PVI
Time-Controlled DC-Measurements
Controller program for the pre-treatment of probes Data aquisition software for electrochemical
applications Time controlled potentiostatic & galvanostatic methods
© Zahner 11/2008
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1. General ___________________________________ 6
2. Start of PVI ________________________________ 8
2.1 The Main Menu ________________________________________________ 8
2.2 The Submenus ________________________________________________ 9
2.2.1 Define Setpoints____________________________________________
2.2.2 System Parameter __________________________________________
2.2.3 Execute ___________________________________________________
2.2.4 Evaluation_________________________________________________
2.2.5 Setup IM6 _________________________________________________
2.2.6 CONCAP __________________________________________________
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3. The PVI Editor - < Define Setpoints > _________ 10
3.1 Splitting the Memory Into Partitions - < MEMORY > _________________ 10
3.1.1 Reserve Memory for Setpoint List - < SPts > ___________________ 11
3.1.2 Reserve Memory for 'Internal' Measure Points (E,I,t) - < MPts > ____ 11
3.1.3 Reserve Memory for 'External' Measure Points - < APts > ________ 11
3.2 Define Input Window - < Range & Resolution > ____________________ 11
3.2.1 Define Time Resolution - < Time Resolution > _________________
3.2.2 Select Potential Range - < E-Range > _________________________
3.2.3 Select Current Range - < I-Range > ___________________________
3.2.4 Select Vertical Resolution - < Y-Zoom > _______________________
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3.3 Setup Potentiostat ____________________________________________ 13
3.3.1 Select Active/Inactive Potentiostat - < POTstate > _______________
3.3.2 Select Operating Mode of Potentiostat - < POTmode > ___________
3.3.3 Select Autoshunt or Fixshunt Mode - < I-Range > _______________
3.3.4 Select (E,I,t)-Data Acquisition - < DataAcqu > __________________
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3.4 Editing a PVI Control Sequence _________________________________ 14
3.4.1 Add Corner Point(s) - < APPEND > ___________________________
3.4.2 Numerical Input - < ? > _____________________________________
3.4.3 Change Mode of Operation - < Change Mode > _________________
3.4.4 Edit Corner Point(s) - < EDIT > _______________________________
3.4.5 Delete Existing Corner Point(s) - < DELETE > __________________
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3.5 Clear PVI Control Memory - < CLEAR C-DATA >____________________ 17
3.6 Setup Data Acquisition (Optional ANDI-Amplifier Modules) __________ 17
3.6.1 Select Active Channels _____________________________________ 17
3.6.2 Activate Data Acquisition ___________________________________ 18
3.6.3 Define Sampling Frequency _________________________________ 18
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3.7 Modify I/O’s __________________________________________________ 19
3.7.1 Signal Acquisition Setup____________________________________ 20
3.7.2 Save & Load Calibration Factors _____________________________ 21
3.7.3 Check Active Inputs________________________________________ 21
4. Saving & Loading of Control Data ____________ 22
4.1 Load File - < OPEN > __________________________________________ 22
4.2 Save File - < SAVE >___________________________________________ 22
4.3 Creating Repetitive Curves - < SEQUENCES > _____________________ 22
5. System Parameter _________________________ 23
5.1 Reentry to EIS-Program ________________________________________ 23
5.2 Shunt Resistor and Current Range & Limit ________________________ 23
5.3 Current Limit - < LATENCY TIME > _______________________________ 24
5.3.1 Defining an Active Control Window t>0 _______________________ 24
5.3.2 Selection of Immediate Interrupt t=0__________________________ 24
5.3.3 Switching Off Software Current Control t<0 ___________________ 24
5.4 Settling Time _________________________________________________ 25
6. Execute – Select Online Display and Start
Measurement ____________________________ 26
6.1 Selection of Online Display - < SELECT DISPLAY > _________________ 27
6.1.1 'Single'-Scope Display______________________________________
6.1.2 'Double1'-Scope Display ____________________________________
6.1.3 'Double2'-Scope Display ____________________________________
6.1.4 'Triple'-Scope Display ______________________________________
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6.2 Select Input of an Axis - < SELINP >______________________________ 29
6.3 Scaling of Data - < SELGAIN > __________________________________ 30
6.4 Select Window Refresh Time - < SELTIME > _______________________ 30
6.5 Start Measurement - < START MEASUREMENT >___________________ 31
6.6 Stop Measurement - < STOP MEASUREMENT > ____________________ 31
7. Evaluation – Visual Display of the Data _______ 32
7.1 Select Active Channels - < E Chann > , < I Chann > _________________ 32
7.2 Select Scale Type - < E Scale > , < I Scale > _______________________ 33
7.3 Redraw Graphs - < E Redraw > , < I Redraw > ______________________ 33
7.4 Setting of Cursors - < Cursor1 > , < Cursor2 > _____________________ 33
7.5 Magnification of Window - < Zoom > _____________________________ 33
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7.6 Display Whole Measurement - < Total >___________________________ 33
7.7 X/Y-Presentation of the Measuring Data - < XY-plot > _______________ 33
7.8 Select X-Y-Channel - < X Chann > , < Y Chann >____________________ 34
7.9 Select X-Y-Scales - < X Scale > , < Y Scale > _______________________ 34
7.10 Redraw X-Y-Diagram - < XY Redraw > ___________________________ 34
7.11 Return to Time-Representation - < EI-T-Plot >_____________________ 34
7.12 Calculating Integrals ∫E(t)dt / ∫I(t)dt______________________________ 34
7.13 Integration with Baseline ______________________________________ 35
7.14 Printer Hardcopy - < HARDCOPY > _____________________________ 35
7.15 Create ASCII-Data List - < DATA LIST > __________________________ 36
7.15.1 Listing PVI (E,I,t)-Data _____________________________________
7.15.2 Listing ACQ-Data _________________________________________
7.15.3 Control Parameters of ASCII-List Output _____________________
7.15.4 Output of ASCII-List_______________________________________
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7.16 Saving & Loading of Measurement Data - < DiskOps M Data > _______ 38
7.16.1 'load file' - < OPEN > ______________________________________ 38
7.16.2 'save file' - < SAVE > ______________________________________ 38
7.17 Evaluation of Other Time Data _________________________________ 39
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1. General
The PVI program has been developed to fill holes in the already existing EIS software. The programs
at disposal allow the user to record cyclic voltammograms (CV) or steady voltage-current curves (I/E).
CE makes it possible to record general parameter-impedance curves which can be analyzed by
means of various reports, for example, capacity reports or ac polarography. The EIS program, which is
related to impedance spectroscopy, allows to carry out impedance measurements within a wide
frequency range at a given but steady potential or current. Although there is a variety of different
measurement programs, however, not all possible measuring parameters can be selected arbitrarily at
the same time.
