Profibus DP Link

Hi, I’m trying to install a new point to point profibus link between deltav and a red lion HMI.

From an S-series DeltaV Profibus DP Card, were connected to a STAHL 9186/25-12-11 Fibre Optic fieldbus isolator repeater using profibus cable, then using a fibre cable connected to another STAHL 9186/25-12-11 Fibre Optic fieldbus isolator repeater then to the Red Lion HMI.

When all the components were first powered up during the FAT, the link worked and data was coming across from the HMI to DeltaV. We powered cycled the HMI to simulate a loss of field device to see how deltav responded, displayed the process data. On restoring power, we weren’t able to get the profibus link back operational.

I’ve done some diagnostics and suspect the STAHL 9186/25-12-11 Fibre Optic fieldbus isolator repeater is at fault.

With the STAHL 9186/25-12-11 Fibre Optic fieldbus isolator repeater connected to the DeltaV profibus card, the profibus card RED LED flashes. As soon as the profibus cable is removed from the STAHL 9186/25-12-11 Fibre Optic fieldbus isolator repeater, the RED LED goes out. It appears as DeltaV doesn’t like the STAHL 9186/25-12-11 Fibre Optic fieldbus isolator repeater.

I installed a different type of repeater, a STAHL 9186/12-11-11 Fibre Optic fieldbus isolator repeater to both ends and strangely, the DeltaV profibus card was still healthy, although the transmit and receive LEDs were active on the repeaters, and the profibus card port LED was steady, no process data was coming via the profibus link.

We have a different model of repeater of different profibus networks which are working fine, these are STAHL 9186/15-12-11 Fibre Optic fieldbus isolator repeater.

Does anyone know why the deltav profibus card wouldn’t like the STAHL 9186/25-12-11 repeater? Or maybe why no process data was coming across when using the STAHL 9186/12-11-11 but the repeaters were transmitter and receiving data?

1 Reply

  • Flashing RED LED is documented to indicate either Controller not scanning the card, or an address conflict on the segment or the Profibus card should be replaced. If you can confirm the DP card works with some devices, the issue is clearly the repeater.

    Have you looked in DeltaV Diagnostics to see if there is more information behind the blinking LED? This may confirm one of the possible sources.

    Is the port yellow LED on solid (good) flashing (comm error) or Off, no communications? Again, check diagnostics.

    Do you have any other Profibus devices connected to the segment on the DeltaV master side? Can you see them through diagnostics.

    Andre Dicaire