Automation Fair: ControlNet fiber optics communication modules for self-healing ring, dual redundant applications
Chicago, IL —An updated family of Fiber Optic Communication Modules for ControlNet self-healing ring and dual self-healing ring applications was unveiled by Weed Instrument today at Automation Fair 2007 in Chicago.
“We’ve gotten a lot of feedback from Rockwell Automation and others in the marketplace,” says Mike Wightman, alliance and channel business development manager, Weed Instrument. Wightman told Control Engineering that this product extends prior Weed ControlNet offerings, with smaller size, better diagnostics, and dual redundancy. He expressed excitement about ControlNet, still growing at a double-digit rate, and offering capabilities that Ethernet protocols cannot. Those advantages, affirmed Scott J. Johnson, product marketing specialists, Logix/NetLinx Business, Rockwell Automation,
The Weed products are calledeed says, communications are still maintained along a secondary path or, in the case of a dual ring, tertiary paths.
Downstream Multicasting transmits an incoming message in multiple directions and insures that while directing the message toward all nodes in the ring it is never retransmitted back to the point of origin. This communication method employs a “Master” or ring control module which will direct traffic and guard against duplicate message delivery. The design eliminates process downtime from an accidental cable break.
Local and remote diagnostic tools are incorporated into each to enhance reliability and support preventive maintenance. These address power input quality, optical fiber fault, location of optical fiber break and link status. Data on the optical fiber lines is constantly monitored. If a fiber fails to transfer light or is broken an alarm activates.
The new modules support the highest number of nodes and deliver up to 60% more optical power than competing models, resulting in the ability to have longer transmission distances between nodes. Requiring only 50% of the space needed by the previous models (which also didn’t offer dual redundancy), the 2C31 and 2C32 are housed in compact DIN-rail enclosures, significantly reducing the required installation space.
Wightman says the new offerings are in place at several key customers and will be available to all in January 2008, after certifications are completed. The Weed booth at Automation Fair showed the technology in use.
Weed Instrument, based in Round Rock, TX, says it is a leading supplier of fiber optic industrial networking modems. In addition to ControlNet, the company offers products for DeviceNet, Industrial Ethernet, Profibus, DH-485, DH+, Remote I/O, RS-232/485, Modbus Plus, analog and digital data links, multiplexers, and contact closures.
For other technologies from the event, read:
Automation Fair 2007: Technologies at Chicago’s McCormick Place .
— Mark T. Hoske , editor in chief
Control Engineering News Desk
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