The PVI completes the existing software package and enables the user to carry out measurements in
the time domain. Different control and measuring sequences can be aligned in equal intervals. The
PVI offers an almost infinite number of measurement possibilities due to the various modes of the
potentiostat, which can be selected freely. A sequence of PVI elements is created by an integrated
graphic editor. In the following, PVI elements should be defined as individual ramps, which have been
fixed by the corner points <tn,En/In> and <tn+1,En+1/In+1> respectively. Any setting of recording and
output parameters is available.
These are the possible operating modes of the potentiostat:
Mode of operation:
potentiostatic
galvanostatic
Measuring range:
fixes shunt in potentiostatic mode
auto shunt in galvanostatic mode
Data acquisition:
Sampling rate:
on/off
1mHz <= fsamp <= fmax
The maximum sampling frequency fmax is dependent on the selected operational mode and the cpu
unit in use.
Each ramp starts at a certain default data doublet
< time tm, potential Em or current Im >
and ends at the next element
< tm+1,Em+1/Im+1 > .
The starting point of the new element is equivalent to the terminating point of the preceding element.
The editor continuously displays the operating parameters time and potential/current as well as the
slew rate of voltage or current.
During the data acquisition, all operating parameters of the potentiostat are acquired and stored as
data triplets <t,E,I> (time, potential, current), with the measurement of the parameters potential and
current being integrable. The sampling rate which has been determined for the active PVI element is
applied. The impedance measurement system averages ten measuring points continuously. These
internal measuring points are sampled by means of the repetition rate of the output data. The refresh
rate of the output parameters is between 1kHz and 10kHz and is again dependent on the CPU
performance as well as on the operating mode of the potentiostat.
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The maximum usable time domain for a PVI element is 500h, with the mini mum resolution time being
dt=1ms. PVI allows to study
- steady states (dE/dt=0 or dI/dt=0),
- slow changes in states (dE/dt ≈ mV/min) and
- tests with fast pulses (dE/dt ≈ kV/sec).
The measured parameters are shown online in the time window active at this moment. The time
window is described by the default data during each measurement. The user is able to observe the
operating conditions and if need be, he could intervene into the measurement, thus excluding the loss
of data determined by then.
The PVI offers different graphic presentations for the data report. The measuring data is either
represented linearly or logarithmically as E(t) or I(t) plots. A X/Y-representation of the current data
against the potential data is included. User-defined reports, however, are integrable, too.
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2. Start of PVI
PVI belongs to the group of measuring programs named <Time
Domain>. To start PVI activate the icon named time domain and a
further menu will pop up.
Consequently select the icon named <PVI> and confirm. Now PVI will
be started.
2.1 The Main Menu
PVI starts up with a graphical logo including a set of buttons that may be activated by the user. Within
PVI each of the buttons represents a submenu or an i/o-function.
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2.2 The Submenus
The submenus may easily be recognized by their titles and symbols being plotted within the button.
The main menu manages the following submenus, which will briefly be described.
2.2.1 Define Setpoints
- Line editor to define setpoint list
- Selection of mode of operation
- Setup of additional data acquisition
2.2.2 System Parameter
- Setting of software controlled current limiting
- Bandwidth limiting of potentiostat
- Reentry function to impedance program
2.2.3 Execute
- Selection of on-line display
- Selection of on-line data
- Scaling of on-line data
- Start of measurement
2.2.4 Evaluation
- graphical display of measure data
- disc i/o operations of measure data
- various displays
- output to ASCII formatted list
2.2.5 Setup Zennium
- control potentiostat via test sampling of
impedance measurement program
2.2.6 CONCAP
- pi-controller to measure C(E)-curves
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3. The PVI Editor - < Define Setpoints >
The editor input page consists of different regions of interest. Each of the regions
represents a submenu. Parameter and data of interest are shown within reserved output
boxes. The input window is displayed in the middle of the screen. The input window is
scaled to default settings after the start. Starting at t = 0 sec, the time axis runs from the left
to the right. The scales of potential and current values run on the vertical axis.
3.1 Splitting the Memory Into Partitions - < MEMORY >
Depending on the demands of the control sequence the memory being reserved by
the PVI-program may be split into three partitions of different size. The memory
being available for the PVI-program itself depends on the memory partitioning of the
operating system and may be altered by use of the utility program 'konfigur'.
Considering the different demands of PVI-control sequences partitioning of the
memory by the user will become obvious. Steady state experiments at a fixed
potential Eset or at a constant current Iset will require a low number of setpoints and will offer nearly all
memory for data acquisition. Repetitive execution of puls sequences, however, will demand a high
number of setpoints and will reduce the memory being available for data acquisition. Running internal
and external data acquisition in parallel the memory for both types of data may be defined individually
depending on the sampling frequencies fint & fext and on the number of active channels n.
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The three partitions of memory will be set by use of sliding controllers. The upper and the lower limit
will be set in concurrence with the actual fractions and free memory. The total memory being available
will be denoted within the output boxes named <MEMORY>.
The individual memory partitions of setpoints <SPts>, measure points <MPts> and data acquisition
points <APts> will be denoted both in units of percent of the total memory and in units of data points.
The reserved memory will be denoted in units of kByte right to the corresponding slider.
3.1.1 Reserve Memory for Setpoint List - < SPts >
Activate the controller named <setpoints> and move the slider either by moving the mouse or by using
the cursor keys <<> and <>>. The upper limit will be set automatically with respect to the setting of
<MPts> and <APts>. The lower limit will be defined by the actual number of setpoints being used.
Using the HOME-function will reset the measure point memory to the initial value. Choose the new
memory and use the ENTER-function to confirm the new setting.
3.1.2 Reserve Memory for 'Internal' Measure Points (E,I,t) - < MPts >
Activate the controller named <measure points> and move the slider either by moving the mouse or by
using the cursor keys <<> and <>>. The upper limit will be set automatically with respect to the setting
of <SPts> and <APts>. The lower limit will be defined by the actual number of measure points being
used. Using the HOME-function will reset the measure point memory to the initial value. Choose the
new memory and use the ENTER-function to confirm the new setting.
3.1.3 Reserve Memory for 'External' Measure Points - < APts >
Activate the controller named <data acquisition> and move the slider either by moving the mouse or
by using the cursor keys <<> and <>>. The upper limit will be set automatically with respect to the
setting of <SPts> and <MPts>. The lower limit is equal to zero. Selecting no memory at all will disable
the data acquisition of additional amplifier modules. Using the HOME-function will reset the memory of
data acquisition to the initial value. Choose the new memory and confirm by using the ENTERfunction.
