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Compressed Data

Synopsis​

This operator reads recorded (compressed) values of one or multiple PI data points via the PI Web API. Alternatively, a single performance equation can be evaluated.

Input​

connection​

This input port expects a Connection object if any. See the parameter connection entry for more information.

Output​

output​

This output port delivers either the recorded time series (compressed) for the specified data points or the values of the performance equation for each record of the references data items.

connection​

This output port delivers the Connection object from the input port. If the input port is not connected the port delivers nothing.

Parameters​

Connection entry​

This parameter is used to specify a repository location that represents a connection entry. The connection can also be provided using the connection input port.

Root path​

Overrides the root path (data server) specified in the connection.

Query type​

Specifies whether to look up a list of data items or to evaluate a performance equation.

Client side batching​

Enabling client-side batching splits the request into a sequence of smaller requests. Client-side batching allows to pull data sets larger than the PI Web API limit for single requests (often set to 150000 values), but adds overhead for requests below this limit.

Data item​

The tag of the data item to look up.

Additional data item​

An optional list of additional tags of data items to look up.

Join data​

Joins data points by timestamp resulting in a single time series. Joining data is only supported for data items with at most one value per timestamp. If disabled, the operator will concatenate the series for the different data items instead.

Expression​

The performance equation to be evaluated.

Result type​

The expected result type of the given performance equation.

Start time​

The start time of the period for which to read values. Supports both date times and relative intervals. The default behavior is to start one day ago ('*-1d').

End time​

The end time of the period for which to read values. Supports both date times and relative intervals. The default behavior is to read data until the moment the operator is executed ('*').

Time zone​

Specifies the time zone to use for evaluating the given start and end time.

Filter expression​

An optional filter expression. Expression variables are relative to the data point. Use '.' to reference the containing attribute.

Boundary type​

This parameter determines how the times and values of the returned end points are determined.

  • inside: Specifies to return the recorded values on the inside of the requested time range as the first and last values.
  • outside: Specifies to return the recorded values on the outside of the requested time range as the first and last values.
  • interpolated: Specifies to create an interpolated value at the end points of the requested time range if a recorded value does not exist at that time.

Max count​

The maximum number of values to be returned for each data point.