LGraph2 Multi-channel recorder

Free distributed LGraph2 software is designed for recording, visualization and processing of analog signals recorded with the help of measuring boards or ADC modules manufactured by L-CARD.
LGraph2 in combination with the L-CARD module or ADC board will turn your computer into a measuring laboratory, replacing devices such as voltmeters, recorders, oscilloscopes, etc. Below is a brief description of the features of the program.
All comments and suggestions on adding and changing functions are welcomed at en@lcard.ru.


1. Data acquisition
2. Visualization of registered data
3. File operations and working with blocks
4. Data processing
5. Additional features
6. Plugins

Download version 2.34.59 (17 MB, 20.06.2017)
Download description (lgraph2_help.pdf, 6.5 MB)
Download plugins description (lgraph2_plugins.pdf, 399 kB)
Download version history (lgraph2_readme.rtf, 108 kB)


1. Data acquisition

The main features of signal recording

многоканальный регистратор, самописец, визуализатор аналоговых сигналов

  • Unlimited recording size (limited only by free disk space)
  • Multi-module operation mode (simultaneous registration from different modules)
  • Any recording speed
  • The ability to write to RAM
  • Recording the specified number of ADC channels (up to 32)
  • Synchronization of registration by level, by synchro-start, by computer clock, GPS synchronization
  • Visualization during data acquisition
  • Changing the visualization parameters during registration
  • Ability to write many implementations into one file
  • Support for L-502, L-780M, L-791, L-783M boards, E-502, E-154, E14-140, E14-140M, E14-440, E20-10 external modules, LTR11, LTR114, LTR24, LTR27, LTR212, LTR22, LTR51, LTR210, LTR41, LTR42, LTR43 modules
  • Convenient export to Matlab using *.m scripts generator


Multimodule registration mode

визуализация аналоговых сигналов во время регистрации

LGraph2 provides the possibility of simultaneous work with several measuring modules.
  • Support for simultaneous operation of up to 100 items produced by L-CARD
  • Visualization of data obtained at different frequencies from different modules
  • Simultaneous data input from various LTR modules and USB modules
  • Synchronous start of modules within a single LTR-EU crate
  • A simple data file format makes it easy to import multimodule entries into external programs (Matlab, Origin, etc.).


Visualization during data acquisition

визуализация аналоговых сигналов во время регистрации

LGraph2 provides the ability to display the data from ADC without interrupting the acquisition.
  • Ability to change the X scale during data acquisition
  • Ability to change the Y scale during data acquisition
  • Choosing any X scale
  • Possibility of pause of recording with keeping visualization of analog channels


Serial and scheduled registration

запуск АЦП по расписанию

In addition to the common mode of data entry into a single file, LGraph2 supports special recording modes:
  • Data input on a schedule. The program can start the input of data from ADC to a file according to the schedule, and you can specify several time marks, and upon reaching each one LGraph2 will start to enter data into a new file.
  • Serial launch. The user determines how many times it will be necessary to start the input, and determines the pause between the input sessions, after which the program itself performs the required input sequence (at the user's choice, each implementation is either written to a separate file or the whole sequence of implementations is written to one file).
  • Periodic saves. In this mode, after starting the input, the program performs continuous input, but after reaching the user-defined interval, the program closes the file into which the input was made and starts to record the new file. This mode is convenient when you need a long input, when you need maximum reliability: when turning off or hanging the computer, most of the data entered does not disappear.
  • Since in additional input modes, as a result, many data files are created, the program provides a number of settings that determine the automatic generation of file and folder names. In particular, each series of files can be placed in the new folder being created, and the file name can be formed both on the basis of the increasing index, and by adding the current date and time to the file name.



режим предварительного просмотра

You can start data entry in preview mode. The data will not be written to the file, but will only be displayed on the screen in graphs view. The user can press the "Record" button at any time, after which the data will begin to be written to the file. In the new version of the program, the data in the preview mode is stored in a circular RAM buffer (the size of which is determined by the user). If the user presses "Stop" (without running "Record"), the data stored in the preliminary buffer viewing, will be available for display and saving in a file. This feature enables the user to track the event and save the data not only following the event, but also preceding it.


Multiple implementations recording into one file

запись нескольких реализаций АЦП в один файл

After starting the data recording, the process can be paused at any time with the PAUSE button (the data display continues on the screen). Pressing the PAUSE button again will resume data recording. Subsequently, a group of segments can be combined into one segment. It is also possible to delete any number of individual segments from the file.

2. Visualization of registered data

Convenient scale selection along the X axis

произвольный масштаб X

  • Convenient choice of time scale. Now, regardless of the sampling frequency of the ADC, the user can set any scale on X axis, so that one scan screen can correspond to a scan from 6 μs to almost any time (at least a few days).
  • The history of scaling in the X-axis is implemented, in which the last 16 scales are saved, so that the user can select any of the last 16 scales by one mouse click.
  • Now you can change the scale simply by clicking on the time markings under the X axis on the screen.
  • A choice of seven possible dimensions of the X scale: from microseconds to absolute time, when time marks under the X axis are output in the format hh:mm:ss:ms, day-month-year.


