethernet can deliver.
Whilst it may be argued that Ethernet within the industrial sector does not offer all of the features of a purpose built control network, it is arguably a versatile system which can open the door to a wealth of opportunities designed to increase productivity, reduce assembly and maintenance times and enhance the level of process transparency.
In short, a well implemented Industrial Ethernet network can provide greater control and enable companies to more closely link their internal data networks with the factory floor to make the entire company’s operations more efficient.
Industry standard in measurement technology, PMX supports current industrial Ethernet technology and integrates seamlessly into modern production plants and enables the measurement, calculation and automation of data in real time.
Despite the rapid migration to Industrial Ethernet technology, the decision to switch from a purpose built network should not be a decision which is taken lightly nor based on the simple fact that ‘we need to move with the times’. Instead, various factors need to be taken into consideration to understand the actual need and more importantly, the actual benefits of the system.
Firstly, what exactly do you want to achieve? Is the installation actually suitable for instance, will it be under or over specified? Also, from a performance perspective, how much data will be carried over the network and how fast it will change will have a big impact on its architecture.
