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OASyS PI Interface instance

Interfaces are software modules for collecting data from a computing device with measure such as AVEVA Enterprise SCADA. There can be more than one interface running at one time. This field indicates the interface instance number (interface ID number) in case multiple PI-OASyS interfaces are running concurrently.

Collection type

This field indicates the collect methods that the PI-OASyS interface uses to retrieve data from the AVEVA Enterprise SCADA data source.

Command timeout period (sec)

This field is not supported.

Scan class (defines collect period)

This field determines how often to poll for new values.

Telemetry Point

The point field whose data is being measured and collected.

Engineering Units

The engineering unit string describes the units of the measurement. Any string of any length may be used, however the PI API only retrieves the first 12 characters. Examples are: Degrees Centigrade or gallons per minute.

Instrument tag

This field is not supported.

Source tag (output trigger)

This field is not supported.

Data type (Pointtypex)

The list of data types for a PI point that are supported by the PI- OASyS interface. The data type of a PI point does not need to be the exactly same as its device point type. For example, integer values from a device can be sent to floating point or digital PI tags. Similarly, a floating-point value from the device can be sent to integer of digital PI tags, although the values will be truncated. In almost all cases, a RealTime database (RTDB) status point should be configured as a digital tag, and data quality tags should be digital tags. The complete list of types is:

• Digital

• Float16

• Float32

• Float64

• Int16

• Int32

• String

Digital set

A collection of digital states is called a digital set. For example, a digital state can consist of two states: Open and Closed. This field is only active when the Data Type (Pointtypex) field is set to digital. Refer to Select a digital set.

Span

Specifies the difference between the top and bottom range. Span is required for all numeric data types.

Zero

A zero is required for all numeric data types to indicate the lowest value possible. It does not have to be the same as the instrument zero, but is usually the logical choice. Certain interfaces require that the zero and Span match the instrument system range. The zero is the bottom of the range used for scaling float 15 values for the PI archive.

Typical Value

The typical value is used only to document an example of a reasonable value for the point. For a numeric tag, it must be greater than or equal to the Zero, and less than or equal to the Zero plus the Span.

Number of digits to display

This field controls the format of numeric values on screens and in reports. Zero or a positive number indicates the number of digits to display to the right of the decimal point. A negative number indicates the number of significant digits to display. In this case, the absolute value of this field is the number of significant digits.