At that time, an individual wire was run from the programmable logic controller (PLC) input or output module point to the field I/O device or to each motor starter in a bank of starters. This could amount to miles of wire on a large machine or machining line. So there was the cost of the wire, the cost of the electrician to run the wire and make connections, and the cost of cable tray, wire duct and other peripheral components.

As networks began to reach critical mass early in this century, talk turned to the many other benefits gained. It’s not just wiring cost, but the intelligence that comes along with a network. This is especially true for Ethernet, which can leverage for industrial use the diagnostic tools developed for information technology professionals who have been installing Ethernet for corporate systems for years. Standard Ethernet switches have built-in management tools, in many cases, and finding a tool such as simple network management protocol (SNMP) make set-up, commissioning and maintenance of an industrial Ethernet network relatively easy.

Remember when you would get odd looks from people when you talked about Ethernet on the factory floor or in the plant? No longer.

For an interesting and informative Webcast, “Ethernet-Based Industrial Communication Protocols,” please visit www.automationworld.com/webcast-5345.

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