User Manual

LdP_Datalogger_Viewer is a tool designed to visualize time series, especially those related to internal signals of systems. It is specialized in handling data in the format generated by ACMSL Simulators (LdP framework).

It also implements a procedure for grouping the presentation of signals using criteria that help to find the temporal relationships between them: state changes, delays, responses, correlations and cause -> effect sequences.

It also generates data formats compatible with other analysis tools for this data, such as CSV files (spreadsheets).

With this manual the technical user will become familiar with concepts of:

• datalogger and signal recording,
• time series,
• different treatment of analog and digital signals,
• specialized data files, such as SQLite databases and CSV files compatible with spreadsheets,
• and graphical representation of data.

The goal is for the user to be able to:

• track the temporal evolution of relevant variables,
• compare signals in the same time window,
• locate events and transitions,
• better understand the overall behavior of the analyzed system.

1. Program Usage

To use this program, follow these steps:

1. select a data file. There are three types:,
   1. SQLite files with LdP original structure, from simulation sessions
   2. files in unified format,
   3. files in CSV format
2. select a group of signals contained in the chosen file, and a visualization structure,
3. visualize it.

The following figure shows a typical example:

1. Press Open.

2. Choose the session file of a simulator. For example: C:\WFS_Datalog\Doubly Fed Induction Generator Wind Turbine\25-11-21-09-29-36.sqlite. (This file corresponds to the session carried out with the "Doubly Fed Induction Generator" Simulator, which started on 2025/11/21 09:29:36).

3. Select, for example, the Visualization Profile Cutin + Cutout + Production. This Profile corresponds to the visualization of the Panel of the same name in the Wind Turbine Simulator Doubly Fed Induction Generator.

   NOTE: If the selector is not filled with the available Profiles, continue to the section Import .conf or Create a new profile.

4. Press Visualize.

When a Profile is selected using the selector, it is necessary to press the Visualize button for it to appear in the central panel.

From that point on, you can choose an area of interest by performing a Zoom with the right mouse button: mark the start of the zoom with the right button, and drag the mouse with the right button held down until you reach the end of the desired area. See next image.

When you release the right button, the chosen area will appear filling the entire screen. See next image.

2.1 Visualization Profile

The user can decide which signals to visualize from those contained in the chosen data file, and how they are presented in the different recorders.

This means that the user can:

• choose a reduced set of signals for a specific search,
• group in the same recorder only the signals whose visual comparison is useful,
• separate different functional blocks into different recorders,
• build alternative profiles for the same file, according to the type of analysis to be performed.

By choosing a specific Profile, we choose two concepts:

• The set of signals to visualize

• The details of the representation of those signals

The Visualization Profiles section (in the left panel) presents the available functions for selecting, creating, editing and saving the files corresponding to the Profiles for a log file, or a set of them. In the section Visualization Profile you will find a detailed explanation of these functions.

2.2 Recorders

In this initial view, after "Open -> Select Visualization Profile -> Visualize" the most important graphical elements of the application can be distinguished.

The central element is the Recorder, i.e., the canvas on which the temporal evolutions of the chosen signals are graphically represented. Each recorder occupies a horizontal strip in the visualization area and shares the same temporal reference (X axis) with the others.

2.3 Panels

Next to each recorder, on the right, a lateral information Panel appears where we find:

1. the name of the recorder

2. how analog signals are presented in this Recorder:

   • maintaining the value between one record and the next (Step)

   • joining two consecutive records.

3. the way the Y axis scale is calculated: automatic, or not. In case of automatic calculation this affects:

   • the maximum and minimum values of the recorder
   • the number and value of the horizontal reference lines. These lines are calculated automatically, based on the maximum and minimum values of all signals in the recorder, to show the greatest resolution (Auto scale).

4. details of the represented signals,

   • the color associated in the recorder
   • its short name
     
   • its value corresponding to the instant associated with the cursor.

