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Do you want to transfer data to a control unit via long, costly and error vulnerable lines or do you prefer using intelligent nodes?
This is a question that has already been solved by the automobile industry. As an answer the CAN-Technology (CAN = Controller Area Network) was founded and developed. Today for example data from the ABS-sensors are not passed anymore onto the control unit (usually placed centrally in the engine room) by every single wheel with a number of specific lines for the different information, but is first locally collected, prepared, digitalized and then passed foreward via an ordinary line. At the same time these intelligent nodes already filter out (after being accordingly programmed) unimportant data existing outside a defined tolerance, so that this information need not be transported and processed by the control unit at all.
The nodes are situated along the line like bus stops at a bus line - that's why it is called Bus-Technology.
Thus a system is created that is less vulnerable against failure and at the same time low on costs. In case of technology changes, sensors and actors can be kept and merely the control unit needs to be re-programmed. Or in the reverse case: New decentral nodes could be set without replacing the control unit.
But costs will also be saved because the used lines are much less cost-intensive. Instead of expensive special lines that connect the nodes with a ECU (e.g. thermo couple lines) simple twisted two-wire lines will do for the digitalized data transfer. The digitalization of analogue data is done already in the nodes. Because of this digital data preparation, local and central - intelligent - protocols for maintaining quality assurance are possible for the first time.
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