Why does the PCD7.F7500 does not work on the PCD2.M5540?

FAQ #101655

Symptom
The Profibus Master module PCD7.F7500 does not work while commissioning. During start-up of the PCD the Error LED is lit and in the history the message "PROF DP FAIL 000" is added (see screenshot from a diagnostic file below):

Reason
In some specific cases the PCD2.M5540 does not detect the PCD7.F7500. As result, the module can not be configured and the Error LED of the PCD is lit.
The PCD2.M5540 hardware version C with modification 3,5,6 contains a modification of the CPLD which assures that the module PCD7.F7500 it detected correctly.

Solution
Please use the PCD7.F7500 module with a PCD2.M5540 with the hardware version/modification "C 3,5,6"or newer.

In case you are concerned by this case and your PCD has an older version (e.g. version/modifications "C 3,4,5"), you need to replace the PCD2.M5540 with a newer one.

Remarks

• If the PCD2.M5540 is running with a PCD7.F7500 there is no need updating the hardware, even if the modification above is not applied (because the problem does only occur on some combinations of CPU and F-module
• Since May 2011 the PCD2.M5540 delivered by Saia-Burgess Controls AG have the modification 6 or later applied.