By Jim Montague, Executive Editor
Maybe I’m too easily impressed—or maybe I was hallucinating from missing lunch. In any event, while our videographer, Ginny Austin, and I were innocently shooting a few video interviews at the recent ProMat 2009 material handling show at Chicago’s McCormick Place in mid-January, we witnessed a serendipitous unfolding of the recent history of industrial networking. In short, we saw an initial jump from hardwiring to fieldbus, an intermediate step of fieldbus to Ethernet and a futuristic incarnation of Ethernet and wireless.
First up, Dematic, Grand Rapids, Mich., exhibited its Multishuttle automated storage and retrieval systems (AS/RSs), which combine photocells, powered rollers, servos, software and power supplies from several suppliers and connects all these devices via two digital networks, according to Doug Schrewsbury, Dematic’s principal engineer. “Fieldbus and Ethernet greatly simplify our network compared to the past,” explains Schrewsbury. “Now we have fewer components than a traditional AS/RS, and this makes it much easier to maintain. This simplification also made it easier for us to migrate Multishuttle’s components and reprogram its PLC software, so we could launch it in North America.”
Next, Daifuku America, Salt Lake City, showed its multi-section integrated system, which consists of its large unit load AS/RS combined with two different automatic guided vehicles (AGVs). These include its Jervis B. Webb subsidiary’s Smart Cart automatic guided carts (AGCs) and its SmartLoader 3000 automatic trailer-loading vehicle. Smart Cart AGCs are guided by floor-mounted magnetic tape and transponder tags, which are coordinated by Webb’s CartTools software, as well as its cart management system, which uses a wireless Ethernet local area network (LAN) connection to collect data from all the AGCs in a given area. Likewise, SmartLoader is directed by the firm’s vehicle-system-manager software.
Finally, Kiva Systems, Woburn, Mass., demonstrated its autonomous, robot-based, material-handling system, which includes a squad of self-organizing and self-adapting vehicles. These robots look like a cross between bright orange ottomans and horseshoe crabs, patrolling and pirouetting around a railed-off corral at Kiva’s exhibit, complete with a sign that reads, “Do Not Feed the Robots.” These units can lift 1,000-lb or 3,000-lb shelving units, move them at typical AS/RS speeds of about 1 m/sec and deliver them to pick-and-pack operators as instructed. Kiva’s robots also accelerate and decelerate smoothly due to variable frequency drives (VFDs), and they avoid collision by using onboard proximity sensors. All these activities are coordinated by Kiva’s proprietary Ethernet-based networking software and hardware located on the robots, but mostly residing in its overall management system.
Free from their traditional proprietary straitjackets, some innovators like Dematic, Daifuku, Kiva and their homegrown industrial network solutions finally are getting real opportunities to show what they can do, and it’s a lot more than saving a few wires. Looking back on the recent history of industrial networking, it’s a shame they were held back for so long.
The emerging truth is that digital networks such as fieldbus, Ethernet and wireless can deliver maintenance and troubleshooting benefits and efficiencies far beyond any initial savings generated at installation and startup. Early arguments for adopting a twisted-pair fieldbus focused on initial wiring savings, but these claims often were disputed. This allowed detractors to claim that it wasn’t worthwhile to switch from 4-20 mA hardwiring to a fieldbus. At the time, there wasn’t enough evidence about the longer-term advantages that digital networks could deliver. Fortunately, things have changed, and there’s now ample evidence that digital networks can deliver substantial diagnostics, maintenance and troubleshooting savings, as well as allow more I/O points and devices to be installed in the field.
I guess the main message here is not to wait too long for standards and assurances. Go out and find useful solutions for yourself. The age-old, oft-repeated advice to evaluate your application and its needs, test potentially useful solutions in non-critical areas and then implement the network solution that works best for you was never more true than it is now.