I have a development VM with a PI stack, that i suspend and awaken daily for my development work. Within that VM i have a few analytics to generate test data. Run on a periodic trigger, that works will to generate 10 years of historical data using the analytics backfilling.
The analysis increments the current value with a random number, and when there is no current value, the value is initialized using that random number:
IF (BadVal('attribute')) THEN (Rand()) ELSE ('attribute' + Rand(('RandomSeed'/2),'RandomSeed'))
But every time i awaken, some of the attribute values will get reset to the random value. I assume this is due to the BadVal, and not being able to read the data from the PI tag on pulling back my VM from suspend.
Any ideas how to overcome this? And how to make the distinction between not having a connection at all, or just not having values for a specific attribute?