2.4 Cursors and time interval measurement

In the upper left part, the data corresponding to the cursor instants are presented.

• "Cursor" : position of the (red vertical line), in day/month/year hour:minutes:seconds format (and milliseconds depending on the zoom level)

• "Date LdP" : position of the red vertical line, in LdP format (field "Date" in the records)

• "Ref": reference date (if it has been defined using Ctrl + left mouse button). (yellow line).

• "Delta t": distance in seconds between the red vertical line and the yellow one (reference instant).

Sometimes it is useful to freeze the cursor to be able to use the mouse for other functions. We call this the Frozen cursor. It is indicated by the background of the "Cursor" text (see next figure) turning light blue.

To enter or exit this mode, press the f (or F) key. You must have previously pressed the right mouse button at least once.

2.5 Adaptive labelling of the time axis

It is done in the first recorder and automatically adjusts to the zoom level. Examples:

2.6 Changing the visualization interval

The time interval being visualized can be controlled with:

• the All button, which presents the full temporal expansion of the dataset; (above, between "Visualize" and the language selector).

• the mouse; press the right button on the desired start instant, drag the mouse with the right button held down to the other instant, and release the right button;

• using the < and > keys, while holding down the left mouse button, a shift to the left or right of the visualized time interval of 20% of the visualized interval is produced

• using the PageUp or PageDown keys while holding down the Ctrl key, the zoom is multiplied or divided by two relative to the current one, centering the new area on the mouse position.

3.1 Selecting a Profile

In the first position of the menu we have a selector that allows us to choose among the available Visualization Profiles. The definition of a Profile is saved in JSON files.

3.2 Where are the available Profile files located?

Since Visualization Profiles reference a set of signals, these signals are implicit in the data files. Since there may be data files that share signals (for example, the files from LdP simulators), this application expects to find the Profile files grouped together with the data files. For example, for data coming from sessions with the "Rotor Resistance Controlled WT" simulator, which the simulator saves in the directory: C:\WFS_Datalog\Rotor Resistance Controlled WT, the Profile definitions for this data are saved in the directory C:\WFS_Datalog\Rotor Resistance Controlled WT\layouts\.

If data files not created by LdP simulators are to be used, for example, CSV files from a spreadsheet, it is advisable to group these data files in a specific directory and give it a meaningful name. When a Visualization Profile is defined for that dataset, this application will save them in the layouts subdirectory, under that directory.

3.3 Importing Visualization Profiles used in a Simulator configuration

When you want to visualize data from sessions carried out with LdP simulators, a good idea is to start by emulating the StripRecorder Panels that allow visualizing the evolution of groups of signals during the execution of simulations. These groupings are described in the configuration files (conf) of each simulator. They are generally found in the directory C:\ACMSL\WindFarmSimulator\conf. This function imports all Panels and will create the corresponding Profiles, which will be available for selection.

3.4 Creating a new Visualization Profile

To create a new Profile, you must first open a data file, since you need to assign signal names to it, which logically must exist.

When you press the "New" button, a form will appear to enter the name of the new Profile.

The chosen name should ideally be minimally descriptive of the Profile's objective: in this case, we are interested in visualizing the evolutions of the power generated by a wind turbine, how it relates to the wind and to the revolutions of the electric generator.

On "Accept" the editing form for the recorders and their properties of the new profile will appear

And it will be ready to insert recorders into this new profile.

3.5 Adding Recorders to a Visualization Profile

Pressing "+Recorder" brings up the form

In this example, we have assumed that we want to see the Wind variable in the first recorder, hence the chosen name, which is added to the "Profile in edit" form. Immediately the "Recorder properties: Wind" form is presented, to be able to continue adding the corresponding signal.

Regarding the recorder parameters, we can leave the default values and proceed to add a signal to this recorder. To do so we press the "+Signal" button: the application will show the "Select signal" form. (See next figure)

3.6 Adding Signals to a Recorder

The program presents the set of signals available in the log file that we have open.

