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Hi Andreas<br>
<br>
Yep 4K is no problem is higher that is a problem. We have 2 bus
couplers in a daisy chain on my test rig, and 4 IO modules.<br>
<br>
I'll try a different card soon, but I've used both the generic and
non generic Intel drivers with no different in the possible rates.<br>
<br>
4K works great doubling it to 8K the SKIPPED goes though the roof,
as I said I've confirmed the bus coupler is not an issue the issue
is the PC not doing the right thing with the packets.<br>
<br>
I just really want to now what sort of rate could be achievable with
etherlab. The packet captures I've seen seem to indicate that the
bus couplers are able to run a very high rate. (ie at least 25K)<br>
<br>
Mike<br>
<br>
<br>
On 21/03/12 11:13 PM, Andreas Stewering-Bone wrote:
<blockquote class=" cite" id="mid_4F69CCF1_5090800_igh_essen_com"
cite="mid:4F69CCF1.5090800@igh-essen.com" type="cite">Hello Mike,
<br>
<br>
The max rate depends on your bus topology (Number of Slaves,
Number of EKXXX modules).
<br>
Generally 4K should be no problem.
<br>
<br>
But if you have the possibility, please do not use Intel cards,
try a stupid Realtek card.
<br>
Intel cards are known to have some freatures which can make some
trouble at higher rate.
<br>
<br>
Do not use the generic interface for such rates, please use the
native drivers.
<br>
<br>
Greatings
<br>
<br>
Andreas
<br>
<br>
Am 21.03.2012 13:25, schrieb Mike O'Connor:
<br>
<blockquote class=" cite" id="Cite_0" type="cite">Hi All
<br>
<br>
I have been testing with Etherlab and a small number of Beckhoff
Digital
<br>
IO, the Ethercat (not Etherlab) technical data seems to indicate
that an
<br>
updates at a rate of at least 30 micro seconds for up to 1000 IO
points
<br>
(possibly faster for smaller numbers) is possible.
<br>
<br>
I adjusted the user land examples to work with our IO and then
started
<br>
increasing the frequency and found that at 4K I get no issue
(maybe a
<br>
couple of the dmesg messages below at the start)
<br>
<br>
[ 412.872048] EtherCAT WARNING: Datagram f6bbfc00 (domain0-0)
was
<br>
SKIPPED 6 times.
<br>
<br>
but as I increase the rate to 8K then 12K and finally 25K the
number of
<br>
SKIPPED gets larger and larger
<br>
<br>
[173178.785515] EtherCAT WARNING: Datagram f6851360 (domain0-0)
was
<br>
SKIPPED 43476 times.
<br>
<br>
I did adjust the intel GigE driver (e1000e) to use a
<br>
InterruptThrottleRate of 0 which helped a lot with consistency.
I also
<br>
tried the non generic drive with no change in the above
messages.
<br>
<br>
I've confirmed via a mirror port on a switch and a capture of
the
<br>
packets that the IO is replying to every packet we send and that
the
<br>
rate of sending would seem to match the 8K, 12K, and 25K.
<br>
<br>
This seems to indicate to me that the issue is in the Ethercat
master,
<br>
is etherlab up to the task of running a high scan rate ?
<br>
<br>
Thanks
<br>
Mike
<br>
<br>
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<br>
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<br>
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<br>
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<br>
</blockquote>
<br>
<br>
Mit freundlichem Gruß
<br>
<br>
Andreas Stewering-Bone
<br>
<br>
</blockquote>
<br>
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