To use the STDDEV Function
STDDEV(Tag1,Tag2,...)
The Standard Deviation is a measure of how much of variation or dispersion of a set of data values. A low standard deviation indicates that the data points tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.
STDDEV(Demo-influxdb/DEMO_01TI031.PV,Demo-influxdb/DEMO_01TI032.PV)
