Polybench® Reference
Using variable parameters, this operator allows to read or write information to or from measurement sessions.

Measurement Information


Use this information operator (that does not connect to any other operator) to read or edit information items of a measurement session, as well as to control the creation of measurement sessions, or to reopen them or to close them explicitly. You can also use this operator to get a unique alias for the current session.

The information you can edit is displayed in the Data Manager in the measurements list and information panel below that list.

A measurement session may contain multiple measurement files, and contains a record of what has been measured. More details about a measurement session record can be found here: "Measurement Session Record".

Operator ports

This operator does not have inputs nor outputs. It cannot be connected to anything. You are free to place it anywhere on a design page.


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

type: Word or phrase
The name of the object in the project. This name must not contain '.', '$' nor '@' characters.

For more information about the rules and usage of the Caption property, please refer to "Caption property - background and usage".

type: See description
Optional documentation of this object. If this object is an operator, the Documentation text is displayed below the operator symbol.

Variable Parameters

Find more information about Variable Parameters here: "Variable Parameters"

type: Parameter list (see "Parameter List")
A list that contains all measurement information of the currently selected or running measurement session.

The items that are not grayed out can be changed from within your application. Changes are immediately reflected in the Data Manager.
For an overview of items that are shown in the list, please refer to the Measurement Session Record ("Measurement Session Record").

type: Parameter list (see "Parameter List")
A list that contains all aliases of files in the currently selected or running measurement session.

type: Parameter list (see "Parameter List")
A list that contains the file captions (titles) of all files in the currently selected or running measurement session.

type: See description
If this parameter contains a word, then this word is a file alias that is not yet used. If you copy an alias name to this parameter, then it may be changed so that it is unique for the current measurement session.

For more information about stream aliases, please refer to "Stream Alias - concept for naming of data files".
A measurement session may contain multiple files. Every file of the measurement gets an 'alias', which is a short reference name (read more here: "Stream Alias - concept for naming of data files").
Within one measurement, each alias must be unique. Now, if you want to store a new file in an existing measurement, then you have to specify a unique alias for that file. The UniqueAlias parameter helps with getting a unique alias. Just write an alias to it and read it back to get a guaranteed unique alias.


Find more information about Functions here: "Operator Functions"

Starts a measurement session, if no session has already been started by another storage component.
Optionally specify the name of the folder of the measurement session. You may use variables to construct the folder name. You cannot use back-slashes ('\') in the name!. If you do not specify anything, then the Data Manager determines what the session folder name will be, which is described in the Format of the folder name for a new measurement option of the Data Manager ("Options").

Ends a measurement session, if that is allowed and if there are no storage operators that are currently storing data. If all storages have stopped, the Data Manager will still be locked (it still expects new data). By calling this function, the session is closed and the Data Manager will unlock.

Reopens the currently selected measurement session, if no session has already been started by another storage component. This function allows you to add files to an existing session. If there are no sessions to reopen, then a new session is started as if the StartSession function was called.
Optionally specify the session folder name, in case no session could be reopened, and a new session is opened instead. For more info see the function StartSession.

Immediately updates the current session information, that can be read in the variable parameters of this operator. The information will otherwise be updated at regular intervals, but using this function you can make sure that you have the most update information.


Edit session information during or immediately after recording a new measurement

If an application contains Storage operators to store recording files and also contains a Measurement Information operator, then the information items you can find in the variable parameters can be edited online. Any change is added to the open session record.

For example, if an Input Field ("Input Field") would be linked to one of the editable items in the variables parameters, and the user of the application enters some text, then this information is immediately added to the record.

Also, if the measurement has been stopped, but the application is still active, then this meta-data of the measurement that has just been recorded can still be edited.

If you need to fill out measurement meta-data before data is being stored, then you will need to deliberately start a measurement session, using the function StartSession.

The current measurement session closes when the application is closed, or when a complete new measurement has begun in the same application. If no storage is going on anymore, then you may deliberately end a session by calling the EndSession function. Please mind that you do not have access to the data that were just recorded after you have ended the session.

Edit session information for a previously recorded measurement

If you select a previously record measurement in the Data Manager, and then start a post-process application with a Measurement Information operator in it, then the meta-data of the measurement session are available for editing in that application.

Every change that is applied to any of the meta-data fields is immediately reflected in the Data Manager.

Reopening a measurement session to add recording files

It is possible to add more data files to a measurement session after a session was closed. To do this, select the measurement you intend to change in the Data Manager, and then in your application call ReopenSession.
Now using a Storage operator ("Storage"), or for example using the Image Writer extension ("Image Storage Extension") you can add files, as long as the aliases of the new files are always unique within the measurement session.

Specify the folder name of a measurement session

Using the StartSession and ReopenSession functions you can specify the path name of the measurement session, by writing the name in the argument of the function call.

For each new session, a folder is created in the folder of the current patient. If no folder name is specified, then a default folder name is created by the Data Manager, which is based on settings of the Data Manager (see Options "Options").

It is not possible to specify subfolders within the patient folder, so each measurement session is one folder deep relative to the patient root folder. However, this folder name can be specified using variables.

So a measurement folder name could be:

$year$$month$$day$ Awake

whereas the next measurement folder name could be:

$year$$month$$day$ Sleeping

In this example, the folder structure on disk could look like this:

To set these folder names, you would call a FUNCTION action ("FUNCTION"), where the address is the StartSession function of this operator, and the value is for example '$year$$month$$day$ Awake'.

Note that you have to take care that each measurement session gets a unique folder name, otherwise measurements may get mixed up (unless you intend to do this).


Example: Session name demo
Demonstrates how to give a measurement session any name. If the session is not explicitly renamed (like in this demo), it will get the name of the application (if that name is specified).
In this demo, when pressing Stop, in the action sequence the current session is renamed, and given a name that contains information provided by the Storage operator. Then, the session is explicitly closed.