Electronic – Does it matter which 2 nodes on a CAN bus you terminate


I know you need to terminate the 'ends' on a high speed CAN bus but what if you know nothing about the topology of the network or where the bus will go. For my application i have designed a data acquisition unit for a vechile and want the ability to add nodes to the network as i please. The location of the devices that may be used is unknown so in that sense im finding it difficult to define what the ends of the bus are.

Can i terminate the bus on the same circuit and have connections to the bus through that device

                    [node1]      [node2]
                       |             |
  ------------------(connection to unit)----------------------
                       |             |     
                       [internal node]

Best Answer

Each beginning has its end. This can't be answered, because the question is not correct. What you have is the transmission line - a twisted pair that has two ends, and that's the place where the termination has to be done. You can't choose the end of the bus, since there are only two of them.