Rob, this is a terrific article; it points out a continuing significant problem.
The better Etherenet arcitectures I've seen have an outer office-type network that is connected to the internet, a middle level used for supervisory control of the plant, and an inner for machine level control.
IT departments will have to become more agile. Our continuing trend of doing more with fewer people REQUIRES this.
Last week I was in a plant which had a SCADA server stop communicating with plant-floor HMI terminals. The engineer most knowledgable about the servers was out of the building, but used her smart-phone to remotely reboot it and get the floor functioning again.
Her plant did have very good security yet permitted the flexibility of remote access which permitted rapid response to problems.
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