Increase performance of the Ethernet

Technical Support
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1

Hi,
I need to send and receive an Ethercat frame every millisecond.

In my customized operating system, RT patches have been enabled. I have a thread that sends a frame and the second thread that receives frames. The network is Ethercat so when I send the frame this is modified on the fly and I receive it instantly. Both threads are configured as SCHED_FIFO and RT priority. The first thread sends the frame and is suspended on semaphore. The semaphore will be freed from the second thread when the frame is received.

[First Thread]

  • get time start
  • send frame
  • wait semaphore
  • get time end
  • wait until to 1 millisecond

[Second Thread]

  • wait Ethercat frame
  • free semaphore

Normally I have a time (end time - start time) of about 600usec between sending and receiving (I can wait for 400usec), but sometimes I have 1.5msec frames. How can I avoid these 1.5 msec frames? Is there a way to increase the priority of the IRQ and / or interrupt thread? Do you have any advice?

Regards Davide

PS: I don’t have any applications with UI, but for now in my image there is LXDE. In addition to system ones, I have no other applications.

2

hi @Davide1976

Is there a reason, that you set the question to private? With private question, the community cannot provide you any feedback.

Best regards, Jaski

3

hi @Davide1976

Normally I have a time (end time - start time) of about 600usec between sending and receiving (I can wait for 400usec), but sometimes I have 1.5msec frames. How can I avoid these 1.5 msec frames? Is there a way to increase the priority of the IRQ and / or interrupt thread? Do you have any advice?

Are you sending always same amount of data? How often do you have 1.5ms frames?

PS: I don’t have any applications with UI, but for now in my image there is LXDE. In addition to system ones, I have no other applications.

If you don’t have any UI, you could switch also to the Console Image.

Best regards, Jaski

4

Jaski, you’re right I’m wrong to set it as private.

5

Yes, I always send about 1500 bytes. It can happen 1/2 times every 5 minutes. However the frequency is random.

Surely I will switch to a console image, but for the development I am comfortable to have the graphical interface.

Regards Davide

6

Hi

Thanks for this information.

I think you need to find using tracing tools like LTTng which part/process of your application is doing this delay. Further you can try to set the priority of your application to highest possible.

Best regards, Jaski

7

Ok, thank you very much. I try.
Regards Davide

8

Perfect. Let us know about your results.