Most industry pundits believe it is only a matter of time before we will truly have ‘Ethernet everywhere’ and what that might mean. Other than the obvious increase in bandwidth and difference in power available via PoE what new measurements and sensors might now be possible? An obvious option of a high bandwidth application is process analysis. However not all process analysers require high bandwidth. Gas Chromatographs with their minute plus measurement cycle (each sample injection starts a short batch operation) do not qualify – at least not for the PV, but what about spectrometers? A spectrometer basically exposes the sample to a light source and then measures the reflection or transmission typically on a diode array. This array is then scanned, ‘averaged’ and processed in other ways to provide the process signal normally in a rather large enclosure because of the associated electronics to do the signal processing. However, as just stated the working parts consist of a light source and diode array. PoE makes it possible to place a spectrometer in a ‘puck’ form factor, much like is done with temperature transmitters mounted in the thermocouple head, and do the processing for several of these remote spectrometers in a single central processor up to 100 meters away from the sensor head. Minimal processing is required at the sensor because the 100 Mbit Ethernet makes it possible to transmit the ‘raw data’ to be analysed (analyser part of the process analyser) elsewhere.
What do you think PoE and Intrinsically Safe PoE (also available) might now be within the realm of possibility?
P.S. Remember, that wireless whether it is Lo-PAN or one of the industrial protocols is simply another form of Ethernet but without a tether and like just described above we need to think about what we might be able to do with wireless that we cannot do today, not doing the same things and hoping for different results.