3.2 Define Input Window - < Range & Resolution >
Depending on the time resolution of the element to be put in ( e.g. steady state
experiments at Econst/Iconst or recording of fast pulse response signals ) different time
scaling has been prepared. The input range of potential Ecntrl or current Icntrl of the
controlling function may be adapted to the individual demands. By the fine scaling
option <Y-Zoom> the vertical resolution may be increased by a factor of 5 or 25. Using Y-Zoom will
split the vertical axis and increase the vertical sensitivity for input.
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3.2.1 Define Time Resolution - < Time Resolution >
Each time page will consist of 500 steps in horizontal resolution. The actual time resolution will be
marked by a green square right to the selective button of the menu list. To choose a different time
resolution activate the corresponding button and confirm the selection. The time resolution is defined
by the interdependent parameters 'window width' and 'mouse sense'. Both parameters have been
listed on top of the selective buttons. The chosen mouse sensitivity will be put out additionally within
the output box named <X-Res> in the parameter section of the main menu of the graphic editor.
3.2.2 Select Potential Range - < E-Range >
The active potential resolution is marked by a green square right to the selective button of the menu
list named 'E-Range'. To choose a different resolution activate the corresponding button and confirm
the selection. Potential setting will be used to define the output range of a potentiostatic element and
does not affect the resolution of the measured potential.
The potential range must be selected in accordance to the used hardware. Using the internal
potentiostat the output range is limited to a range of dE= ±4V. By use of the buffer amplifier the output
range may be extended up to ±10V (±20V-Range ). The ±40, ±80V and ±120V options have been
prepared for use with the compliance voltage booster CVB80 or CVB120 only.
Each vertical page will consist of 320 steps in resolution being symmetrical to the middle of the page
(offset during input). The potential re solution is defined by the interdependent parameters 'Y-Fac' and
'Y-Res'. Selecting an E-Range (Y-Fac) of ±4V will result in a mouse sensitivity (Y-Res) of 25mV of
each mouse step (MS) (25mV/MS,Y-Zoom=1). Using the Y-Zoom option the vertical sensitivity may be
increased by a factor of five (5mV/MS) or by a factor of twenty-five (1mV/MS) and will split the vertical
axis. The parameters will be put out within the output boxes named <Y-Fac> and <Y-Res> in the
parameter section at top of the main menu of the graphic editor.
3.2.3 Select Current Range - < I-Range >
The selected current range will be marked by a green square right to the selective button of the menu
list named 'I-Range'. To choose a different resolution activate the corresponding button and confirm
the selection. <current range> must be used to define the output range of a galvanostatic element and
does not affect the resolution of the measured current.
The current range must be selected in accordance to the used hardware. Using the internal
potentiostat the output range may be any one between ±400nA and ±4A. Note that the upper limit will
be given by the maximum possible output current of the used potentiostat (±1A, ±2A or ±3A ). By use
of HIZ-probe amplifiers the output range may be extended down to a ±4nA-Range. The ±40A and
±400A options have been prepared for use with the electronic loads EL100/EL101/EL300 only.
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Each vertical page will consist of ±160 steps in resolution being symmetrical to the middle of the page.
The current resolution is defined by the interdependent parameters 'Y-Fac' and 'Y-Res'. Selecting an IRange (Y-Fac) of dI= ±40mA will result in a mouse sensitivity (Y-Res) of 250uA of each mouse step
(MS) (250uA/MS,Y-Zoom=1). Using the Y-Zoom-option the ver tical sensitivity may be increased by a
factor of five (50uA/ms) or by a factor of twenty-five (10uA/ms) and will split the vertical axis. The
parameters will be put out within the output boxes named 'Y-Fac' and 'Y-Res' in the parameter section
at top of the main menu of the graphic editor.
3.2.4 Select Vertical Resolution - < Y-Zoom >
The vertical axis of potential and current will be scaled in ±160 steps of graphical resolution. Each
increment or decrement will correspond to one mouse step. Using a vertical resolution Yres=1 will
result in a mouse sensitivity of Rangeset/160 per mouse step and the total input range will be displayed
within one screen.
Selecting a higher Y-Zoom-value will increase both, the mouse sensitivity and the number of vertical
pages. E.g.:
Mode: Potentiostat
Y-Zoom
Sense
1
25mV/ms
5
5mV/ms
25
1mV/ms
E-Range: 4V
Pages & Range
Offset E0
1
4.00V
0V
9
0.80V
-ix0.80V,...,0V,...,+ix0.80V
49
0.16V
-ix0.16V,...,0V,...,+ix0.16V
i= 4
i=24
After startup the Y-Zoom-factor will be set equal to one by default. To choose a higher/lower Yresolution activate the corresponding button of the Y-Zoom menu list and confirm your selection.
When using a high resolution mode (Yzoom=5 or Yzoom=25) the different pages will be accessible by
and . The position of the actual page within the full input range will be
use of the buttons
displayed within the scale right to the input window.
3.3 Setup Potentiostat
The potentiostat may be set up differently for each element of a PVI-control
sequence. Note: changing the mode of operation does not affect the actual state
of the potentiostat but will define the mode of operation of the next element(s) to
be put in. During the execution the potentiostat's mode of operation will be set
according to the individual preset(s).
3.3.1 Select Active/Inactive Potentiostat - < POTstate >
<POTstate> works like a toggle switch and offers two states
'ON'
active state to switch on potentiostat/galvanostat
Select 'ON' to put out a control potential or to put out a control current.
'OFF'
passive state to switch off potentiostat/galvanostat
Select 'OFF' to switch off the potentiostat and record the rest potential.
3.3.2 Select Operating Mode of Potentiostat - < POTmode >
<POTmode> works like a toggle switch and offers two states
'POT'
potentiostatic mode
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Select potentiostatic mode 'POT' and switch 'ON' the potentiostat to perform e.g.
voltammograms, potentiostatic polarization or potentiostatic pulse sequences.
Select potentiostatic mode 'POT' and switch 'OFF' the potentiostat to record the rest potential.
'GAL'
galvanostatic mode
Select galvanostatic mode 'GAL' and switch 'ON' the potentiostat to execute constant current
experiments like charging at a fixed current.
3.3.3 Select Autoshunt or Fixshunt Mode - < I-Range >
This toggle switch will shift between
'LIN'
'LOG'
linear measurement of current (solid laboratory resistor)
logarithmic measurement of current (auto-shunt)
depending on the program version.
3.3.4 Select (E,I,t)-Data Acquisition - < DataAcqu >
Data acquisition may be selected differently for each PVI element. The memory being available for
data acquisition may thus be splitted to different regions of interest by the user, e.g. slow ramps will be
monitored with a low acquisition rate and fast pulses will be measured with a high sampling frequency.
