FirstRawValue/FirstRawTime Modes

Retrieves the first good raw sample value or timestamp for a given time interval.

Value
The value of the raw sample or zero if there are no good raw samples in the interval. The timestamp of the sample or the year 1969 if there are no good raw samples in the interval.
Quality
The quality is the same for FirstRawValue and First RawTime. If there are no good raw samples in the interval, then the percent good is 0. Otherwise, the percent good is always 100, even if the interval contains bad quality samples.

The Raw sample has a quality of Good, Bad or Uncertain, and that is converted to a 0 or 100 percent.

Example: Retrieving the FirstRawValue/FirstRawTime Values

Import this data to Historian: 

[Tags]
Tagname,DataType,HiEngineeringUnits,LoEngineeringUnits
Tag1,SingleFloat,60,0
[Data]
Tagname,TimeStamp,Value,DataQuality
Tag1,07-05-2011 17:24:00,29.72,Bad
Tag1,07-05-2011 17:25:00,29.6,Good
Tag1,07-05-2011 17:26:00,29.55,Good 
Tag1,07-05-2011 17:27:00,29.49,Bad
Tag1,07-05-2011 17:28:00,29.53,Bad
Tag1,07-05-2011 17:29:00,29.58,Good
Tag1,07-05-2011 17:30:00,29.61,Bad
Tag1,07-05-2011 17:31:00,29.63,Bad
Tag1,07-05-2011 18:19:00,30,Good
Tag1,07-05-2011 18:20:00,29.96,Good
Tag1,07-05-2011 18:21:00,29.89,Good
Tag1,07-05-2011 18:22:00,29.84,Good
Tag1,07-05-2011 18:23:00,29.81,Bad
Using FirstRawValue Calculation Mode
set starttime='07-05-2011 16:00:00', endtime='07-05-2011 19:00:00'
select timestamp,value,quality from ihrawdata where tagname like 'Tag1' and samplingMode=Calculated and 
CalculationMode=FirstRawValue and intervalmilliseconds=1h

The output is as follows:

Time StampValueQuality
07-05-201117:00:000.00000000.0000000
07-05-201118:00:0029.6000000100.0000000
07-05-201119:00:0030.0100.0000000

For the time interval 16:00 to 17:00 there are no raw values so a value and quality of 0 is returned for both FirstRawValue and FirstRawTime. The first raw sample from17:00 to 18:00 is 29.72 but it is a bad data quality so it is skipped and the 29.6 is returned and its timestamp of 17:25 is returned in FirstRawTime. FirstRawValue calculation mode considers only good quality data. In the last interval the first good raw sample is 30 and is returned and its timestamp is returned as FirstRawTime.