In this form we look for the signal we are interested in, corresponding to the Wind.

Pressing Accept, it will be added to the Recorder properties form.

This signal corresponds to the value of the Wind Vane. We may also be interested in knowing the effective wind incident on the plane of rotation of the blades, which takes into account the misalignment of the Nacelle. This signal is calculated internally in the Controller, and is available as "Controller.Control.EffectiveWind".

We see that both signals have been added with the same characteristics (Color, Width, Marker)

3.7 Graphical representation of Signals

We can change the graphical characteristics by pressing "Edit selected signal", having previously selected it. The "Edit selected signal" form will appear

4.1 Hardcopy

Pressing the "F12" key generates a PNG image, like the following, insertable into any Office document.

4.2 Accessing the data of the Visualization Profile signals

We can have access to the data of the signals in a given Profile, in the time interval being visualized. To do so:

• Choose the area of interest.

• Press the "Data Access" button: a list of all the signals being presented in the current Profile appears.

• Select the signal whose recorded data we want to know.

• Press View Records, and the Records form appears showing the instants of each record, and the value of the signal at that instant.

• In that form, the record corresponding to the cursor instant is presented in a synchronized way.

• If you press the CSV button the following message will appear

which informs about two important characteristics of the CSV file that will be generated. The next figure shows the beginning of the (single) spreadsheet generated in the CSV file produced, and viewed in LibreOffice.

4.3 Exports

Pressing this button, the program will present the Export form, which will allow us to generate data files in formats suitable for processing in other applications.

The functionalities accessible through this form allow exporting the data of the signals being viewed, in the time range being viewed. The options for the generated file are:

• Which data is exported:

  • Unified data
  • Sampled data

• The format of the output file can be

  • SQLite database type (binary)
  • CSV (Comma Separated Value) file (text)
  • With SQLite format, data processing can be done so that
    • all records can be sent to the output file, or
    • sampling can be done with a Fixed period, whose interval is selectable.

The interest in using these functions derives from the convenience of having smaller data files in time ranges of particular interest. See further ahead the structure of these types of files.

5.1 Datalogging data format of Simulators built with LdP

The files generated by ACMSL real-time simulators store information in an optimized way to reduce size and preserve temporal resolution. Their most significant characteristics are:

• they are usually SQLite database files,
• each signal has its own table,
• the instants are stored with high temporal resolution,
• there is not necessarily a uniform periodic sampling,
• and the records are oriented towards value changes rather than fixed sampling.

This format is particularly suitable for studying events, maneuvers and transients.

5.2 Unified format

The data from an LdP datalogger file can be used by external applications, since it is a format that implements the concepts of "Relational Databases", explorable and modifiable with standard SQL statements. To facilitate its use with common tools, such as spreadsheets, this application also allows generating files with a relational database table structure, but one that has only one date field, and one additional field for each signal to be exported.

Additionally, it may be interesting to have a unified structure where the instants corresponding to each record correspond to periodic sampling. This mode implies loss of temporal resolution (i.e., we will lose some records), but can greatly facilitate data processing for certain functions.

The application also accepts unified files, in which:

• there is a single data table,
• the temporal column is common,
• and each signal appears as a column.

This format is useful when the set of variables has already been previously consolidated for joint analysis.

5.3 CSV Format

This format is the common one for exchanging data between spreadsheets and also between dissimilar databases.

The content of CSV files acceptable for presentation in this program has a logical structure identical to the Unified Format, i.e.:

• A single table
• This table must have:
  • a column that must be called "Date", with type Double, and with a range of values compatible with a date (Excel, or LdP)
  • one column per signal, with type Double for analog signals, or Integer (with values only "1" or "0") for digital ones.

