Freelance AC800F Profibus Diagnostic
clearly you get an extended diagnostic alarm for that CI 840. As long as you haven't found out what it means, you cannot really say it is no fault.
Have a look at the Unit and Module Tab in the diagnostic window. You can also have a look at the alarm page in DigiVis.
Once you found the reason and removed it, the diagnostics should disappear.
For sure if there is red triangular mark then need to worry and there might be configuration error/parameter fault and several other possibilities.
But in your case from image it seems like there no red triangular mark, but Blue triangular mark means diagnostic data present either standard diagnostics\unit diagnostics\module diagnostics. And that is for three slaves out of five slaves on profibus network. So good part is whichever slave(@bus address 2 & 5) is clean, no diagnostic present, you can compare with it and troubleshoot for those slaves having diag data present.
In general make channels and modules are configured accordingly,
take care that unused/not connected channels should be deactivated,
If not required then power supervision can be OFF,
And make sure proper voltage or current range selected.
If all that configuration is ok, all set and fine, Then check in standard\unit\module diag to get some sign for getting cause of diagnostics.
In your case from attached image check External diag. and watchdog setting the flag is true there in standard diagnostic tab.
Can't get you on last two questions in question descreption text...
Hope that helps…