CODESYS RTE run on Intel Atom E3940 processor (1.6 GHz) with 8GB DDR3L memory

hambergg
2020-11-18
2020-12-11
  • hambergg - 2020-11-18

    Hello CODESYS Support team,

    Our company build an IPC product with CPU spec which title mentioned.
    From RTE Toolkit instruction for Win10 installation, we adjusted BIOS setting included disabled EIST, Turbo,C state ,Hyperthread Suspend...etc.

    We found when EIST was disabled that lead to this CPU clock rate down to 800MHz, which was suffering even general operation in clean Win10.

    Don't even think the target is running ECAT on CODESYS RTE and do simple softmotion, that performance might put a question mark on it.

    Did you get any suggestion for our application?

     
  • eschwellinger

    eschwellinger - 2020-11-18

    Hi,
    your Atom E3940 processor has 4 cores, so I think should be possible to do SoftMotion even not only simple motion. Sure hard to say, depends on how mandy axis you have on EtherCAT and what exaclty they need to do.
    You need to check the JITTER and check with CPUZ if the CPU core clock is stable.

     
  • hambergg - 2020-11-19

    Thanks for the reply.
    EtherCAT bus control performance we configured 200us to test jitter, and we got 200us Β± 130us for min/max value.
    However, let's discuss the root cause from the issue, Through comparing with several CPU platform we found the ApoloLake(E3940) clock rate was decreased too much due to we closing the EIST function in BIOS.

    Please discussed with your colleague that is closing EIST function a "must" configuration?
    What would it happen if we enabled EIST function in BIOS for running CODESYS RTE in Win10?

     
  • eschwellinger

    eschwellinger - 2020-11-19

    it is not a must, from our experiance some Bios allow to enable EIST others not.
    Do not forget to delete this registry keys if you change the setting:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\CmpDrvSchedulerAMP\Params
    What is the difference in JITTER with enabled EIST?
    EtherCAT bus control performance we configured 200us
    you mean you set the task cycle to 200us??

     
  • hambergg - 2020-12-11

    Here to clarify the testing result:

    CPU - Intel Atom E3940
    Test platform - Win10 Enterprice LTSC_x86 CODESYS RTE V3.5 SP16 Patch1
    EtherCAT_Task - Cyclic 200us setuped
    Result - Aver. cycletime 45us
    Max. cycletime 134us
    jitter -1us*
    jitter Min. -60us
    jitter Max. 63us

    From our understanding the real Jitter in this case should be 63-(-60)= 123us.

    this value was higher than all cases we met before, which was usually <70us in previous cases with Win7.
    (* BTW, is "Jitter value" showup concept changed in this version?)

     

    Last edit: hambergg 2020-12-11

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