Wire, Cable, and Connectors are Crucial

As the use of wire and connectors increases with added networking functions and interoperability -- and decreases, as networks simplify -- cabling has become forever crucial in industrial networking applications.

By Jim Montague, executive editor, Control Design, and Jill Russell, managing editor of digital media, Food Processing

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With all the cool stuff happening in industrial networking, hardware can be easy to overlook. Wireless and Ethernet seem to be taking over the world. Interoperability is advancing everywhere. Fieldbuses are reaching into intrinsically safe areas. Sensors and transmitters are getting their own web servers. Plant floor and enterprise systems are linking up.

Wires and related components just lie there. Not very exciting.

So, who cares about cables, connectors and cordsets? Everyone. That is, everyone who knows networking hardware still forms the backbone of their control, automation and manufacturing applications, and quietly will continue to enable every rookie networking method that emerges in the future. Point-to-point 4-20 mA still dwarfs all other industrial networking methods, though twisted-pair fieldbuses and industrial Ethernet have scratched its surface lately. And, truth to tell, there are some pretty historic shifts occurring among the cable and connector sectors themselves.

Tailoring Cordsets

Faced with smaller, aging staffs and high labor costs, many end users are asking cable and connector manufacturers, systems integrators, or assembly houses to build more and more complex cordsets for them. As a result, more assembly work reportedly is being outsourced to lower-cost labor centers worldwide. Frank Koditek, Belden CDT's industrial market manager, says his company has seen a big increase in user demand for pre-made cables and connector sets, and that more assembly businesses have grown up to serve that need.

In fact, Jack Gayara, Lapp USA's connector products manager, claims that his firm's custom cordset and wiring harness division has seen double-digit growth in the past couple of years, though business has leveled off in the past several months. "This is a very cyclic business," says Gayara. "When business is booming, then OEMs keep their cordset building in house. When the economy is down a little, they outsource that work."

Five or 10 years ago, adds Gayara, there was a lot of relay logic in control panels, so the wires going to the machine had higher pin counts. "Then PLCs combined a lot of that wiring, and pin counts went down," he says. "Next, newer technologies allowed users to control more functions, and pin counts when up again, until they were reduced by users implementing fieldbuses, Ethernet, and wireless technologies. It seems that cable and connectors' contacts increase; someone finds a way to simplify, and they decrease for awhile; and future technology allows more monitoring and control functions, and pin counts go up again. These two forces really do seem to balance off each other."

Ed Nabrotzky, industrial communication general manager at Woodhead Industries, says increasing use of tailor-made cordsets is part of a trend it calls "connectorization." "Hardwiring usually requires a skilled, union electrician to pull wire, screw on connectors, and address many power and compatibility issues, " says Nabrotzky. "Preassembled cabling and connectors, or 'softwiring,' means less skilled labor is needed, enables more modular design practices, and allows worldwide shipping and servicing far from where components were originally sourced."

In the past, machines often were designed as one unit. "Now, we can break designs into sub-machines and/or sub-assemblies, and mix and match components as needed by the recipe for the product being produced," adds Nabrotzky. "We can build a machine in Kentucky, and reassemble it in Eastern Europe."

This increased use of customized, modular technologies doesn't stop at the cable. Individual connectors also are multiplying the variety of inserts and contacts to meet increasingly varied demands. "People are using more rectangular connectors with different housing or hoods on the ends, but now we even have modular inserts within them, so we can custom configure for specific applications," says Gayara. "It's a lot like Legos. Many users seem to enjoy doing their own inserts. We've even added Ethernet to these modular inserts, which gives some flexibility, but maintains a reliable, shielded connection."

For food processors, sanitation takes precedence. Remke is providing solutions with its series of connectors, interconnects and wire management products. Its connectors are designed to withstand moisture, washdowns, caustic materials, chlorinated cleaners and temperatures felt from flash-freezing to fast baking.

It's Tuff-Link series of interconnects combine stainless steel, non-metallic or nickel-plated components with gold-plated contacts, while its Tuff-Seal products use stainless steel, Valox or nylon with nickel-plating to ensure top connectivity and corrosion resistance.

Though much cordset assembly is outsourced, some manufacturers are finding they can do it themselves economically. "We do a lot of assembly work here, rather than sending components to two or three other companies before they reach the end user," says Kirk Larson, Turck's project engineering manager. "We're also seeing work come back from Asia because of quality and lead time. We're finding we can be competitive in this area."

Ethernet and M12

Though its presence is still small compared to legacy industrial networks, Ethernet is gaining nodes quickly, and this is fueling demand for Ethernet-based cable, connectors and components that can survive and serve long-term in harsh industrial settings with high temperatures, corrosive fluids, electrical noise, extreme heat or cold, high vibrations, or a combination of these factors.

"Presently, Ethernet only makes up 3% of our cable and connector businesses, but that's up from zero just a couple of years ago," says Nabrotzky. "For example, we have the global contract for General Motors' networking, and they've specified having Ethernet in all applications by 2007."

Despite this push, Nabrotzky adds, automotive production suppliers such as robotics and transfer line manufacturers are still having some problems getting all their devices up and working on Ethernet. "The big vendors say they have a working network safety standard in place, but the drives and robotics guys still are asking how to build these standards into their devices," says Nabrotzky. "When they try to do it, they find that everything isn't defined, there are a lot of gray areas, and they have to guess when they try to format a data packet or interpret a signal. There are still a lot of incompatibilities."

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