Further on elements may be put in where no data will be measured at all.
To select a certain sampling frequency activate <DataAcqu> and select the corresponding button or
switch off the data acquisition if desired. The set sampling frequency will be marked by a green filled
rectangle right to the corresponding button.
3.4 Editing a PVI Control Sequence
3.4.1 Add Corner Point(s) - < APPEND >
Clicking this menu point allows either to enter a new curve or to append further points to an existing
curve. The program's input mode is active as soon as APPEND has been selected. A new ramp can
be defined when starting at zero or at the element entered last. During editing, the following
parameters are displayed in the parameter field:
a)
b)
c)
the absolute default data tabs, Uabs or Iabs at the current cursor position,
the relative changes of these parameters in relation to the PVI element entered last,
the slew rate of voltage or current, which is shown as a third parameter, results from the
relative values.
The new PVI element can be entered by confirming when the new terminating point has been
reached. Several aspects may lead to the input of a new element. Corner points may already be
defined or the desired slew rate can be realized for a certain time span tsoll.
The input of the required values can comprise times or potentials which are outside the window
currently displayed. As soon as the mouse is moved over the left, right, upper or lower limit of the
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window, a shift to a new window is effected automatically. During the input of a line element the
mouse sensitivity may be altered by use of the toggle function (right mouse key).
3.4.2 Numerical Input - < ? >
Corner points may be defined by a direct input routine too. To put in or to add a new corner point
activate the <append>-function and use the <?>-key to call the input routine.
The input box offers the input of the following parameters
-
Ea/Ia
dt
Ee/Ie
S
the starting potential/current
the runtime of the element
the ending potential/current
the potential/current slope
A new element will be defined by use of three parameters
-
Ea,
Ea,
Ea,
dt,
dt,
Ee
Ee,
slope
slope
The remaining parameter must be declared unused by clearing the corresponding input line with the
<crol>-key (clear rest of line). Otherwise the input will be over determined and the input routine will
prompt an error message.
The starting potential or the starting current will be put in absolute units of Volts or Amperes. As
starting point the input routine will suggest the last potential/current having been put in. The runtime of
the new element must be put in in units of seconds. Finally the ending potential or current will be
defined. This input may be an absolute value
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: 2V(abs)
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En=2V
or a step relative to the last corner point's potential or current
Ee/V
: 1V(rel)
En=En-1+1V
Another way to put in a new ramp is to define its runtime and potential slope or current slope.
3.4.3 Change Mode of Operation - < Change Mode >
The operating mode of individual PVI elements can be changed additionally after the input. Set the
desired operating mode and change the relevant elements.
To select an element move the crosshair close to the line element to be changed and confirm the
selection. The program then will search for elements which are within the region of the crosshair in a
defined capture range. After an element has been identified it will be included into the editing mode
and will be marked by flashing the corresponding line. The updated operating parameters are again
displayed online in the information field. Use the ENTER function to change the mode or use the
ESCAPE function to leave that element unchanged.
The ESCAPE function finally is used to leave the editing mode.
3.4.4 Edit Corner Point(s) - < EDIT >
After the input of the control elements via <append> or after an existing control curve has been loaded
PVI offers the possibility to edit the corner points. Thus fine corrections of a control curve may be
done.
3.4.4.1 Moving Corner Point(s)
To edit a corner point move the crosshair close to the corner point to be changed and confirm the
selection by use of the ENTER function. The program searches for corner points which are within the
region of the cross hair in a defined capture range. After a corner point has been identified it will be
marked by the flashing cursor.
Confirming this measuring point includes it in the editing mode. As described under <append> the
measuring point can now be entered newly. The updated operating parameters are again displayed
online in the information field. The parameter time can only be varied in a region which is stretched out
by means of Pm-1 and Pm+1 in order to avoid erroneous input.
The ESCAPE function is used to leave the editing mode.
3.4.4.2 Insert New Intermediate Point(s)
To insert a new corner point between two existing PVI elements, move the crosshair close to the line
which is localized by these points. When the computer has identified one of the lines within its capture
range, a new corner point is defined and can be edited as described above.
3.4.4.3 Possible Error With <EDIT>
a)
b)
The crosshair has not been moved close enough to the element sought after. In this case, the
computer draws the attention to the user with the help of an audible signal.
Too many points or lines have been identified. In this case, an error message is given and one
is asked to select a finer time resolution or to specify the point which should be edited newly.
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3.4.5 Delete Existing Corner Point(s) - < DELETE >
This function is used to delete corner points of an existing PVI list. To delete a corner point move the
crosshair close to that corner point and confirm the selection by use of the ENTER function. The
program searches for corner points which are within the region of the crosshair in a defined capture
range. After a corner point has been identified it will be marked by the flashing cursor. The selected
point is deleted by confirming with the ENTER function. To cancel the delete function use the
ESCAPE function. Errors are recognized and displayed as being described above.
3.5 Clear PVI Control Memory - < CLEAR C-DATA >
This option will be used to clear the memory of the control data section. An existing curve
will be cleared and the control curve editor will be reset to the initial settings. Erroneous
use will be prevented by an input box
Confirm to clear all control data or escape to leave all inputs unchanged.
3.6 Setup Data Acquisition (Optional ANDI-Amplifier Modules)
In addition to the potentiostat which will deliver the measure data of potential E and current I
supplementary amplifier modules may be installed. These modules will list additional parameters of
the experiment, like temperature, pressure, pH-value, viscosity, speed of rotation, etc.
The data acquisition modules will be put into the system and the single input channel's parameter set
will be defined via the function
<Signal Acq.>
and it's sub-function <Signal Acquisition Setup>
.
The signal acquisition setup may be called nearly from every measuring program of the Zennium. The
input channels can be recalibrated and the sequence of active channels can be altered with respect to
actual requirements. After return all parameters of the data acquisition setup will be passed to the
calling program.
3.6.1 Select Active Channels
The data acquisition setup can handle 32 input channels of additional acquisition modules. Data
acquisition of analog channels with PVI, however, is restricted to a maximum of 10 active analog
channels. Thus the desired channels must be within the ten first channels of the data acquisition
setup. By an interactive exchange PVI will obtain the calibration parameters and the addresses of
those channels. To check and setup the data acquisition activate the function <Setup Data
Acquisition> by use of the button.
Within the editor's page a submenu will pop up and offer selection of active channels. Activate all
desired channels by use of the corresponding <Chan x> button. An active channel will be marked by a
green square right to the button, an inactive channel will be marked red.
