[etherlab-users] example code

Jeroen Van den Keybus jeroen.vandenkeybus at gmail.com
Wed Nov 20 17:34:16 CET 2013


Using Xenomai and the specific patched drivers, I could easily go beyond 10
kHz with an EK1100 and 2 EL2008 on a Core 2 Duo 2.2 Ghz with e1000. I also
did extensive measurement of delays and came up with about 6.5 us for the
IgH master and something in the order of 10 us for the NIC from transmit
start to first symbol on wire and back (last symbol on wire to receive
start). So the NIC delays are certainly appreciable as well.

Are you running stock Linux (e.g. no RTAI, Xenomai or RT-PREEMPT) ?


J.



2013/11/19 Curt <cfiene at cybermetrix.com>

> Sorry for the newbie questions.
>
> I've downloaded built and installed the ethercat master 1.5.2.
>
> Used the generic driver to communicated with an Beckhoff EK1101 hub, EL1034
> digital input and EL2034 digital output.
>
> I then modified the ./example/user/main.c code to work with these modules.
> Seems to work OK.   I then  looped the digital out to a digital in to some
> basic performance testing.
>
> At a update rate of 1kHz (1 millisecond), it can detect a change on
> average of
> about 2 ms.    I increased the rate to 2kHz,  it can detect a change on
> average of 1ms, BUT, I see an occasional, "EtherCAT WARNING: Datagram
> da69fecc
> (domain0-0-main) was SKIPPED 1 time".   I don't see this warning at a 1kHz
> update rate.
>
> Are these reasonable results, and does this imply that the fastest rate I
> can
> expect without errors/warnings is 1 kHz?
>
> Would I get significantly better results using the Ethercat kernel module
> for
> my chipset?
>
>
> Thanks,
>
> Curt Fiene
> Cybermetrix
> _______________________________________________
> etherlab-users mailing list
> etherlab-users at etherlab.org
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>
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