This suggestion is on how you manage the input tags into calculation that at some point it returned bad value (like I/O Timeout, Bad Input, Snapfix, etc...) or became questionable. These tags will make your calc at analysis become "Calc Failed". I know that we can use Exit() or NoOutput() function but it's impractical to do this again and again in each statement.
Generally "Calc Failed" can be caused by 2 reason, either the tag is bad or the calc itself cause error. But at least on the PI tags error we can handle at attributes level, and would be helpful in managing the inputs prior gets processed the calculation analysis.
As when the user tick the option to handle bad PI tag, he has few decision as suggested below:
a) Tag to remains at last good value
b) Tag to go to a specific value (like defaulted to 0 or 100 when its bad or questionable)
This decision probably will make the output analysis calc misleading but, by ticking it, the PIAF programmer must take the responsibility of his calc by choosing this option.
