NOVA Technical Note 6 - Automatic Data Recovery XNOVA 1.10x

8/18/2019 NOVA Technical Note 6 - Automatic Data Recovery XNOVA 1.10x

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NOVA Technical Note 6

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Automatic data recovery

Case study: storing data during long measurements?

1 – Storing data in NOVA

In NOVA, all the measured data points are stored in a single .nox file at the end ofthe measurement. The .nox file is generated in the user-defined database and itcontains the measured data points as well as the procedure that was used in theexperiment. The benefit of this automatic storage system is that themeasurements can be performed without time delays due to reading or writing ofdata onto the computer hard drive. The drawback is that the data points can belost if the computer crashes or if the power fails during the measurements.

For very long measurements, it is convenient to save the data while theexperiment is running. The Export ASCII data command can be used for thispurpose. This command can be used to export measured data points or analysisresults to a .txt file. This technical note illustrates how to use the Export ASCII data command using different practical examples on the dummy cell.

2 – The

Export SCII data

command

The Export ASCII data command can be found in the data handling group ofcommand (see Figure 1). Since this command is not a measurement command, it

can be added anywhere in the procedure, except inside a Timed procedure command.


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NOVA Technical note 6

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Figure 1 – The Export ASCII data command is located in the Data handling group of

commands

To illustrate the use of the Export ASCII data , the Autolab Cyclic voltammetrypotentiostatic procedure will be used. Several situations will be explored in thistechnical note, all of which can be performed on dummy cell (a).

Load the Autolab Cyclic voltammetry potentiostatic procedure into the procedureeditor to get started. To use the Export ASCII data command, drag and drop it atthe end of the procedure (see Figure 2).


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Figure 2 – Adding the Export ASCII data command to the procedure

The Export ASCII data command has the following command parameters:

• Filename: provides the name and the location of the file1.

• Number of columns: defines the number of columns in the file.

• Column delimiter: defines how data from two consecutive columns areseparated from one another (Tab, space, comma, etc…).

•

Decimal separator: defines which symbol should be used to separate theintegral part of the values from the decimal part.

• File mode: defines how the data points should be saved in the ASCII file(s).This technical note will explore this parameter in detail. The possiblesettings are: Overwrite , Append and Make unique .

• Remarks: this remarks field can be added to the output file, forbookkeeping purposes.

• Write column headers: yes/no – defines if the signal names should beadded as headers in the ASCII file.

1 Note: the folder in which the file will be created must exist on the disk.

Note

The symbol is shown next to the Export ASCII data command because thefilename parameter is not yet linked.


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• Column 1 .. n: the parameters are linked to the values to export (n is thenumber of columns defined in the command).

2.1

– Exporting data from a single measurement

In this example, we will illustrate how to use the Export ASCII data command toexport data points from a single measurement. For this purpose, first create a newfolder, called Exported data, on the C:\ hard drive.

Add the Export ASCII data command to the Autolab Cyclic voltammetrypotentiostatic procedure as illustrated in Figure 2. In this example, the values ofthe Potential applied, WE(1).Current and time will be exported to a single file.

Set the number of columns to three. Using the links, create a link between

Column 1 in the Export ASCII data command and the Potential applied signalprovided by the CV staircase command (see Figure 3).

Repeat the same for the WE(1).Current signal and the Time signal. Set the columndelimiter to ‘Tab’ and leave the File mode unchanged (Overwrite).

Figure 3 – Linking the signals to the Export ASCII data command


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Next, click the button next to the Filename parameter and define a path and afilename for the output file (see Figure 4).

Figure 4 – Defining the location of the output file C:\Exported data\Example 1.txt)

With the three columns linked to three signals provided by the CV staircasecommand and the output file defined, it is possible to add a remark beforestarting the measurement.

Click the button next to the Remarks parameter to open the Remarks editor

window and add a useful comment (see Figure 5).

Figure 5 – Adding a remark to the output file

Connect dummy cell (a) and press the start button to begin the measurement. Thetypical cyclic voltammetry for the dummy cell will be plotted in the measurementview. After the measurement is finished, the data will be available in the database,as usual, but an additional .txt file will be available in the C:\Exported data folder.This text file can be opened with Notepad (see Figure 6).

