
Ask HN: CANBus vs. Ethernet vs. MODBUS - davismwfl
Environment is moderately noisy, think automotive, marine or light industrial.  The requirements are that you need to potentially send the same message to more then one end point.  80% (by volume) of messages are relatively small in nature, say &lt; 100 bytes, a few (&lt; 10%) are as much as 1k in size.<p>Then say as an option you wanted to add reasonable quality video and still images to the same network occasionally.<p>Which topology, physical and protocol infrastructure would you think makes the most sense?  The field is green so no predisposed environment is defined and it is open to definition.<p>Appreciate any feedback&#x2F;input.
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chrisbennet
Have you seen this?

[http://www.ti.com/lit/an/slyt560/slyt560.pdf](http://www.ti.com/lit/an/slyt560/slyt560.pdf)

 _" Conclusion So which interface is best for automotive communications? They
all are—but each for its own purpose. The CAN bus reigns supreme for low-speed
control applications where cost is a driving factor. When bandwidth
requirements move up, Ethernet can step in as an enhanced interface to support
moderate bandwidth requirements. When the highest bandwidth and lowest-latency
link are required, such as for a surround-view camera system providing input
to an autonomous vehicle pilot, then FPD-Link is ready to meet the
challenge."_

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johnson
ModbusTCP can be routed over ethernet, as can the video (h.264/h.265). Video
over Canbus can be a challenge. Only use modbus, if you already have
modbus(TCP) or intend to set up a traditional SCADA system.

