[etherlab-users] EtherCAT: bandwidth question

[Richard Hacker]

On Monday 18 July 2011 08:32:50 Friedbert Widmann wrote:
> We are discussing about a embedded system that should gather a lot of data
> channels from several EtherCAT devices (slaves).
> We will achieve a bandwidth for raw user data of approx. 2MByte/s.
That is no problem.

> The application in the user space should read this data, reorganize them
>  and send them with a proprietary protocol over another ethernet interface.
> 
> We plan to use an embedded linux and a EtherCAT master library (like IcH
> EtherCAT Master).
> And now my questions (I am a newbie to the EtherCAT technology):
> What are the minimum hardware requirements to meet this plan?
> Do you believe that a small embedded linux will meet this requirements?
>   (modules with freescale MPC5200, 400MHz, 100MBit eth nic, ...)
> Where are the bottle necks in this system?
We do not have any experience with these kinds of systems.
Bottlenecks may bus technology with which the NIC is attached to the CPU. On a 
PC, DMA is used, which is very fast. Otherwise you should have a try and post 
your experience ;)

Here is a paper of someone who has ported the master to an embedded system:
http://www.scientific.net/AMM.34-35.961

Mit freundlichem Gruß

Richard Hacker

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