Why is the signal from the PA device intermittent? What should we do to correct this problem?

See attached PDF for the setup.

Hope to hear from you asap.

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Split from ProfiBus PA DP/PA Coupler Ex[i] and AFDis supply voltage.

Hello,

maybe for first look/attach diagnostic buffer, we can look to it.

Hi Sir,

Thanks for the reply.

Attached is the screenshot of diagnostic buffer.

I really need an answer. Our project was delayed because of this issue. 

Hope you will help me.Thanks experts!

Regards

Hello KVOJ,

Check all the Profibus DP and PA wiring. (e.g. connectors, terminators, recommended distances from power cables)

Once you verified all the physic layer is OK. I recommend make a Profibus Diagnosis with a Profibus analyzer (e.g. procentec, softing). Then you will realize if the problem is in the physical layer or is a configuration problem. But if you are loosing communication my guess is a physical layer issue.

Regards,

Alvaro

Hello KVOJ;

In the following Word page I have extracted from the DP/PA coupler manul 2 elements that might be part of the problem.

The most important one is the Profibus-DP bus speed: if you are using a DP/PA coupler (FDC 157) as a stand-alone unit, you do not need to configure it on the bus (only the PA instrument using its GSD file); however the bus speed of the DP must be brought down to 45,45 kBaud. What are your present settings (right-click on the Profibus line of the HWConfiguration editor, and open the Bus Parameters tab)?

In any case I suggest you review chapter 7 of the manual (the link is attached to the document), it describes the basics of commissioning a DP/PA coupler. You should find a good number of hints for your application.

Hope this helps,

Daniel Chartier