Media Converter Puts Ethernet on Blue Hose

March 18, 2014
Over the Past 20 Years, Belden Has Produced and Sold More Than 391 Million Feet of Blue Hose--Enough to Circle the Globe Three Times--and Much of It Is Still in Use in Facilities All Over the World

The inspiration for ProSoft Technology's new Ethernet to Belden Blue Hose Industrial Media Converter came two years ago at Rockwell Automation's Automation Fair. "A customer came to us with a problem with his Remote I/O system," says Ken Roslan, vice president, global marketing, ProSoft Technology. "Rockwell Automation is discontinuing Remote I/O and has given a one-year notice. Users need to upgrade, but the new Flex I/O requires Ethernet, so they are faced with replacing their network wiring."

Roslan says there are several hundred thousand Remote I/O systems in use, many using PLC 5 and SLC controllers connected with Belden 9463 "Blue Hose" wire. "Blue Hose wiring has been the industry standard for Remote I/O networks," he says. "Over the past 20 years, Belden has produced and sold more than 391 million feet of Blue Hose—enough to circle the globe three times—and much of it is still in use in facilities all over the world."

Save the blue hose

ProSoft Technology's new Ethernet to Belden Blue Hose Industrial Media Converter allows users to upgrade I/O as needed—one node at a time—and move it over to Ethernet.

Typical systems have 1,000 to 10,000 feet of cable. To put in a new control system, plants would have had to add Ethernet using Cat 5 cable and managed switches, with fiber for distances over 300 feet. "Just running the cable itself can be a challenge," Roslan says. "Then they have to convert programs and schedule downtime to install and commission the new system. That's when risk starts going up."

Also Read "Ins and outs of remote I/O deployment"

The new converters allow users to upgrade an Allen-Bradley Remote I/O system by running Ethernet communications over the existing Remote I/O network. "Your cable company runs cable TV and Ethernet over the same coax cable," Roslan says. "We applied that same idea, but over Blue Hose, which is twinax."

These converters support 57.6-K and 115.2-K baud rates, and the units are plug-and-play with no configuration required. "You connect to the Blue Hose and power up. There's no setup," Roslan says. "It's completely transparent, like an Ethernet-to-fiber-optic converter."

The system is tailored for retrofits. "A lot of this Blue Hose cable has been out there for many years, at different lengths and various levels of deterioration. The converters monitor communications, and pick the best broadband channel for the installed condition of the cable," Roslan says.

The converters provide more than the ability to avoid replacing cable. "You can change one thing at a time during a scheduled shutdown," Roslan says. "You can continue to use an old controller while you install a new controller, convert the code, and use a remote I/O card to test the code while the plant is running on the old controller, then switch over."

This approach allows users to upgrade I/O as needed—one node at a time—and move it over to Ethernet. "Being able to simultaneously run Ethernet and Remote I/O lets you make changes with minimal downtime and little risk," Roslan says. "You can upgrade a node and use the old I/O as spares for other old nodes to buy time before you need to replace them. In effect, you'll never have to replace the network cable."

One master handles multiple slaves with cable runs up to about 1,750 feet. As many as eight repeaters can be used to extend runs to 10,000 feet, with as many as 32 nodes, the same maximum network size as Remote I/O. Supporting a minimum of 1 to 4 Mbps, speed is at least 10 times as fast as Remote I/O, and it can handle bursts as high as 20 to 30 Mbps.

That Automation Fair attendee's problem has been solved. "Customers who previewed the product said, ‘You can't do that,' but that isn't true anymore," says Roslan. "It works just like Ethernet over coax; it's just a different technology."

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