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

Hello,

I am facing problem of communication by connecting one AFDis to 2 DP/PA Coupler Ex [i] (redundant ring configuration). The T1, T2 LEDs on AFDis remains ORANGE and S1 (one instrument connected) remains OFF. Also the PA LED on the couplers remain OFF. These denotes PA communication is not through between the Couplers and the AFDis as well as the instrument is not getting power.

But connecting the AFDis to FDC157-0 everything becomes fine - T1, T2 LEDs on AFDis goes GREEN, S1 becomes BLUE, PA LEDs on the FDC157-0s start flashing YELLOW. But this is not intended configuration. AFDis is to be used with DP/PA Coupler Ex[i] - not with FDC157-0.

It is mentioned in the ProfiBus PA link device manual (dppa_coupler_afdis_dppa_link_y_link_manual_en-US_en-US.pdf) that the DP/PA Coupler Ex[i] (6ES7157-0AD82-0XA0) can generate 13-14VDC at the output to be put to the PA bus for supply to downstream AFD, AFDis, instruments.

But for the AFDis (6ES7157-0AG83-0XA0) it is mentioned that the minimum permissible input supply voltage from the bus is 16VDC.

As we know that DP/PA coupler Ex[i] has to be used for intrinsically safe zone areas with instruments connected via AFDis, how can 13VDC output supply of DP/PA coupler Ex[i] can feed power to minimum 16VDC input supply AFDis?

I have attached the datasheet of the 2 devices extracted from the manual for ready reference.

regards,

rajudon

New question published by KVOJ is split to a separate thread with the subject DP/PA couple, signal from the PA device intermittent.

Best regards
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