Hits and Misses for Industrial Ethernet

Industrial Ethernet has made a distinctmark on factory networking, but now we'll see how far that dominance
extends into every facet of industrial machine control and communications. Though thereis still ample room for application growth, Ethernet has clearly reached the mainstream as a solution for monitoring and data acquisition, machine control and remote connectivity.

But the jury is still out on how much it will dominate inreal-time Ethernet applications such as high-performance, multi-axis motioncontrol, as well as in lower cost devices such as sensors and process controlautomation.

"The advances in the Industrial Ethernet market have beentempered by the impact of the recession particularly in segments such asmachine building where real-time Ethernet is crucial in applications such asmotion control," says Chantal Polsonetti, vice president of advisory servicesfor the ARC Advisory Group, whose focus areas include industrial Ethernet anddevice networks.

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"In 2008 and 2009 we saw slower growththan expected but, as you've probably seen from the financials, 2010 was agreat year for customers and suppliers," she says. "One of the key issuesfacing industrial Ethernet now is product availability and the need for moredevices that are compatible with industrial Ethernet, particularly at thedevice level."

Protocol Selection

The selection of an Ethernet protocol is most heavilydependent on what is driving the bus. Machinery builders and users of real-timeEthernet need deterministic operation and time synchronization such as IEEE-1588.Some companies are driven by vertical integration requirements, where internalIT policy carries over to the plant floor and there is a desire for a singlenetwork to be supported throughout the organization.

In a recent DesignNews survey, when asked what network protocols they work with innew designs, responses lined up reflecting the influence of the major controlsystem suppliers in North America. EtherNet/IP (51.5%), native TCP/IP (49.5%),Profibus/Profinet (24.7%), Modbus TCP (24.7%), DeviceNet (23.2%), CANopen(15.5%), Ethernet Powerlink (13.4%) and EtherCat (8.8%) all receivedsignificant support.

"Support for a protocol by the primary control systemsupplier is paramount, and typically a third-party device manufacturer will getinto an installation by supporting the primary control platform provider'sprotocol," says Polsonetti. "If an OEM machine builder wants to put in areal-time network such as EtherCat or Powerlink at the machine control level,they will put in a gateway to get the machine onto the factory network."

Other selection factors include the ability to meetcustomer-specific requirements, such as drives for web handling or other morestringent application requirements, and the IT organization's role in theselection process.

Application and Development Challenges

In terms of industrial Ethernet's impact on applicationswithin the factory, there is no doubt its presence is being felt particularlyin the areas of monitoring and data acquisition (67.7% of survey respondentsclaimed such use) and remote connectivity, maintenance and monitoring (51%). Design News readers also reportedsignificant use of Ethernet for machine control (54.2%), but the overall numberdropped significantly for higher performance applications such as multi-axismotion control (14.8%). Use of industrial Ethernet to connect machinery tomanufacturing operations software (such MES) and business systems totaled 30.3percent. While the technology has made a big impact on operations already,there is also significant room for growth and expansion of network-basedautomation control solutions.

"Industrial Ethernet is becoming thestandard at the controller level, but that is much less true for the devicelevel including I/O, HMIs and drives," says Polsonetti. "When looking tointegrate sensors and lower end devices, which are typically inexpensive andmay not be microprocessor based, the penetration of Ethernet into those kindsof devices
remains a question."

"I'm personally interested to see whathappens in process control. Certainly the hazardous areas are out of thequestion for Ethernet use, but how far it gets into the device level is yet tobe determined," she adds.

As more companies pursue enterprise integration, it's thecommonality of Ethernet networks for the end customer that makes it attractive.Key internal drivers, especially with the larger manufacturers, include theirskill and knowledge base, as well as familiarity with the technology versusproprietary networks which may have limited support.

ERP requirements are also importantbecause enterprise level software can create a demanding challenge in terms ofits data needs. ?As a result, industrial Ethernet is potentially a keyenabling technology across the board from production scheduling, to supply chain,to inventory management and all of the enterprise level applications.

According to the Design News survey, the main challenges and concerns about usingIndustrial Ethernet for automation control focus on managing the network'shardware and software infrastructure, reliability and performance. More thanone-third of all respondents cited management of the physical network (41.9%)and software network configuration (32.3%) as key concerns. Almost an equalnumber focused on real-time control performance (34.8%), network performance(30.3%) and reliability (35.5%) as primary challenges. ?The finalbig concern is in the area of security (33.5%).

The main Ethernet application interest within process control is at the controller levelto link the controllers, I/O and HMIs. Beyond that, time will tell how farwired Ethernet plays out in this industry given the alternatives and high levelof interest in the process industries for wireless technology. This high levelof interest in wireless is key to process industries because the large numberof field devices, outdoor installations and applications that tend to covermore physical area in those industries.