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Industrial Ethernet Book 103

TAepcphlincoaltoiognys Effective monitoring systems on wide area networks (WAN) can be created by integrating a combination of field devices, wireless data logging and monitoring software. connectivity outages for small time intervals. At the cloud, the level of information that is to be utilised to achieve the desired needs of the first point. We can now see that there is the possibility to have a distributed management process overseeing the system as we would want much of the data transform to be carried out in the fog. Information rather than raw data is passed up towards the cloud, lessening the required throughput and leaving less to be completed in the cloud which, although having possibly powerful computers may be used by many in a virtual machine environment (to minimise costs) and are more than likely not under our tight control. Let us take another example, in this case one most have encountered in some degree over time, that of aircraft operations. Today this is a good example of distributed control and monitoring as many countries have, or are migrating their airspace management to, a centralised system. Taking two aspects that are important, we have weather and aircraft position. Aircraft only make profit when they are airborne. As an aside, we often think of the hierarchical view of Command and Control as the real world being at the bottom and the overview being at the top. In this case, it is the aircraft that are physically above the control centre so in essence the physical and metaphysical have been reversed. Weather is reviewed on a long cyclic view, as the weather at height is important, not that at ground level, so satellite data is taken in as well weather monitoring stations. It is the aircraft themselves that could monitor their own weather (by radar and pressure sensors) and pass this as a more local and accurate view to the control centres. The centres can then have not only weather information as a 2D object but also as a 3D model. Ground-based radars throughout the country are monitoring the airspace and their data can now be joined to provide 3D positional informational which can be used to check the position being fed from other sensors both on the aircraft itself as well as other external aids. By distributing the monitoring between aircraft themselves, airfields and localised positions, the information provided to central air traffic controllers can be seen to be very accurate and ‘clean’. Notice again, as in previous examples that the fog is providing information forward and not just raw data. Information, a joining and contextualisation of several data points, is being used in preference to raw data. But what can go wrong? The mechanism of providing information has one big disadvantage. The closer to an overview picture we move the information, the more diluted the data gets. Here we are looking at the distinction already described between data and information. Failure in a good way Driving a motor at the correct speed continuously needs accuracy as, in the real world, many controllable and uncontrollable factors can affect the speed; not least of which are power surges, ambient temperature/ moisture changes, friction build up etc. However, monitoring the speed over time can give us an indication of the serviceability status of the motor in that answering the question of the current wear level will show when the motor may fail. We have already discussed that at the edge, or in the fog layer, the processing needs are for accurate, fast computers and introduced RISC computers but Moxa also has Intel Processor based computers which come in several form factors and capable to operate, in some variants in hazardous environments. The V2000A series being targeted at rail transport and DA Series specifically made for the energy generation markets. Alongside these are Panel PC models as well as straight processing platforms in the marine market. Such points then can be used to aid defining the function partitioning; whether to use the fog to process the data or the cloud. The time needed to get information to the cloud and make the decision as to whether the speed is correct may generally be satisfactory but is it efficient enough to actually introduce speed control? The fog would be more efficient to apply the speed control aspect with the 40 industrial ethernet book 11.2017 SOURCE: MOXA


Industrial Ethernet Book 103
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