I'm designing a network of sensors to be placed in an outdoor environment, see the attached diagram. The network will consist of 30 data acquisition boards (very low power consumption), divided in 10 zones ("Silo bags" in the image). Each zone will be separated by 5m and the Main node (in charge of the communication with a remote server, power distribution and configuration) installed in the middle, so the horizontal wires will have a maximum length of 25m. Each zone have a length of up to 75m (vertical wires) with 3 data acquisition boards in each zone.
I was planning on using UTP CAT5 or CAT6 cables, with 2 conductors for data (CAN bus) and the other 6 for power distribution (3 for GND and 3 for Vcc). The idea is to design the nodes with 2 RJ45 connectors and connect each data acquisition board in a chain. I would also need to design a board with 3 RJ45 connectors as a T-connector for the UTP cables (UTP splitter in the image).
- What do you think about this scheme?
- I know that CANbus is very immune against noise and the length are not near the limits, but can it bring me trouble having so many connectors?
- What about the DC power distribution? considering that the whole system will be powered by a battery placed near the main board (I will make intense use of the low-power modes of the MCUs). What about the power losses?.