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Insights on industrial networking

Industrial networking has come a long way and engineers must now choose whether to use a managed or unmanaged switch.

By Jack Smith February 7, 2021

As we begin this new year, I find myself looking back over the many years I have been in industrial automation. I remember working at a company that did contract electronic manufacturing. It introduced its local area network (LAN) for data collection in a printed circuit board testing application. The dedicated LAN was the original 10BASE5 Ethernet, which used coaxial cable as a shared medium, which was prone to data collisions. Computers on the network tried to communicate sharing the same coaxial cable. Determinism wasn’t in the industry’s vocabulary back then.

The industry has come a long way since. What was once a coaxial cable main backbone is now either twisted pair or fiber optic links, either used in conjunction with switches. Whereas data collisions were commonplace, switches make them a thing of the past. Now, for the industrial environment, the choice is not whether to use a switch, it is which type of switch to use: managed or unmanaged.

In this issue of AppliedAutomation, the author explores the topic of managed and unmanaged switches and how to choose between them. The first – and obvious – difference is cost. However, performance increase comes with the cost increase. There are many things a managed switch can do that an unmanaged switch cannot. But users may not need the enhanced performance for some applications. So why pay more? The author looks at how designers can determine if they can make do with an unmanaged Ethernet switch, and when a managed switch is needed.

According to the author, the most common situations where a managed switch becomes necessary are when there are requirements for enhanced traffic filtering, network redundancy, comprehensive security, deeper troubleshooting and diagnostic information, overall better network “awareness” for users and automation platforms and/or any combination of these.

The author said: “Unmanaged switches are certainly suitable and economical for connecting a few devices together with an understanding of low priority networking limitations. However, for many automation applications, the cost increase of moving to managed switches over unmanaged switches is not a major impact.”

Jack Smith
Author Bio: Content manager, CFE Media