Machine and Process Management

3 reasons to use Ethernet as your industrial communication protocol

I would like to discuss the benefits of using Ethernet as backbone for automation control systems. It’s a technology that enables controllers to connect to this powerful medium.

There are plenty of values in using Ethernet as an industrial communication protocol, but for the purposes of this blog I will focus on three key benefits…

The 3 values I would like to discuss are Ethernet:

  • Openness
  • Transparency
  • Flexibility

Openness:

For me, Ethernet openness is the ability to mix different application protocols on the same media.  These different application protocols provide different services to best fit with a business’s operational needs.

For industrial communication, the ODVA (Open DeviceNet Vendors Association) specifies Modbus and Ethernet industrial protocols to enable communication between controllers or between controllers and operational visualization where determinism is a must.

On the other hand, during operations there are other needs such as diagnostics, time synchronization or IT connection. Using Ethernet will allow businesses to use existing standards such as web based diagnostics over HTTP, time synchronization with NTP and IT connections over web services.

From a business standpoint this openness means a cost effective solution and freedom of manufacturer selection.

Transparency

Ethernet transparency is also a key point and a great technology benefit. The drawback of this transparency is the administrative requirement to ensure security of your network to avoid intrusions. This being said, being able to securely access, your data from everywhere on your intranet has lots of advantages. I will point out two:

Process automation has a huge impact on the energy consumption costs for a company. Having Ethernet on process units at a lower plant level will help to access data straight away, without the need of middleware. Data consolidation will also enable businesses to manage and forecast their energy consumption, and at the same time decrease it without infrastructure evolution.

Schneider Electric, Automation

I pointed out the need to connect the control system to the IT world; Ethernet is the IT protocol so the control system is, de facto, integrated with your IT intranet. The transparency of Ethernet will help businesses to have agile operations by directly connecting manufacturing execution systems with no additional development costs.

There are plenty other advantages to access data from control systems at higher levels of the enterprise such as asset management, production data, remote maintenance, evolution and much more. As I pointed out, there is an administration cost to manage the security of your installation and to maintain it. But Ethernet will avoid the need to develop specialized middleware for energy management or MES connections, for example. The maintenance will only occur at the network level and does not need to be dedicated to specific areas by specialized teams.

Flexibility:

Nowadays Ethernet allows different topology over different media. This flexibility helps to complement plant topology at the right cost.

The bus topology will provide low cost connection, with a daisy chain feature, where availability is not mandatory. The use of fiber optic cable will enable a long distance network whilst retaining a high bandwidth.

When designing the topology, it can help to have distributed device from a single part of the plant. Star topology can be used to secure network devices with critical data, thereby avoiding “man in the middle” attack (where a cyber attack is aimed at the communication between the endpoints on a network).

The ring topology is a typical architecture in automation, as most of the time network availability is a requirement and designed to allow at least with one fault tolerance.

The ability to mix those topologies within a plant helps operations managers to adapt network layouts within physical and availability requirements.

To conclude, an Ethernet backbone increases the agility of an enterprise’s operations. It enables evolution without any change on the infrastructure itself. This being said we understand that having a controller that is fully Ethernet enabled will reinforce all of those advantages.

Watch this video to find out more about an Ethernet enabled PAC


3 Responses
  1. Eric Bonsignour eric

    Very interesting informations Jerome.
    When I remember 10 years ago the begining of the Eth for industry deployment, I’m amazed by how much this is now obvious to most industrial managers !
    – According to you, what would be the specific benefits for segments such as F&Bev, WWW, MMM applications ?
    – According to you what are the key value diferences between a ring, star, daisy chain, daisy chain loop topologies ?
    – What will be the values of a RIO vs DIO architecture for you as one of the best specialist of this matters ?

    Great to lean for you as usual Jerome 🙂

    Reply
  2. Jérome Petit Jerome Petit

    Hello & Happy New Year Eric,

    To answer shortly to your questions:

    I think using Ethernet is valuable in any kind of industry, but for example in MMM & WWW where application are by definition distributed on wide area advantage is to easy access different media communication such as fiber or wireless (Wi-Fi, 3G…). In F&B it avoid having middleware or gateway to connect IT or production software so it reduce maintenance effort in operation.

    Ring & daisy chain loop bring availability on your network, daisy chain reduce connection cost as no additional switch is needed (and no configuration of your switch as well). Start can be used to match with your plant topology.

    Regarding Ethernet Remote IO, the main advantage I see is pre-configured switches that manage two communication flows, on real time for Remote IO and best effort services for Distributed IO. In other words the ability to share on the same media (the PLC backplane) your IO with cyclic exchange and devices.

    I hope it answer to your questions
    Jerome

    Reply
  3. Sam Brown

    Ethernet has landed it way into control and process applications because of it flexibility and adaptability. More and more products are becoming ethernet “ready” too because of the already established communication protocols available. As a common example it’s almost impossible to buy a TV that doesn’t have a network port(RJ45) on the back or WIFI(IEEE802.11a/b/g/n) ‘ready’. This allows the TV to connect to the network, for internet access, watching movies over the internal network or streaming music/movies from external source.

    Ethernet (IEEE802.3) is a transmission protocol and is so beneficial because it runs under the Protocol suite TCP/IP (Transport Control Protocol/Internet Protocol). Under these 2 protocols (using virtual port numbers in software for active equipment) all other network protocols are implemented eg FTP, SMTP, POP3, VOIP, SSH, HTTP etc. These protocols and many more allow for all communications over a network be it LAN or WAN.

    We’re finding that most of the buildings in the city (of Perth) have networked metering. This allows the building manager monitor separate metering for all tenancies throughout the building, from one central location, rather than having to walk around and manually record how much power has been used. Again all meters are usually connected through an ethernet network.

    Lighting control is another example. While most of the modern lighting systems installed in commercial premises run DALI as the control protocol for the lights. The control equipment usually has a backbone network over ethernet, allowing building/facility management control lighting, test emergency lighting, generate functional reports and displaying corrective actions required. Therefore reducing the amount of manual testing and reporting thus keeping costs down.

    All made possible through Ethernet. Ethernet 100BASE-T/1000BASE-T/10GBASET ie 100MB/1GB/10GB runs on 4 pair copper cabling like UTP, FTP, S/FTP up to 100m. Fibre optic is used for distances greater than 100M. So depending on the equipment to be connected, the bandwidth required to run the equipment and distance from the source will depend on the type of cable required and connection type but Ethernet common to all.

    Reply

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