[etherlab-users] How can I reduce latency of cyclic task with etherlab master?

[Andreas Stewering-Bone]

Hello,

first, the use of etherlab should not touch your system latency,

Which processor do you use?

How do you measure the latency? RTAI-Testsuite?

What are your etherlab task cyclic time?

What execution time does your software have?

On older system with high hd load you can switch of dma.

Best regards

Andreas

Am 21.10.2011 06:48, schrieb Donggu Kang:
> Hi,
>
> I'm newbe in ethercat and real-time world.
>
> I installed etherlab master(1.5-stable) with xenomai environment on my
> linux box.
> And I tried to latency test of real-time task with etherlab master API.
> I also did it without a ehterlab master API.
> A stress is "while true;do ls -lR />  /tmp/list; done&  >  /dev/null"
> shell script;
> It's called repeatedly by bash shell script and making hard disk load.
>
> When I use etherlab API, the latest latency of cyclic task is above a 500us.
> But when I don't use etherlab API, latency is about "70us".
>
> According test result, etherlab API or EtherCAT-capable network device
> is interrupted by hard disk access on my system.
> I think hard disk access is making a huge latency.
> And other devices also also become a source of latency on my system.
>
> If anyone has any advice could you please leave your comment?
>
>
> Best regards.
>
> Donggu Kang.
> _______________________________________________
> etherlab-users mailing list
> etherlab-users at etherlab.org
> http://lists.etherlab.org/mailman/listinfo/etherlab-users
>    


Mit freundlichem Gruß

Andreas Stewering-Bone

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