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3.6.2 Activate Data Acquisition
In contrast to the measurement of the PVI data triplets <E,I,t>, which will be measured with respect to
the setting of the corresponding PVI element, analog data acquisition will run thru the whole
measurement if data acquisition will be active. To switch off or on the data acquisition at all, use the
button <ON> or <OFF> at the top left of the input list. Activated data acquisition will be marked by a
green square and offer to switch <OFF> while inactive data acquisition will be marked red and offer to
switch <ON> data acquisition.
3.6.3 Define Sampling Frequency
Due to the structure of the operational system's measuring macro, all additional data channels must
be sampled with one fixed sampling frequency. The maximum sampling frequency itself will be
restricted by the memory being offered by the system. Variation of the free memory of <APts> is
offered by splitting the PVI memory via the <MEMORY> menu.
To choose a certain sampling frequency activate the button named <sampling frequency>. A further
submenu will pop up and offer a set of frequencies being split in decades. Each decade will be split in
units of 1,2 and 5. The selected sampling frequency will be marked by a green square right to the
corresponding button.
To use all memory being offered for additional data acquisition select the additional option <fit
maximum frequency to memory>. The maximum sampling frequency will consequently be calculated
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with respect to the settings of <APts> -memory and the number of acquisition channels being
activated.
3.7 Modify I/O’s
To registrade additional magnitudes of an electrochemical experiment the measuring programs of the
THALES software can manage up to 32 supplementary analog inputs. The measured parameters will
be amplified and normalized by the ANDI amplifier modules offered by ZAHNER. The actually offered
modules are listed in the table below. Considering electrochemical investigations the TEMP/U module
has become a standard. This module has two temperature channels for Ni/CrNi-thermocouples and
two voltage inputs.
module' amplifier card
module#
1
2
3
4
5
6
7
8
9
10
11
amplifier card
FE40
4ch E / diff. inputs
LMV
1ch I / program. charge amp.
PAM
1ch E / program. E-amp.
TEMP
4ch Temp / iso-amp Ni/CrNi
TEMP/U
2ch Temp / 2ch E
RTD
4ch Temp / iso-amp PT100
DMS
4ch iso-amp for strain gauge sensors
UMUX
8ch diff / 16ch sing E-amp
ISO_IN
4ch E / iso-amp
FILTER
1ch filter amp
FE42
4ch E / diff. inputs, var. gain
The management of additional analog inputs will be done by the common routines of the <Data
Acquisition> -section. This program will be reached either from the main menu of the THALES
software or by special entries from the measuring programs. The active number of analog channels
may differ from program to program.
PVI
THALES main
EIS programm
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- 20 -
3.7.1 Signal Acquisition Setup
To define or to modify an analog input channel activate the button <edit input>. Then move to either
the left or to the right table. Each table can store the parameters of 16 input channels.
Select the desired channel by moving the mouse arrow into the corresponding line. An activated input
will be marked by a lit bar. To define/modify that channel's parameters call the editor by using the
<ENTER> -function. Consequently an input function will offer the input of 15 parameters to calibrate
and describe that input channel.
An analog input channel must be defined by input of the following parameters
- hardware address
channel #
module #
:
:
digital address
type of amplifier
- descriptor and unit of measured magnitude
magnitude
unit
max. display
:
:
:
physical/chemical magnitude
unit to be put out
maximum range of display
- polynomial of calibration
The digital data being read from the ADC will be converted to the physical value of the measured
magnitude by use of a polynomial
n PO
M
C0
C1 ADC
n 2
C n ADC
n
e.g. polynomial to calculate the temperature T from the measured potential of a Cr/NiCr thermo couple
(TEMP/U-module)
PO
C0
C1
C2
C3
C4
C5
polynomial order
offset #0
gain #1
coefficient #2
coefficient #3
coefficient #4
coefficient #5
:
:
:
:
:
:
:
7
3.97085242e-3
0.101499149
-6.87552777e-6
3.86680650e-9
-1.64198803e-12
1.30383059e-15
PVI
C6
C7
C8
coefficient #6
coefficient #7
coefficient #8
:
:
:
- 21 -
-5.10712536e-19
5.76442358e-23
0
To deactivate an analog input channel simply put in a zero as input channel number. Before
confirmation check all inputs. To correct single parameters use the <CU> - <CD> -keys and move to
the corresponding input line. To exit the parameter definition function confirm at the last input or exit
by use of the <END> - or <ENDE> -key.
3.7.2 Save & Load Calibration Factors
If an supplementary amplifier will be delivered with the system, the corresponding input channels will
be defined by the manufacturer. Otherwise the calibration table will be delivered with the module and
must be installed by use of the functions being described above.
The calibration factors will be saved by using the saving option of the <global measurement preset>.
Saving the complete parameter set will result in an automatic reinstallation after the next startup of the
system.
3.7.3 Check Active Inputs
The correct operation of the activated channels may be checked. Therefore the <signal acquisition>
page must be entered.
Up to a maximum of 10 activated channels will be displayed by the use of 'digital instruments' as
shown above. By alternation of the input signal an control of the output signal all active channels can
be checked.
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- 22 -
4. Saving & Loading of Control Data
The defined set of control data may be stored as a Control Data file or as a Sequence.
Both types of control data may be loaded directly and offer an immediate start of the
experiment. The functions which will be used to save and load control data are the same
as being described in other parts of the THALES-manual.
The buttons <Sequences> and <Control Data> lead to a submenu which will offer
disc-i/o-operations. The following menu-points will be offered:
4.1 Load File - < OPEN >
The selected control data file will be loaded to the editor.
4.2 Save File - < SAVE >
Saves control actual control data to the selected subdirectory.
4.3 Creating Repetitive Curves - < SEQUENCES >
Both kinds of data - control data and sequences - have the same internal format. Loading a control
curve will erase the control curve being stored in the memory of the PVI editor. For the use of
sequences, however, a special handler will be offered when sequences will be loaded to the editor:
sequences will be appended to the actual control curve.
A sequence describes a short(er) set of PVI-elements, e.g. a polarization at constant potential being
followed by a short pulse. Sequences may be sets of potentiostatic or galvanostatic elements. By use
of the <sequencer> those sequences may be arranged to a new curve of control data. Loading a
sequence an input box will prompt, asking how often the selected sequence shall be appended to the
existing control curve.
Before a sequence will be loaded the system will check the editor's memory and will determine the
maximum number that the selected sequence can be appended to the actual control curve.
By the introduction of the sequence handler PVI offers a nearly indefinite degree of freedom to create
control curves with respect to special demands.
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5. System Parameter
Within the installed measuring programs of the THALES system usually all settings of the
potentiostat will be done by the software. To offer selective control of the hardware a set of
system parameters has been provided.