Multiple windows

многооконный регистратор АЦП (USB, PCI)

  • The program allows you to display data from ADC by graphs in several windows, the number of which is determined by the user himself (from 1 to 8). In any of the windows you can display several graphs of your choice.
  • The dimensions of the windows can be easily changed by moving the mouse between the windows vertically.
  • To adjust the parameters of each window just right-click on the desired window; a short menu for setting the window will be displayed immediately, and any change of parameters in the window's setup menu will be immediately visible on the screen.


Convenient display settings for each channel

удобные настройки визуализации каналов АЦП

  • Values ​​from ADC can be displayed both in volts and converted into physical quantities using individually specified calibration coefficients for each channel.
  • Many options for customizing the graphics for each channel (color, line width, line type, ADC sample marker type). The program has a legend, located near to the window, in which the graphs are displayed. By right-clicking on the desired graphs in the legend, the user can quickly and conveniently change the graphic settings of displaying the specified channel.
  • To view specific signal values, you can turn on the cursor, whose graphical parameters are also set by the user.



анализ данных

  • You can select a special window, in which the magnifier function is implemented for easy viewing and analysis of data.
  • In the magnifying glass window, in addition to the enlarged image, there are two cursors, with which you can perform time and amplitude relative measurements.

3. File operations and working with blocks

Export to text and binary formats

экспорт данных АЦП для Excel, MatLab и т.п.

The program saves data files in binary format. To convert them to text format for viewing in text editors or processing in Excel, Matlab, etc. the data export window is intended. An additional convenience of processing is the ability to export data (taking into account all the scaling factors) into binary files that can be used in user programs or directly imported into Matlab, Origin and the similar software.
  • When exporting data can be represented in ADC codes, in volts or converted with user coefficients.
  • When exporting, the user himself determines whether the whole file will be exported or only the specified part of it.
  • If necessary, you can enable the addition of a time column to the exported file. Then each data line will start with the time mark of the given frame.
  • When exporting, you can control the accuracy (the number of decimal places) from which numbers will be displayed.


Working with block

удобная работа с блоком аналоговых данных

  • You can select a data block either using the menu or using the mouse (a combination of the right mouse button and Shift on the keyboard), .
  • The selected block can be saved as a separate file or deleted.
  • The boundaries of the selected block can be used in the processing windows when plotting a spectrum or a histogram.
  • The boundaries of the block can be conveniently moved with the right mouse button.

4. Data processing

Spectrum analyzer

бесплатный спектроанализатор

  • The program implements a separate window for calculating the energy spectrum of the recorded signal.
  • Different versions of the window superimposed on the signal before the calculation of the spectrum.
  • Calculation of up to 64 harmonics with the display of peaks on the graph. Auto detection or manual input of the fundamental frequency for harmonic analysis.
  • The calculated spectrum can be exported to a text file.



многоканальная гистограмма

  • The program has a separate window for calculating histograms.
  • It is possible to build two histograms on different channels and display them in one window.
  • Histograms can be exported to a text file.

5. Additional features

GPS синхронизация

  • LGraph2 supports command-line control. When loading, in command line you can specify a file with the settings *.grb or a file with data that will be loaded after the program starts. Also, using the command line, you can set the automatic start of registration mode after the program is started.
  • GPS synchronization. The launch can be configured from the time received from satellites via GPS system. It is necessary a GPS receiver should be connected to the computer, and the parameters of receiver should be specified in a special window. In case of connection one of the ADC channels to the output of a second GPS mark, you can provide synchronous data input from devices located far apart.
  • The program interface supports two languages ​​- Russian and English.
  • The program provides the possibility of asynchronous control of DACs and digital outputs.
  • The program has a special event search panel in analog channels, with which it is possible to quickly and easily find the points at which the signal or its derivative exceeds a given level.
  • Export of graphic windows to bmp format is realized.

Export to Matlab

экспорт в Matlab

To simplify the reading of data files from the popular package, a Matlab script generator has been added in LGraph2:
  • The generated *.m script allows the user to retrieve the data from the ADC in Matlab, represented as a two-dimensional matrix, converted into physical quantities with all calibration coefficients taken into account.
  • The program has the ability to enable the automatic generation of *.m scripts each time a data file is created.
  • An example of Matlab script:
    clear all
    close all
    format long
    DataFileName='c:\LW\LGRAPH2\test_E-14-140M_1R897344.dat'; % Data file name (dat)
    ShowInfo = 1; % Show an information about data file

