The Ethernet Edge

As technology continues to drive innovations, most machine builders, manufacturers and systems integrators are facing internal pressures to cut costs and external demands for better products and services in order to remain competitive in the market.

In the Asia Pacific region, the use of Ethernetbased, networked remote and local I/O is increasingly replacing hardwired discrete and analog signal installations and becoming standard in industrial automation and control systems.

Over the past decade, manufacturers recognized and took advantage of the cost and labor reductions, as well as improved uptime from faster troubleshooting that Ethernet-based systems provide.

Across all groups involved in the building and implementation of next-generation machines, the importance of high-speed networking and the availability of compliant hardware is a given. Even long-time users of fieldbus networks such as DeviceNet, Profibus, AS-i and Modbus are beginning to shift to Ethernet-based networks. There are many compelling reasons for the transition: reduced labor costs, standardization of one network media type for the entire machine, fewer wiring mistakes, smaller main machine panels, and higher throughput.

According to Colin Soh, product Manager at Omron Asia Pacific, “Manufacturers realize the values and benefits that networked remote I/O brings as a powerful communication system. And in the last three or four years there has been a rapid move away from traditional fieldbus networks to Ethernet-based networks such as EtherNet/IP, EtherCAT and Profinet.

“People have traditionally built with DeviceNet and a base of users and developers continue to do so. However, the growing use of EtherNet/IP on the factory floor is leading to DeviceNet for I/O communications being replaced in new applications,” adds Soh.

Push factors
The advantages of moving from traditional fieldbus networks to an Ethernet-based topology include:
• Reduced cabling costs
Ethernet cable is much less expensive than most other cable choices.
• Fewer wiring mistakes
Pre-terminated Ethernet cables are easier to work with – and less prone to wiring mistakes or improper network power design, reducing inefficiencies that result in delayed machine delivery.
• Standardization of infrastructure
Both EtherNet/IP I/O and Profinet I/O are designed to co-exist with other protocols on an Ethernet infrastructure, so machine builders only need to run one Ethernet network to support remote I/O, HMIs, Safety, Motion and SCADA software.

“From my experience, more than 50 percent of machine builders are using some sort of distributed, networked I/O solution,” says Soh. “A host of networks are available, and networked I/O solutions are reducing costs with OEMs finding it a lot less expensive to buy a networked product upfront than to spend time wiring a non-networked solution afterwards.”

Other push factors include material and physical costs. Over the last two years, the cost of copper has increased by almost 70 percent, making it more expensive to buy wire, which in turn is driving people to remote networked I/O solutions where numerous I/O wires are consolidated into a single network cable.

Furthermore, the ability to use smaller control panels is significant. Larger panels cost more, and customers are expecting machines to have a smaller footprint with increased functionality to reduce panel size. Indeed, many manufacturing facilities are trying to increase equipment density – get more machines into a given space.

As well as requiring less customer floor space, reducing the size of control cabinets also lowers cost. “I've seen manufacturers reconfigure gigantic plant floors to get a higher density of machines on the floor,” says Soh. “These manufacturers are expecting builders to reduce the floor space of machines.”

Product implications
Ancillary to the movement to remote networked I/O platforms are changes at the product level. For example, there is a shift from motion control products (e.g. servo systems, variable frequency drives) being controlled by digital and analog signals to being controlled on faster motion control networks such as EtherCAT, Sercos or Mechatrolink. This change in motion technology provides the machine builder with a number of advantages:

1. Higher machine/motion performance
The coordinated motion control that can be accomplished by using a motion control network allows the machine builder to create a machine with greater throughput capabilities, as well as reduce product scrap during machine startup. Greater machine throughput can be achieved with coordinated motion control over EtherCAT. For example, this Ethernet-based network is capable of updating 40 motion axes in 276 microseconds with repeatability of synchronization within one microsecond.

2. Better diagnostics
When motion control products are on a motion network, any warnings, errors, or other anomalies can be communicated in real time to a local operator, supervisor, maintenance personnel, or other individuals responsible for machine operation and upkeep. This notification can be as simple as a message on a local HMI to an email or text message. Also, if the machine is connected to the internet, the machine builder can access the unit from anywhere in the world and remotely observe a problem in real time, and even take corrective action from the remote location.

3. Faster setup
Network configuration is streamlined through automatic node identification, while multiple remote axes are made much easier to commission, as there is no longer a need to walk around the machine to plug and unplug cables. Saving the configuration after tuning each node is now a much faster process.

Positive ramifications
One market segment where the above movements are particularly pronounced is Automotive, where tier one and tier two suppliers are responding to changes in demand. During the economic collapse, major automotive manufacturers slowed down production considerably; it didn't cease, but their pre-buying from suppliers dropped remarkably. As the economy recovers, these suppliers are seeing an increase in production volume.

Another key indicator is the packaging industry, where builders are under constant demand for cost reduction on machinery. Upfront costs between distributed I/O solutions and traditional direct-wired ones are scrutinized since hardware for distributed solutions is perhaps a bit more expensive, but overall manufacturing costs drop considerably to tip the scale in the direction of distributed I/O.

“Machine builders welcome the change as it lowers their costs and simplifies installation and maintenance. They realize that the cost to manufacture and ship equipment reduces by 10 to 15 percent when using distributed I/O and intelligent control of motion products,” says Omron's Colin Soh.

Numbers such as these will undoubtedly fuel the growing momentum for high performance in industrial automation.

Don Teng is with the Automation System Group, Omron Asia Pacific (www.omron-ap.com).