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GET Gestalt/api/data/values/{dsn}?tag={tag_name_1}&tag={tag_name_2}&function={function}&start={start}&end={end}&step={step}
Performs a tag data query on a data source.
For .NET developers, we recommend that you use the IntelligentPlant.AppStore.Client NuGet package to query for data, available on the App Store NuGet feed (https://appstore.intelligentplant.com/nuget/nuget/).
For the function field supported values vary from driver to driver, but it's safe to assume that the following values will be supported:
- RAW - for raw historical data (not recommended due to the potential high volume of data returned)
- NOW - for the current snapshot value
- INTERP - for interpolated data
- PLOT - a display-friendly aggregation for when you want to display a trend on the screen
- MIN - minimum value calculated at each sample interval over a time range
- MAX - maximum value calculated at each sample interval over a time range
- AVG - mean value calculated at each sample interval over a time range.
For start and end, you can specify either an absolute value or a relative value. Absolute values should be specified in ISO 8601 format (i.e. yyyy-MM-ddTHH:mm:ss). You can also include a suffix of Z to indicate a UTC time stamp, or you can specify an offset from UTC. If no time zone information is provided, the date is assumed to be UTC. For example, if you wanted to specify 3:30:35am on 01 August 2017 in Central US time, you could specify 2017-08-01T03:30:35-06:00.
Relative values can be specified using * to represent the current time. For example: *-1d = “1 day before current time”, *-27.5m = “27.5 minutes before current time”, and so on. Possible time units when specifying a relative time stamp are: d, h, m, s, ms.
For the current value, specify NOW for the function parameter. When you use NOW, you don't need to specify a start or end time. For example, to get the current snapshot value for tags called Tag1 and Tag2, you would use:
gestalt/api/data/values/{my_dsn}?function=NOW&tag=Tag1&tag=Tag2
To get all raw data in a time period, you use the RAW function. When asking for raw data, you don't need to specify a sample interval or a point count:
gestalt/api/data/values/{my_dsn}?function=RAW&tag=Tag1&start=*-1d&end=*
RAW queries are strongly discouraged, due to the potentially large data set that must be sent over the wire.
For other functions, you need to provide either a step parameter that specifies the sample interval (e.g. 1m, 5m, 8h, 3d), or a points parameter that specified the number of samples you want to be returned:
gestalt/api/data/values/{my_dsn}?function=INTERP&tag=Tag1&tag=tag2&start=*-1d&end=*&step=1h
gestalt/api/data/values/{my_dsn}?function=PLOT&tag=Tag1&tag=tag2&start=*-1d&end=*&points=750
More info on App Store API can be found here