5.1 Reentry to EIS-Program
Some types of electrochemical investigations demand an EIS measurement directly after the probe
has been prepared. After the EIS-spectrum a polarization shall follow and finally the sequences shall
be terminated with a second EIS measurement. PVI therefore offers the automatic reentry to EIS. The
experiment will be started with an impedance spectrum. Then the user changes to PVI and the DCsequence will be started. After the DC treatment has been finished, PVI will pass the last actual DCpotential of the potentiostat to the EIS program and a second impedance spectrum will be started
automatically.
5.2 Shunt Resistor and Current Range & Limit
Considering potentiostatic elements PVI will work with a fixed shunt resistor for the whole sequence.
This shunt will be selected by the user either by determination or by estimation of the maximum DC
current to flow. The following table may help to choose an adequate shunt resistor with respect to the
expected DC-current that may flow.
current / A
10
5
300 m
110 m
40 m
4m
400 u
40 u
4u
400 n
40 n
4n
shunt / Ohm
10 m
100 m
1
10
100
1k
10 k
100 k
1M
10 M
100 M
1G
note
IM6 only
Zennium/IM6
Zennium /IM6
Zennium /IM6
Zennium /IM6
Zennium /IM6
Zennium /IM6
Zennium /IM6
Zennium /IM6
Zennium /IM6
HIZ probe only
HIZ probe only
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- 24 -
Selection of a specific current range will determine the used shunt resistor. The selection, however,
will work semiautomatic. In the higher current ranges between 40mA and the maximum current lmax a
fine splitting will be done automatically with respect to the maximum power consumption of the
selected shunt.
The potentiostat itself will be protected by a current limiting circuit with respect to the selected shunt
resistor. The potentiostat otherwise will get no information about the allowed current through an
electrochemical system. Thus the selection of a current range will define current limits that will be
defined by the user and consequently will be controlled by the software. Current violations will cause
an interrupt of a running PVI-sequence and the potentiostat will be disconnected from the investigated
system.
5.3 Current Limit - < LATENCY TIME >
Limiting the dynamic range of the DC-current offers protection of the system being connected to the
potentiostat. Short current spikes caused by switching devices via 'electro smog', however, may cause
an unwanted interrupt of the running PVI sequence. The parameter <latency time> has been prepared
for selective control of current violations.
ILimit
enableinterrupt
ILimit
Potentiostat
switched OFF
t
Trigger
t+t latency
CurrentI/arb.units
CurrentI/arb.units
PVI will continue
stopPVI
CurrentI/arb.units
ILimit
enableinterrupt
CurrentI/arb.units
stopPVI
PVI interrupted
ILimit
t
Trigger
t+t latency
5.3.1 Defining an Active Control Window t>0
A current violation will trigger a time window. If the current will return to the allowed magnitude within
the defined latency time (=window width) the measurement will continue. If the current will stay outside
of the defined range the PVI sequence will be interrupted.
5.3.2 Selection of Immediate Interrupt t=0
Setting the current violation latency time equal zero will cause an immediate interrupt of the running
sequences in case of current violations.
5.3.3 Switching Off Software Current Control t<0
Setting the latency time to a negative value will disable software current limiting at all.
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- 25 -
5.4 Settling Time
IMx potentiostats have been designed to work up to a maximum frequency of some MHz. This short
response times may cause oscillation if the potentiostat will change its mode of operation or the
current range will be switched. Especially switching the current range in galvanostatic experiments
may cause unwanted spikes in the current signal. Considering DC-experiments the bandwidth of the
potentiostat may be limited by a switch able low-pass in the potentiostat's feedback loop.
The <settling time> may be set to the requirements of the planned experiment. <settling time> offers
the following limits:
settling time
100 ns
1 us
10 us
50 us
200 us
edge frequency
10 MHz
1MHz
100 kHz
20 kHz
5 kHz
Considering the internal sampling rate of the PVI driver of 10kHz, bandwidth limiting down to 50us will
cause no loss of information.
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6. Execute – Select Online Display and Start
Measurement
The actual measurement is started here. The input data are converted into internal control
data of the machine. The conversion is indicated on the screen in a so-called 'busy' box. A
time system guarantees the synchronous sequence of the actual measuring program in the
background and makes an online representation of the latest potential and current values
possible by means of a specific data exchange between the driver program and the PVI. A
new graphic is set up after a defined runtime. The measuring range is displayed quasicontinuous in the data window in a reasonable resolution.
Both the mouse and the keyboard are permanently scanned during the measurement. If the ESCAPEfunction will be activated, the measurement will be interrupted at the latest position. The data triplets
<t,U,I> measured by then remain in the storage medium and can thus be evaluated. With that, it is
possible to intervene at any position of the measurement and change the system's parameters.
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- 27 -
6.1 Selection of Online Display - < SELECT DISPLAY >
PVI offers different displays for the online display of the measured data. The single
scope mode will preferably be used if only potential- and current data of the PVI
sequence shall be displayed online. The double scopes and the triple scope have
been provided for the display of additionally measured analog data.
To select a online display activate the button named <select display> and a selective menu will pop
up. Select the desired display and leave the menu by use of the ESCAPE-function.
The displays run along the same time axis being plotted at the bottom of the window. At the top
numerical displays have been installed to put out the measured data of all activated channels in
numbers. The data will be plotted along a floating time axis. After a defined duration a refresh of the
window will occur and the time axis of the next interval will be plotted. In case of an overflow a clipping
window will be activated and the displayed data will be limited to the upper or lower limit of the
corresponding axis. For each scale individual scaling and color selection have been prepared.
6.1.1 'Single'-Scope Display
The single scope display offers one window with two y-scales, one at the left and the other at the right
of the window. Both scales may be defined individually.
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- 28 -
6.1.2 'Double1'-Scope Display
The 'double1'-scope display offers two 'scopes' of identical height. Each scope offers two y-scales,
one at left and the other at the right of the window. All scales may be defined individually.
6.1.3 'Double2'-Scope Display
The 'double2'-scope display offers two 'scopes' of different height. The data of most interest may be
displayed with a higher resolution within the lower window. Additional monitoring data may be
displayed in the upper window. Each scope offers two y-scales, one at left and the other at the right of
the window. All scales may be defined individually.
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- 29 -
6.1.4 'Triple'-Scope Display
The 'triple'-scope display offers three 'scopes' of identical height. Each scope offers two y-scales, one
at left and the other at the right of the window. All scales may be defined individually.
6.2 Select Input of an Axis - < SELINP >
Each scale may be assigned to an analog input channel. Input channels are the internal data potential
and current or additional analog input signals being measured by supplementary amplifier modules.
To assign an input signal to an axis activate the corresponding button <SelInp> of that axis. A
selective menu will offer that analog channels which had been activated for the next measurement. All
active inputs will be represented by a button storing the corresponding channels descriptor. The active
channel will be marked by a green square right to the button. To select another analog channel
activate that channels button. To switch off an axis select option <SCALE OFF> at the top of the
selective window.