By accepting this type of format, this application can be used as a presentation and analysis tool for calculations performed in other tools

6.1 Visualization Profile

The concept of "Visualization Profile" keeps in a file: which signals are presented, the details of their presentation, and how they are distributed on screen, and therefore allows managing various ways of visualizing the data of a given time series file. It allows:

• grouping certain signals according to criteria of:
  • subsystems or functional blocks,
  • being able to visually compare their values,
  • studying their precedences,
• reusing an already prepared work structure.

6.2 Recorder

A Recorder is a graphic area of the application form where one or more signals are drawn. Each Recorder can contain:

• a single signal
• several analog signals
• several digital signals

Each Recorder has a Scale for the ordinate axis (Y). And it also draws a set of horizontal lines, in a diluted color so they do not cover the

6.3. Recorder Panel

When there are many signals to observe, the goal of a Profile is not to show them all, but to show what is important clearly. It is advisable to group signals following functional criteria, for example:

• input and response,
• setpoint and controlled variable,
• command and feedback,
• state and condition,
• cause and effect.

Practical recommendations:

• do not mix too many signals without direct relation,

• separate different functional blocks into different Recorders,

• reserve specific Recorders for digital signals when they help explain events,

• and group in the same Recorder only signals whose visual comparison adds value.

6.4. Visualization Profiles similar to those used in LdP Simulators

The simulators running in the LdP framework allow the visualization, in real time, of the evolutions of chosen internal signals. This presentation is done with a methodology similar to that of the Recorders in this application, and they are defined in the simulator configuration file, which allows the user to observe the evolution of the Profiles defined for the simulators, which allows maintaining the same visual organization used in Simulator Practical Classes. It also allows creating custom Profiles, more adapted to a specific analysis need.

7. Basic usage procedure

A typical use can follow this order:

1. Open the data file.
2. Identify the input format.
3. Select an existing Profile or create a new one.
4. Organize signals into Recorders.
5. Adjust the representation mode of each signal.
6. Visualize the temporal evolution.
7. Analyze patterns, changes, delays and relationships.

In practice, this flow is rarely done only once. The usual approach is to iterate:

1. visualize a first version,
2. discover which signals are missing or superfluous,
3. adjust the Profile,
4. visualize again,
5. and repeat until achieving a view that responds well to the technical question to be resolved.

10. Signal representation modes

In general:

• analog signals are shown as traces or curves,
• digital signals are shown as discrete states or steps,
• and several signals can share a Recorder if the comparison is useful.

For each signal, in each Recorder where it is used, aspects such as these can be adjusted:

• color,
• line width,
• use of markers,
• and the way points are joined.

The choice is not only aesthetic. A good representation:

• better separates what is important from what is secondary,
• avoids false visual continuities,
• and helps to quickly recognize transitions, permanences and regime changes.
  The drawing detail window allows changing these parameters to improve readability:

11. Vertical scale in each Recorder

When there is more than one signal in a Recorder, or we have only one but it has areas with very different absolute values, and other areas with small variations that are of interest, it is necessary to adjust the scale and offset value to the interval being explored, so that these small variations can be easily appreciated, throughout the time interval of interest.

This application is designed so that it is easy to focus on time intervals where we suspect changes that may reveal interesting information, and therefore allows very fast zooms and temporal scrolling. In that situation, to avoid having to manually adjust the scale values for each change in the time interval of interest, the scale and offset of each Recorder can be set to *Auto-scaling mode. Each Recorder is designed to allow a quick and useful reading of the signals it contains.

12. Statistics of visualized signals and access to their values (Statistics form)

Sometimes it is useful to have the data of the signals being visualized, as an alternative to accessing the original data and performing an extraction using SQL statements or similar.

The application has a Statistics form, accessible by pressing the Data Access button, where grouped data about the signals of the Profile being used are presented, including:

• minimum and maximum dates within the visible section,
• minimum and maximum values, - signal type,
• and number of records considered.

In this form a specific signal can be selected

and open the Records form for that signal, by pressing the View Records button.

