Constructing I/O List for 1st time

[esung911]

Good morning,
Please forgive me if my questions sound newbish but my team has just started making the transition from traditional hardwired I/O to FF thanks to training from various vendors. We've taken our traditional I/O database and tuned to include fields for FF.

Now that we are getting diagnostic data from each FF instrument, how do do our I/O count estimates?

Does each diagnostic point require an I/O point in our I/O database such that:
PT100 - Raw reading
PT100A - Diagnostic A
PT100B - Diagnostic B
PT100C - Diagnostic C

My team is having a debate about this because this could potentially increase our overall I/O exponentially. I would think that when we do customization of the diagnostic info, it would be defined seperately for the Asset Management system rather than DCS I/O. How should we populate our I/O database?

[jberge]

In most cases the number of licensed tags are counted as the number of function blocks used. Since value, status, and diagnostics are all parameters within the same block it is just one tag. Therefore the number of licensed tags will not increase dramatically. However, for multiple point IO function blocks representing e.g. 8 measurement points these may be counted as 8 licensed tags - as if you had used 8 individual transmitters.