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Keeping Network Systems Healthy with Diagnostics
 Ethernet provides a number of diagnostic capabilities.
When engineers at Automated Interface Solutions go into sheet goods production facilities to install gauge systems, communicating with some of the commonly used hardware often poses a big problem. Installed equipment uses a range of systems, forcing engineers to employ gateways that don't help achieve the goal of increasing productivity and precision.
In a recent installation that mirrors many others, the gateways were already a source of headaches, causing many shutdowns. The AIS customer that produces an array of polypropylene-based products wanted both improved quality control and enhanced reliability. That meant AIS had to fix the networking problem.
“In the old system, the networking schemes were mostly serial links, with data that had to go through custom-built gateways. There were a lot of issues with reliability that resulted in many thousands of dollars in lost productivity,” says Glenn Wrightsman II, senior software engineer at AIS.
The Terre Haute, Ind., system house had to resolve that while adding its sophisticated systems, which constantly measure the weight, moisture and thickness of sheet goods. They turned to Ethernet, extending it down to the input/output (I/O) of its measurement system. Reliability issues disappeared and AIS realized benefits such as simplified installation. “We use an Opto 22 package that's very dependable and has a low cost per I/O point,” Wrightsman says. “It's very easy to use and you can put a rack of I/O anywhere in the plant.” Opto 22 is an automation supplier located in Temecula, Calif.
These simplified installations and improvements in reliability are key reasons that a growing number of system integrators and plant managers are extending Ethernet down to the I/O level. Leveraging the popular network also drives down costs, both during installation and over the lifetime of a system.
The long-term savings come in part from simplified diagnostics that help AIS customers and many others reduce downtime. Ethernet gives users more insight into the health and usage of their equipment, reducing failures and improving productivity. These diagnostic tools, like the network itself, leverage the huge consumer and business base, which drives costs down while bringing benefits such as ease of use.
Searching for simplicity
When companies replace fieldbuses with Ethernet, the payoffs continue well beyond the initial installation. Ethernet comes with a wealth of diagnostic tools that help keep equipment running efficiently. The vast array of troubleshooting tools gives technicians more options than they have with fieldbuses. At the same time, technicians know that upgrades will continue. Everything connected with the network is within the mainstream ...Read more
Gather Copious Information
Though troubleshooting is a critical aspect of diagnostic tools, fixing problems isn't the only reason that engineers want diagnostic data.
Often, information is gathered to determine when routine maintenance should be performed. Diagnostic data also helps tell operators and managers how efficiently their production lines are flowing.
As managers strive to improve efficiency and reduce downtime, the ability to gather more diagnostic data without impacting production becomes increasingly important. The speed and high bandwidth of Ethernet makes it possible to collect data while still delivering all the instructions needed to keep equipment running. That's a major improvement over slower fieldbuses.
“One of the things that comes with Ethernet buses is high throughput, which lets you transmit a lot of diagnostic data,” Stephan Stricker, product manager at B&R Industrial Automation Corp., an Austrian automation supplier with U.S. headquarters in Roswell, Ga., says. “With most fieldbuses, you can't get much diagnostic data because the bandwidth is taken up by user data.”
The ability to move lots of data over Ethernet makes it possible to collect data from every connected point on a machine.
“With EtherNet/IP, you can see exactly what's happening with a device, getting up to 500 parameters that can all be sent to the controller. Ethernet packet sizes are larger than packets in many industrial architectures, so you can send more data,” says Brian Oulton, networks business director at supplier Rockwell Automation Inc., in Mayfield Heights, Ohio. EtherNet/IP is an ODVA specification that blends the network with industrial protocols.
Though Ethernet provides far more bandwidth than older fieldbuses, there are still applications for which additional speed is needed. Most input/output (I/O) devices don't send or receive huge files, so conventional Ethernet links provide more than enough bandwidth.
But when large facilities with many complex machines consolidate on a single networking architecture, the need for speed increases. Developers of the CC-Link network are finishing up a high-speed version that focuses on fieldbus applications.
“CC-Link IE FieldNet will bring the Gigabit speeds of Ethernet down to the device level,” says Chuck Lukasik, director of the CC-Link Partner Association, in Vernon Hills, Ill. “That's 10 times faster than the 100 Megabits competing Ethernet networks are running at now. When you've got hundreds of thousands of devices on your network, you need that speed.” ...Read more
Network Intelligence: Opening the Door
When the subject of networks was first broached to control engineers in the early 1990s, the whole pitch was about saving money on wire.
At that time, an individual wire was run from the programmable logic controller (PLC) input or output module point to the field I/O device or to each motor starter in a bank of starters. This could amount to miles of wire on a large machine or machining line. So there was the cost of the wire, the cost of the electrician to run the wire and make connections, and the cost of cable tray, wire duct and other peripheral components.
As networks began to reach critical mass early in this century, talk turned to the many other benefits gained. It's not just wiring cost, but the intelligence that comes along with a network. This is especially true for Ethernet, which can leverage for industrial use the diagnostic tools developed for information technology professionals who have been installing Ethernet for corporate systems for years. Standard Ethernet switches have built-in management tools, in many cases, and finding a tool such as simple network management protocol (SNMP) make set-up, commissioning and maintenance of an industrial Ethernet network relatively easy.
Remember when you would get odd looks from people when you talked about Ethernet on the factory floor or in the plant? No longer ...Read
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