The When, Where and Why of Ethernet

The somewhat manufactured controversy over "Ethernet" versus "Fieldbus" continues to rage on, albeit in a slightly weaker form.  Some months ago analyst firm IMS published a report that seemingly foretold the death of "fieldbus" networks in favor of Ethernet-based protocols.   The issue of fieldbus and Ethernet being mutually exclusive is tenuous at best.  The FOUNDATION fieldbus specification, for example, includes H1 FOUNDATION fieldbus that operates over twisted pair wire and is designed specifically for use with process sensors and actuators.  We also have HSE, which is a high speed Ethernet based network that shares the same fundamental block-based structure of H1.  

A closer look at the data from IMS actually shows greater than average growth in Ethernet-based network node counts over the next several years, while node counts for "fieldbus"-based devices will still represent the majority at the end of the forecast period.  You can read my analysis of the IMS research here.  

This recent article from Control Engineering provides a refreshing perspective to this issue as well, and discusses how application requirements dictate the type of protocol and network infrastructure you should use in your plant.  It's worth a read.