Polybench® Reference
Device or file information record that stores user and technical information about the device or file.

Device or File Information Record

Overview

The Device or File Information Record is a record with technical and user information about a measurement device (front-end) or a signal data file.

Properties

Find more information about changing properties here: "Properties Viewer"

Path
type: See description
The path that points to a data stream (from a file, a device, etc.)

If this record describes a file on disk, then the Path is the file name of the file, for example C:\Measurements\RecordingFile.csv.

If this record describes a device, then the Path is some kind of connection string or device identifier, which depends on the device driver - or Path is empty.

Stream Alias
type: See description
The short name of one type of data file, so that it is possible to refer to the same kind of file for multiple measurements. For example: ECG.

For more information about stream aliases, please refer to "Stream Alias - concept for naming of data files".
The stream alias should be short and must not contain spaces or other special symbols (letters and numbers only).

Caption
type: Word or phrase
The caption, title or name of the device or the file.


Data Source Type
type: Undefined [this value cannot be changed]
Device or file type (what kind of device/file it is), and version information.

If this record describes a file, then the name of this type specifier is the extension of the file, for example 'csv' for files with the .CSV ending.

Source application info
type: Undefined [this value cannot be changed]
Optional Information about the application and the platform that has created this data stream.


Reference Identifier
type: See description
User defined reference to other data (e.g. a patient name or number).

This item is used to inform the user about other data sources that have a relation to this record. In practice, this will be some reference code to other files, a patient name or an experiment name.

Measurement Information
type: See description
Optional user defined information of recording location or recording setup (could also be a person's name to identify the one that performed the measurement).


Source Information
type: See description [this value cannot be changed]
Optional information about the source of the data stream, such as exactly which recording device was used.


Software Information
type: See description [this value cannot be changed]
Optional information about the software that was used to control the device or that was used to create or change the data file.


User Notes
type: See description
Optional user notes to the device or file.


Foot Print
type: See description [this value cannot be changed]
The foot print of a device or file is a list of units per channel. Every unit is enclosed by quotation marks, and the list is comma-separated. Some channels may not have a unit, in which case empty quotation marks are used.

The foot print is technical information to specify or identify a data stream. The software uses this information to find similar files or devices, if it does not have other information to exactly determine data streams.

First Sample Number
type: Integer value [this value cannot be changed]
The first sample number of the data stream. This is only relevant to signal data files, otherwise the value is -1.

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Total Count of Samples
type: Integer value [this value cannot be changed]
The total number of samples of the data stream, or -1 if the total length is not (yet) known, or if the value is irrelevant.

You can calculate the duration of the stream in seconds by dividing this value by the sample frequency.

If this record describes a device, then the total number of samples is irrelevant in most cases.

Count of Samples per Block
type: Integer value [this value cannot be changed]
If the data stream is divided in blocks of data, this is the number of samples in one block. Most files and devices make working sets of multiple samples for efficiency reasons.


Start Date and Time
type: Undefined [this value cannot be changed]
The time and date a file was created, or when a device was first started.

Details

Note that the same information structure is used for devices and files, although both may use the record differently. For example, the Path item for a file has a different meaning than for a device.