Lots of diagnostic data is available from fieldbus devices, and we at the Fieldbus Foundation have put a lot of effort into making it easier for end users to prioritize diagnostic information and manage it effectively. Everything from incorporating NAMUR NE 107 recommendations into our specification and other aspects of our FF 912 diagnostics specification is done with eye toward turning diagnostic data into useful information. You also have to consider the impact of standards such as the ISA18.2 standard for alarm management. A true alarm, according to ISA18, is one that requires immediate operator intervention. You don't want to confuse your device alerts and diagnostic messages with true alarms. There is a great post from Jonas Berge on the Emerson Process Experts web site that discusses this issue, along with some more information on how utilize fieldbus diagnostic data effectively.
Emerson Process Experts: Intelligent Field Device Diagnostic Alarm Management