With the increase in number of electronic circuit units(ECUs) that are connected in a network, the complexity in designing the supporting software increases. It is required to take into consideration the example of parking sensors for effective realization of the complexity involved in designing a system which works in real time. Let us suppose we have eight parking sensors, 4 in the front and 4 in the rear. Each sensor is an analog device which continuously transmits radiations and when there is any interference in their field, the sensors output is varied.
While there is no interference in the field of the sensors, the output of the sensor is constant. But when there is any interference, the output of the sensor varies proportional to the distance between the object and the sensor. But as this is all in terms of analog voltage, there is a requirement for a digitization of this data provided by the sensors. There by use of an ADC is eminent. The resolution of the ADC is the main concern of the system as it is a serial communication protocol.
If the ADC is an 8bit, then the total bits required for complete 8 sensors would be come 64 bits. With increase in the requirement for the sensible systems, the 8bit ADC might need to be replaced by a 10bit ADC or 16bit ADC, which in turn increases the total number of bits required for a single functionality from 64 bits to 128 bits. This takes up a lot of space and time in the channel. But with the CAN protocol we can make this transmission rate much faster by setting the priority to the sensors and then masking all the other ECUs at the time of parking.
All this can be done using the link layers and physical layers of the CAN protocol. The integration of several ECUs to a single network requires a controlled monitoring and reception of data from all the nodes. A central controller can be used to store and access the data from each node and according to the data; the required control of required nodes is achieved. When the engine is heated above the normal range, the controller needs to start pumping the coolant much faster so that it can cool down the engine before starts working abnormally.
Also the control unit needs to have flexibility of including any new MCU, which might come into the market. This flexibility solely lies on the networking the newer nodes with the control unit. Any complicated network with in a limited space can be easily done using CAN protocol and the individual Identifications are allocated to each node in the network, thereby increasing the reliability and secure data transfer between the control unit and the individual nodes.