Note

The path must be valid.


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Figure 6 – The data points recorded during the cyclic voltammetry measurement

Press the Start button again. Before the measurement starts, a warning will bedisplayed. Since the File mode parameter is set to overwrite, the software can usethe same output file again, unless the user presses the Close button during theprocedure checking (see Figure 7).

Figure 7 – A warning is displayed during validation


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Pressing the OK button will validate the procedure and the measurement willproceed. At the end of the measurement, the data points in the Example 1.txt filewill be overwritten.

2.2

– Exporting data from a measurement and from data analysis

As a second example, the same procedure will be used, with the addition of adata analysis command. In this example, the SG Smooth command will be used inorder to smooth the data obtained during the CV staircase measurements (seeFigure 8).

Figure 8 – Adding the SG Smooth command to the procedure

The SG Smooth command can be setup in order to smooth WE(1).Current values.This requires linking of the Potential applied and WE(1).Current signals to theInput X and Input Y, respectively (see Figure 8).

Add two new Export ASCII data commands at the end of the procedure and usethem to create new text files (see Figure 9).


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Figure 9 – Adding a new Export ASCII data to the procedure

Set the number of columns to two and link them to the Result X and Smoothedresult Y provided by the SG Smooth command. The other parameters will be keptidentical to the previous Export ASCII data command.

Connect dummy cell (a) and start the measurement. The typical CV staircaseprofile will be displayed in the measurement view. At the end of the

measurement, two files will be added to the Exported data folder (see Figure 10).

Note

To avoid confusion with the previous files, the output files have been set toC:\Exported data\Example 2 data.txt and C:\Exported data\Example 2smoothed.txt , respectively.


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Figure 10 – Two new files are added to the Exported data folder after the measurement

2.3 – Exporting data from a long measurement

In the third example, we will illustrate how the Export ASCII data command can beused in long measurements. Reload the Autolab Cyclic voltammetry potentiostatic

procedure and add the Export ASCII data command as described in the firstexample (see Figure 2).

Set the File mode parameter of the Export ASCII data command to ‘Make unique’and change the file name to C:\Exported data\Example 3.txt (see Figure 11).


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Figure 11 – The procedure used in the third example 1/3)

Locate the Repeat n times command in the Control group. Drag and drop this

command at the very end of the procedure editor (see Figure 12).

Figure 12 – Adding the Repeat n times to the procedure 2/3)

Using the ‘Drag and drop’ method, select all the measurement commands at thetop of the procedure editor and move it into the Repeat n times. Repeat the same

for the Export ASCII data command. All the command should now be locatedinside the repeat loop as shown in Figure 13.


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Figure 13 – The final procedure used in the third example 3/3)

Connect dummy cell (a) and press the start button. The potentiostatic cyclicvoltammetry measurement will be performed ten times in a row. At the end ofeach cyclic voltammogram, a .txt file will be added the to the Exported data folder(see Figure 14). The files are created while the measurement is running andwriting the data to file does not interfere with the timing of the experiment.

Note

Figure 14 shows the contents of the Exported data folder after threerepetitions. The first file is called Example 3 data.txt , the consequent files arecalled Example 3 data(n).txt , where n is a counter that starts at 1,automatically.


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Figure 14 – The exported data files are created while the measurement is running

At the end of the measurement, a total of 10 unique Example 3(n).txt files shouldbe available in the Exported data folder.


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2.4

– Exporting data from a long measurement into a single file

In the final example, we will illustrate how the Export ASCII data command can beused in long measurements. The same procedure as will be used but this time theFile mode parameter will be set to ‘Append’.

Figure 15 – The final procedure used in the fourth example

Change the name of the output file to Example 4 data.txt. Connect the dummycell (a) and press the start button. At the end of each cyclic voltammogram, therecorded data points will be added to the specified ASCII file. At the end of themeasurement, this file will contain all the recorded data points.

3

– Conclusion

Using the Export ASCII data command provides an additional safety for usersperforming very long experiments. Even if the power fails or if the computercrashes, the measured data points will still be available in a .txt file.

Note

Storage of data points into an ASCII file is performed whenever the software

encounters the Export ASCII data command.

NOVA Technical Note 6 - Automatic Data Recovery XNOVA 1.10x

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