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CRIO-PN (Profinet IO) doesn't support ISOCHRONOUS Mode in TIAPortal?

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Dear All, 


I have just bought a CRIO-PN Module to be used on the NI CompactRIO, The reason why I want buy it is to relize IRT high speed control, the IRT mode is said to be supported on the CRIO-PN documents.


The reason why I want have this function is that, I need relize accurate Motor position control in the Isochronous Mode (at least 5ms, evenly), but after I do the test, the result is kind of frustrated, as there is no Isochrnous Mode can be checked for this Module in the TIAPortal as picture below, the normal one should like the picture on right, which Isochronous mode can be checked, but in the CRIO-PN one, there is no this check .














I want know if there is Isochronous Mode can be used for this CRIO-PN Module? After I run the test with no Isochronous mode checked, the result is not good, I send the command by Labview Real-time, 5ms, but the command received is varied from 5ms to 15ms, which as picture showed below left side, which cannot satisfy my demand for the accurate Motor Position Control. I think this CRIO-PN is used for the CompactRIO Real-time function, this result really frustates me, and I want reach the result as right side, which is all evenly 5ms.








I want know if there is any method to solve this problem? Or, If there is any latest GSDML file which supports this function? As whether this mode can be checked or not depends on the description in the GSDML in my way of thinking, Or, If I can modify the GSDML file to have this function on?  I am really desperate for this help. as profinet is the basis control of the whole system, if the Profinet control cannot meet the specificaiton, there is no need to buy CompactRIO and CRIO-PN module anymore. I really hope NI and Kunbus can help me to solve this, thank you very much in advance.

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Sorry, After I modify the GSDML file, I add the isochronous mode in the TIAPortal,

And I found out that the not equal time problem is due to my software bug

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Accepted by topic author chenzixin
12-12-2018 06:30 PM


Please note that the cRIO PN module do not support IRT Services on application level. The cRIO PN documents you mentioned refers to the physical layer of the PROFINET interface. This means that the module can be used within a PROFINET network without interrupting IRT communication.


Best regards

Michael Flattich
Team Leader Product Development


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