09 April 2001
Striking up communications with factory-floor Ethernet
New technology brings company into the twenty-first century.
Manufacturing matchbook covers may seem like an ordinary process that wouldn't require sophisticated communications, but to one of Mark Jacobs' customers, it was a process worthy of Ethernet fieldbus communications to improve productivity.
The idea of using Ethernet to improve productivity is just one of the topics on tap for ISA 2001 in Houston this September.
Jacobs, motion control manager at Eastern Bearing Inc. in Waltham, Mass., was commissioned to help his customer, D. D. Bean & Sons in Jaffrey, N.H., develop a process of acquisition as well as machine control. "Before their new Ethernet system, the company was depending on electromechanical machines from the 1930s," said Jacobs. "Back then, before the advent of solid-state technology, electrical engineers supplied the motors, and there was not a lot you could do with them. In those days, mechanical engineers were king." Jacobs explained that the company wanted to connect everything and collect data throughout the entire factory. Jacobs did a market survey of big-name companies and recommended a communications system using Ethernet fieldbus.
The new system adjusts the speed of the machine to the skill of the operator. Jacobs' team replaced a variable pulley with a variable speed drive and developed a database that included the operator. The operator scans onto the machine using a bar-code scanner. The machine looks up the speed of the operator and sets the speed of the machine to the operator's level. "The Ethernet fieldbus is the way we communicate that information to the server," said Jacobs.
Another feature is that the system counts product and records uptime and downtime through a series of timers distributed to each machine. It does this through a polling technique over Ethernet and records information in the database. In the morning, a report tells manufacturers what happened the day before.
Why use Ethernet?
"I started looking up things like fieldbuses because the customer needed to have a fieldbus to collect information," said Jacobs. After surveying all the literature, including Profibus, Modbus, Data Highway, and the like, Jacobs concluded that Ethernet was the way to go. "They needed something that was expandable and supportablesomething that gave them options and that they could use 10 years from now," he said.
Jacobs based his choice on his contention that Ethernet is a common platform that isn't restricted to a certain vendor. "If you use a particular fieldbus from one company, you're fairly well locked into that company's components," he said.
Jacobs explained that there's a lot of equipment on the market that you can connect to Ethernet. "With Ethernet, I can get into a system from anywhere in the world. Of course, you can do that with other fieldbuses, but you have to have fancy modems," he said.
The main advantage of the new system is that it ultimately increases productivity in the plant, Jacobs said. Eventually, it will connect to the company's main office system.
"During the installation," said Jacobs, "I just loaded the software in five minutes, set up the addressing, and within 30 minutes the VP of operations could watch the manufacturing floor in real time. There's no way we could have done that with standard fieldbus communications." IT
Ellen Fussell is assistant editor for InTech magazine.