Bus Telemetry with Redundancy - non-Tree Networks & Re-Programming via the Bus Cable

Discussion in 'Computing and Networks' started by Ste_Mulv, Mar 17, 2010.

  1. Ste_Mulv

    Thread Starter New Member

    Sep 23, 2009
    Hello there,

    I am planning on trying to build a peer to peer bus telemetry network, based on something similar to the CAN bus, however I would like to incorporate some redundancies, so that if I get a fault on a cable, the telegram can be routed via another cable connection. Currently I can only find Bus standards that operate in a tree topology, which although efficient, is not very good at responding to faults in cabling.

    I have drawn out some topologies that I would now like to start playing with; however my theory goes that each node would have 3 bus couplers creating 3D, multi-area network. I also predict that by utilising all connections, the speed of the network can be increased of around 50% per extra line.

    Does anyone know of a current bus standard that provides this redundancy, or will I have to start inventing? I imagine that this type of redundancy system is in operation in air-craft (that is a hunch) but I do not know which standards are used in the aviation industry.

    Finally, I have recently discovered the wonderful world of KNX, and I am now a convert to the tightening standards to give great usability. The KNX system allows the program to be updated from the BUS, and although the firmware cannot be updated via the bus cable, the parameters can. I have never looked at this methodology before, and I am very interested. My end goal is to start building a roaming robot using distributed process sensing and control... I think this is the systems that a neural network is based on...

    If you have any experience is any of these matters, or even noticed somthing similar in passing,
  2. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    Think of the bus(es) as hardware, eg. the physical transport layer.

    The redundancy would be part of the software protocol driving the hardware.

    You could use any hardware bus that can handle the data you need to move. CAN is probably one of the easiest from that point of view.

    You could also use 'dumb' UARTs and RS485 interfaces to each bus, allowing you to completely design the protocol yourself.

    Overall it looks a bit like you are recreating IP routing, with automatic discovery and weighted fallback routes if the direct one is not available? Depending on what devices you are trying to interconnect, you could just use multiple ethernet interfaces spread over different subnets.