13. Exports

The Exports button presents the Export form which allows exporting the data being viewed at that moment. The purpose of these exports is to pass the data from the file being visualized to formats common with other applications. It allows choosing:

• the output format, i.e., the file type,
  
• what data is exported

The selectable file types are:

• Unified SQLite
• CSV

Regarding data, there are two possibilities:

• all original data, but in a single table containing all the dates from all tables,
• one field for each signal, with values interpolated for those instants that do not exist in their original table

In both cases, the export is limited to the time window being visualized at that moment.

15. Analysis best practices

To get the most out of the program it is advisable to:

• always work with a common temporal reference,
• start with a general view and then move to the detail,
• not assume causality without checking the temporal sequence,
• use the Profile as a working tool, not just as a presentation,
• refine the view as the system is better understood.

It is also highly recommended to:

• keep a general Profile for quick orientation,
• create specific Profiles for recurring problems,
• document Recorders with clear names when a Profile is going to be reused,
• avoid simultaneous changes to too many options if you later want to understand what really improves the reading.

15. Summary

LdP_Datalogger_Viewer is designed for:

• exploring long time series,
• loading data from SQLite and CSV files,
• organizing data visualization forms (signals) adjusted to specific objectives Visualization Profiles,
• these Profiles:
  • group signals in Recorders to facilitate their comparison.
  • allow presenting the data in different ways (with/without markers, colors)
  • facilitate the visual interpretation of many signals.

To understand how a system evolves from its signals, this application is oriented precisely to making evident what the data alone do not show clearly. The most effective way to take advantage of it is to combine:

• a careful selection of signals,
• a clear organization in Recorders,
• Profiles adapted to the study objective,
• an orderly temporal reading of events, states and responses.

1.1 Files generated by Simulators in the LdP framework

The simulators generate log files with the evolution of the internal and external signals used in the simulation sessions. These log files are SQLite database files, which contain one table per signal. The table name is the signal name, and it has two fields:

1. Name of the date field: Date, REAL format. Contains the date with resolution of tenths of a millisecond.

2. Name of the signal Value field

   1. For analog signals: ValueA, REAL type

   2. For digital signals: ValueD, INTEGER type

This design is optimized to maximize temporal resolution, since it adds a record only each time there is a change in the corresponding signal. In contrast, sampling at a constant frequency adds one record per clock tick, whether or not the signal value has changed.

These files can be read and used with many freely available applications (SQLiteStudio, DB Browser for SQLite, etc.) since these tools allow using SQL language.

The next figure shows the (partial) structure of one of these log files.

The next figure shows the initial content of one of these tables.

Generally, these SQLite file managers have functions that allow exporting the content of a table in CSV format. See next figure.

1.2 Unified data files generated by LdP_Datalogger_Viewer

The LdP data format is the initial format used by this application. However, it is a format not easy to use in calculation applications, where it is common to have data grouped by date: i.e., each record contains a date and all the signal values for that date.

This application generates data in this format, which we call unified format. See next figure.

and in the next one a detail of the content of the generated table (Data)

There is a variant of this approach that consists of resampling the data at a periodic frequency: i.e., the "Date" field is not taken from the original LdP files, but is generated uniformly from the start of the file, with a fixed distance between them (sampling period)

1.2 'Time-unified data' files generated by LdP_Datalogger_Viewer

This format is designed to facilitate processing by applications that require all signal data to have a common date for each record, across all signals. The LdP format has one table per signal, and its "Date" field corresponds to a change in that signal. This format is very versatile for data acquisition, but for its exploitation and study it is more convenient to have this data in the form of a single SQL table with a single date column (field), and as many columns (fields) as there are recorded signals.

There are two procedures for creating this type of SQL tables:

1. With one record for each instant (field "Date") from each and every one of the data tables, and with the values of each field calculated from the values in their corresponding tables: these values have to be interpolated.
   
2. Having records corresponding to a periodic sampling. The output format of these files is also SQLite.