To distinguish graphs being plotted within one window the different channels can be plotted with
different colors. To select a certain color activate that colors button. The selected color will be marked
by a green square right of the button. The selection of a certain color will influence both the color of
the graph and the color of the axis being plotted.
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- 30 -
6.3 Scaling of Data - < SELGAIN >
To select certain regions of interest different scaling of the activated axis has been provided. Each
scale may be defined individually. The limes of the display must not correspond with the maximum
range of the corresponding input channel. In case of zooming clipping of the corresponding window
will be activated.
To define an axis' scaling parameters activate the button <SelGain> of that axis. A selective menu will
offer the setting of three gain switches <Fine-Gain>, <Gain> and <Range>. Via <Range> an
engineering unit will be selected. <Gain> will select a certain decade of that unit and is scaled in units
of 1,2 and 5. <FineGain> finally offers a zooming of ±4, ±2 or ±1.
The parameter offset will determine the position of the zero line. The offset must be put in after the
input function has been activated by use of the <Offset> button.
Example:
To select a display between -10mA and +30mA choose
Range:
1m
Gain:
20
Fine Gain:
1
Offset:
10m
6.4 Select Window Refresh Time - < SELTIME >
A new graphic is set up after a defined time has run down. This option offers
splitting of the whole runtime into smaller intervals of time. By the use of splitting
a better resolution of the displayed data may be obtained. The refresh time may
selected between 10sek and 30hours, depending on runtime and desired resolution of the online
display. To change the refresh time activate the button <SelTime> below the x-axis and select an
interval.
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- 31 -
6.5 Start Measurement - < START MEASUREMENT >
To start the next measurement activate the button <Start Measurement>. The input
data will be converted into internal control data of the machine and graphical
display data will be calculated. Both processes will be indicated by a busy box. Finally the <Start
Measurement> - button will change to a <Stop Measurement> - button and execution will be started.
6.6 Stop Measurement - < STOP MEASUREMENT >
To interrupt a running experiment use either the ESCAPE-function or activate the STOP-button at the
top right of the display window.
After a measurement has run out or has been interrupted the data measured by
then remain in the storage medium and can thus be evaluated. With that, it is
possible to intervene at any position of the measurement to change the default data or Imax. An
immediate restart will be possible as the control data will be stored and accessible in memory.
PVI
- 32 -
7. Evaluation – Visual Display of the Data
The software version of EVALUATION on hand contains subprograms for the graphic representation
of data. After the selection, the measuring data, which are available in an internal reporting format by
then, are transformed in real number triplets. This is required because the data are saved in a format
(4 byte integer) other than the one applied for reporting (8 byte real). During the data conversion, this
is indicated by an alert box.
After the conversion has been finished, the program changes to another graphics page with a new set
of buttons. The basic setup of the graphic shows the current and the voltage channel as two separate
graphics over the acquired time range. Two cursors are strobed additionally, with CURSOR 1 being
the starting point and CURSOR 2 being the terminating point. The latest cursor settings are again
displayed in the upper data field.
The following subprograms have been provided to cut out a curve by reverse clipping or to enlarge a
window.
7.1 Select Active Channels - < E Chann > , < I Chann >
These toggle functions allow to activate and deactivate the two measuring
channels for the graphic presentation. If both channels are active, the re
presentation will be done in two frames of equivalent height. The overall height of the
screen will be used for graphic operations if only one channel has been activated.
PVI
- 33 -
7.2 Select Scale Type - < E Scale > , < I Scale >
Both data channels can either be printed out linearly or logarithmically. One can choose
between those ways of presentation by using the toggle functions I scale and U scale.
In the logarithmic representation, negative Y-values have another color than the values of the positive
Y-range.
7.3 Redraw Graphs - < E Redraw > , < I Redraw >
Using one of these functions results in rebuilding the graphic. However, the execution will
be denied if the relevant data channel has been deactivated
7.4 Setting of Cursors - < Cursor1 > , < Cursor2 >
Cursor 1 and Cursor 2 are used to reset the cursors within the data range. The mouse
arrow disappears and is connected to two cursor segments (vertical and horizontal axis).
The arising crosshair can be scrolled to the left or to the right with the mouse, but the cursor follows
single data points. The contents of the single measuring points are assigned to the relevant cursor and
are displayed to the right of the upper screen region. Pressing RETURN/ENTER changes the position
of the cursor. The ESCAPE function is used to exit the Cursor functions. The cursor returns to its
original position.
7.5 Magnification of Window - < Zoom >
Clicking this function prompts the program to adopt the latest cursor positions as new
extrema of the time axis and to present spread measuring data in a redefined time window.
Renewed setting of the cursor and sub- sequent confirmation of the Zoom function allows further
magnifications.
7.6 Display Whole Measurement - < Total >
It will be possible to restore the data of the whole time field by this function if the measuring
data field has been zoomed.
7.7 X/Y-Presentation of the Measuring Data - < XY-plot >
It is often advisable to use XY-plots in order to recognize the inter relations between the
measurands time, potential and current. In this subprogram, the user is able to apply one measurand
(t,U,I) to another measurand (t,U,I). Linear as well as logarithmic shifts are possible for both scales.
That is why logarithmic I(t) plots and double logarithmic I(U) plots can be used like any other
combinations.
As in the linear presentation modes, the user is free to define the output parameters and their way of
representation.
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- 34 -
7.8 Select X-Y-Channel - < X Chann > , < Y Chann >
The corresponding data channel can be selected via these functions.
7.9 Select X-Y-Scales - < X Scale > , < Y Scale >
The corresponding scale can be selected here. The content of the other menu points,
regarding the X/Y-presentation, is equivalent to the one of the linear representation modes.
7.10 Redraw X-Y-Diagram - < XY Redraw >
The X-Y-graphic will be redrawn if any of the display parameters ( X-Chann, Y-Chann, XScale or Y-Scale) has been changed or the cursors have been set to another position within the data.
7.11 Return to Time-Representation - < EI-T-Plot >
The display will return to the E(t)- and I(t)-representation of the data. The switch will only
act if X-Y-representation had been activated.
7.12 Calculating Integrals ∫E(t)dt / ∫I(t)dt
This function will work in the E-I-representation of the PVI-data only. By use of the cursors a time
interval will be defined and finally the pro gram will calculate the desired integral. The result of the
calculation will be put out at the top of the display. The following data will be listed:
∫abs
∫pos
∫neg
∫net
mathematical overall integration (area under curve)
positive contribution of integral
negative contribution of integral
netto integral (net=pos-neg), e.g. effective charge transfer
Start
End
Base
start of time interval
end of time interval
baseline y-coordinate at start and end of time interval
By use of the additional buttons <editor> or <printer> the result of the integration may either be passed
to the text editor of the system or may be printed out on the system's printer.
