Suggestions for a FPGA friendly 10 Mbit/s industrial bus ?

[Matthieu Michon]

Hi all


I'm looking at different solutions for connecting a FPGA-based system (hw/fw designed by us) to a industrial controller (NI CompactRIO), and would make use of some suggestions or clues to be sure that I don't get the wrong idea our locked in a dead-end.


The estimated data rate is around 5 to 10 Mbit/s unidirectionnal (FPGA system -> CompactRIO), and maximum latency should be under 1 ms (jitter is not an issue). Cable length


So far I came across the following protocols supported by the CompactRIO:

* Fast-Ethernet
* Profibus

The Fast-Ethernet electrical implementation appears to be more complex then Profibus (RS-485), on the other side the implementation of the UDP/IP/Ethernet stack seems easier (a lot) than Profibus.


At first sight I was about to go with Profibus, however after looking into the high-level layers of Profibus and how to implement them in our system (designing our own Profibus controller in HDL, or using an IP, or even a AM1810), I'm less confident with this solution and starting to think that Ethernet would be better for us.


Does anybody have some thoughts about all this ?


Kind regards
---
Matthieu Michon

 

[Chris Maryan]

Does your FPGA have a built in ethernet MAC? If so, the answer to your question should be pretty clear - basic Ethernet (unidirectional UDP packets) is relatively easy if you have a MAC.

Chris