Learn about data points

Data points contain calculated performance data. Data points support the following data types: Float16, Float32, Float64, Int16, Int32 and Digital.

To map a data point to a performance counter, enter the performance counter path in the PI point’s Extended Descriptor attribute, using the format described below in the section titled Specifying the Performance Counter Path. For more information about counters and supported formats, see the Specifying a Counter Path topic in the Microsoft Developers Network (MSDN) library. If you omit the name of the target computer, the default is localhost.

Each scan class can contain only one data point for a particular performance counter. The interface rejects any duplicate data points (data points that contain the same performance counter path for the same scan class) and logs an error.

If the interface cannot update a data point, it writes one of the following system digital states to the point to indicate the nature of the problem:

• Configure: The interface cannot initialize the point.

• I/O Timeout: The interface is not able to collect performance data from the computer, most likely because the computer is offline.

• Bad Input: The interface is not able to process raw performance data returned from a device for this performance counter, most likely because the data does not conform to the Microsoft specification (see Providing Counter Data in the Microsoft Developers Network library). One typical cause of such problems is when the value of a delta counter is smaller than its preceding value.

  Set the attributes of data points as follows:

  Tag Attribute	Setting
  Location1	Interface ID
  Location2	0
  Location4	Scan class (1 or greater)
  PointType	Numeric or Digital
  DigitalSet	None or user defined
  ExDesc (Extended Descriptor)	Performance counter path
  Span	100
  Step	0
  Zero	0
  TypicalValue	0