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- 35 -
7.13 Integration with Baseline
Each integral may be calculated with respect to the standard y=0-line or by use of a baseline to obtain
e.g. 'netto'-charges of current-peaks. Before an integration will be started an input box will prompt and
ask if a baseline shall be defined.
Selecting the option 'with baseline' the baseline must be defined. The x-coordinates will be the left and
the right limit of the time window being defined by the cursors. The y-coordinates of the baseline will
be put in by use of the mouse. Therefore two markers may be moved, one on the left time axis t1 and
the other on the right time axis t2. Activation and sliding of the markers will be done by consequently
use of the <ENTER>-function and of the <ESCAPE>-function. The sequence of baseline definition will
schematically be shown in the graphic below.
left mark
flashing
ESCAPE
ENTER
ESCAPE
left mark
sliding
ENTER
ESCAPE
right mark
flashing
ENTER
ESCAPE
right mark
sliding
ENTER
baseline
defined
INTEGRATION
7.14 Printer Hardcopy - < HARDCOPY >
The displayed diagram may be put out via the line printer hardcopy function. After the
selection of HARDCOPY, an additional menu appears on the display unit. Both the
parameters for the screen copy to be drawn up and the active output device can be entered and
clicked here. After confirming the operation, a part of the screen is inked. The reason for this is that
the majority of devices in use are black-and-white printers, which will only produce a copy if all the
current data and parameters have been resolved properly. Before output a menu will offer the setting
of the print parameters. Thus the size of the hardcopy and its orientation can be selected to certain
PVI
- 36 -
requirements. The printer type as the printer's IEEE interface number may be changed for different
devices. Finally the output may be started and a form feed may be enforced.
7.15 Create ASCII-Data List - < DATA LIST >
To transfer the measured <E,I,t>-data to other computer systems, the actual data may be
converted to an ASCII-data-list. This list may be put out at a printer, may be transferred to
the text-editor of the UTIL-software or may directly be saved to a MS-DOS compatible device.
For export of ASCII-data PVI offers an additional menu. This menu is divided into three sections:
<PVI-data>, <ACQ-data> and <parameters>. If no ACQ-data had been measured the middle section
dealing with ACQ-data will be covered by a light red bar indicating that no transfer of ACQ-data is
possible.
The ASCII-list of PVI-data and of ACQ-data must be created separately as there is no common time
base for both types of data. At the moment no interpolation to the contrary time base has been
provided.
7.15.1 Listing PVI (E,I,t)-Data
Four columns of data may be listed
- index
- time
- potential
- current
number of order of measured point
measure time
measured potential
measured current
Each of the columns may be selected by a separate toggle-switch. An
activated column will be marked by a small green 'LED' right to the
corresponding button. As all data will be passed via a common basic stack of
restricted length only a certain number of rows can be passed to e.g. the
texteditor. The stack size is given at the bottom right of the menu and the
calculated maximum number of rows to be passed will be given in 'max
rows'. The amount of data and the region of interest will be indicated by use
of indices 'index'.
PVI
- Data
- Start
- Length
- End
- Step
- 37 -
dimension of data field
starting index of list
length of list
ending index of list
step width of output
Considering the amount of data and the data density a selective output will be possible by use of
these parameters. After all settings have been done the output will be started by use of the button
<create PVI-list> at the top of the menu.
7.15.2 Listing ACQ-Data
Six columns have been provided to put ACQ-data
- index
- time
- Chann0
- Chann1
- Chann2
- Chann3
number of order of measured point
measure time
analog CH0
the intermediate analog channels
analog CH1
CHx will be assigned to the first
analog CH2
four of all activated channels
analog CH3
by the analog channels setup.
Each of the columns may be selected by a separate toggle-switch. An activated column will be marked
by a small green 'LED' right to the corresponding button. As all data will be passed via a common
basic stack of restricted length only a certain number of rows can be passed to e.g. the texteditor. The
stack size is given at the bottom right of the menu and the calculated maximum number of rows to be
passed will be given in 'max rows'. The amount of data and the region of interest will be indicated by
use of indices 'index'.
- Data
- Start
- Length
- End
- Step
dimension of data field
starting index of list
length of list
ending index of list
step width of output
Considering the amount of data and the data density a selective output will be possible by use of
these parameters. After all settings have been done the output will be started by use of the button
<create ACQ-list> at the top of the menu.
7.15.3 Control Parameters of ASCII-List Output
The most right section of the ASCII-list menu offers selective use of output parameter. Usually text
delimiters will be the <SPACE>-character. Use of import filters, which may demand special characters
to format a text, three control characters may be defined
- EOD End Of Data character
- EOL End Of Line character
- EOF End Of File character
To change a control character activate the corresponding button and put in the new
control character. In addition to the character itself, its ASCII-code and the
hexadecimal code will be indicated additionally.
A additional toggle switch offers selection if a block of header text containing
information about the measuring condition shall be put out too. Header output will be
indicated by a green 'LED' right to the <header> button.
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7.15.4 Output of ASCII-List
After the output of the ASCII-list has been activated a series of selective menus will guide to the final
list device.
The list device will be selected by a small menu, appearing after the listing has been started. An
example of an ASCII-data-list will be given in the appendix.
a)
b)
c)
The data list may directly be passed to a line printer. When selecting this option a menu will
offer the possibility to set the output parameters according to the addressed printer.
Sending a data list to the texteditor offers two modes of output, either by creating a new list or
by appending the data to an existing text.
By the direct to DOS option the data will be saved directly to a MS-DOS device. The default
data path of an ASCII-list to put be put out, data will be defined within 'setup' of the UTILprogram.
7.16 Saving & Loading of Measurement Data - < DiskOps M Data >
The functions which will be used to save and load measure data are the same as being
described in other parts of the THALES-manual. The button <DiskOps MData> will lead to
a submenu offering disc-i/o-operations. The following menu-points will be offered:
7.16.1 'load file' - < OPEN >
- The selected control data file will be loaded to the editor.
7.16.2 'save file' - < SAVE >
- Saves control actual control data to the selected subdirectory.
For more information kindly refer to other sections of the THALES-manual, where the disc-ops have
been described in detail.
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7.17 Evaluation of Other Time Data
Time data of the format (E,I,t) will be recorded by e.g. CV or IE. To display and evaluate cyclic
voltammogramms CV and stationary current potential curves IE two input functions have been
provided:
loads a cyclic voltammogram
loads a stationary current potentiyl curve
NOTE: Due to the different file structure of the measure data files of PVI, CV and IE these function
will work for the loading option only.
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