    module_name = 'E-14-140M'; % module name
    time_string = ' 15-02-2010 09:50:16';% date and time of data input start
    chan_max = 32; % common number of channels for selected module
    RealChannelsQuantity = 2; % number of entered (active) channels
    RealKadrsQuantity = 32768; % number of frames collected in 'int' format ( < 2.147.483.648)
    RealSamplesQuantity = 65536; % number of samples collected in 'int' format (<2.147.483.648)
    TotalTime = 3.276800; % time to enter in seconds
    AdcRate = 10000.000000; % frequency of ADC in Hz
    InterkadrDelay = 0.005000; % interframe delay in ms
    ActiveAdcChannelArray = [0 1 ]; % array with the numbers of input channels (from zero)
    AdcGainMax = [8192.000000 8192.000000 ]; % array with an upper range of ADC channels
    AdcGainMin = [-8192.000000 -8192.000000 ]; % array with a lower range of ADC channels
    CalibrScale = [1.012720 1.007321 1.003053 1.002149 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 ]; % array with scale calibration factors
    CalibrOffset = [1.212723 0.726175 -0.000225 -1.126492 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 ]; % array with zero offset calibration factors
    UserCalibrScale = [1.000000 1.000000 ]; % array with user-defined scale calibration factors
    UserCalibrOffset = [0.000000 0.000000 ]; % array with user-defined zero offset calibration factors
    DataCalibrScale = [0.001236 0.001236 ]; % array with scale conversion
    DataCalibrOffset = [0.000000 0.000000 ]; % array with zero offset transformation
    DataCalibrZeroK = [1.212723 1.212723 ]; % array with zero offset
    if ShowInfo == 1 % Show file information
    format short
    disp('Data format parameters:')
    disp([' Module name : ' module_name]);
    disp([' Number and time of data entry: ' time_string]);
    disp([' Number of active channels : ' num2str(RealChannelsQuantity)]);
    disp([' Number of frames collected : ' num2str(RealKadrsQuantity, 9)]);
    disp([' Number of samples collected : ' num2str(RealSamplesQuantity, 9)]);
    disp([' Input time : ' num2str(TotalTime, 9) ' c']);
    disp([' ADC frequency : ' num2str(AdcRate, 9) ' Гц']);
    disp([' Inter-frame delay : ' num2str(InterkadrDelay, 9) ' мс']);
    fid = fopen(DataFileName, 'r');
    fseek(fid, 0, -1);
    [y NSamples] = fread(fid, 'int16');
    y = reshape(y, RealChannelsQuantity, RealKadrsQuantity);
    for i = 1:RealChannelsQuantity;
    t = linspace(0,TotalTime,RealKadrsQuantity);
    y(i,:) = (y(i,:)+DataCalibrZeroK(i))*DataCalibrScale(i)+DataCalibrOffset(i);
    figure(i),plot(t,y(i,:),'y-'),grid on;
    ylabel('U, V');

6. Plugins

измерительные плагины

In order to provide the user the ability to implement specialized algorithms for processing and displaying data that are absent in LGraph2, the program implements the mechanism for connecting external plug-ins. In fact, the plugin is a DLL library, which should contain the functions by which LGraph2 (at the time of data acquisition, as well as during file browsing) transfers the data to the plug-in from the ADC and accepts new, calculated in the plug-in data for visualization on the screen and saving to a file. LGraph2 distribution includes the most typical plugins developed by L-CARD, which can be used both as complete devices and as samples for adding specific features into them.
The plugin connection mechanism provides:
  • Simultaneous connection of several plugins.
  • Ability to display data in multimetric elements form (thermometer, tank, etc.).
  • Perform real-time calculations during data acquisition.
  • Realization of algorithms with feedback (control of DACs and TTL lines during data acquisition).
  • Constantly replenished library of plugins.
  • Easy implementation of the plugin.
  • Ability to create calculation channels that can be saved and viewed as standard LGraph2 data files.
  • Saving the values ​​of all visual elements to a text file in log mode (automatic addition to the end of file).

List of supplied plugins:

Multimeter Multichannel multimeter, calculating the average value, dispersion and frequency over analog channels.
Filtering and decimation Multichannel IIR filters that perform real-time filtering with the possibility of subsequent decimation. It is possible to specify the type of filter, order and factor of decimation.
Extended filtering and decimation Multichannel IIR filters that perform real-time filtering with the possibility of subsequent decimation. It is possible to specify the parameters of three groups of filters, each group consists of two series-connected filters. For each channel, a group of filters is specified, which allows you to set different filters for channels.
Two-channel spectrum analyzer Real-time dual-channel spectrum analyzer.
Window discriminator The plugin was originally intended for automatic determination of R-R intervals in an electrocardiogram. However, it also allows you to select peaks with certain parameters in the stream of any data and to calculate the distance between them.
XY oscilloscope An oscilloscope that displays data from one input channel relative to another. It has additional parameters for displaying Lissajous figures.
XY recorder XY recorder, designed to obtain the current-voltage characteristics.
SCADA-like visual elements A plugin that demonstrates realized visual elements (such as a thermometer, a tank, etc.).
Adder and differentiator A plugin that creates two new channels from two channels: the sum of two channels and the derivatives on two channels.
An example of a simple plugin in Delphi6 A plugin that demonstrates work in Delphi. The plugin reduces the frequency by half.
An example of a simple plugin in Borland C 5.02 The plugin demonstrating work in Borland C 5.02. The plugin implements the function of the simplest XY oscilloscope.


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Fax: +7 (495) 785-95-14

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Technical support: en@lcard.ru

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Russian Federation

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