Juniorassist Brochure

Electrochemical measurementsmanaging softwareJunior Assist1ST ISSUE APRIL 2003Via San G.B de la Salle, 4 – 20132 MILANOTel +39-02-27203060, Fax +39-02-2564832email amel@amelsrl.com web www.amelsrl.comUNI EN ISO9002 9INDEX1- INTRO2- GENERAL FEATURES2.1 the experiment as a sequence of operations2.2 The block as the manager of the specific actions2.3 The software-firmware interactions in the 7000 series2.4 The data obtained2.5 Data plots and export3- GETTING STARTED3.1 System requirements3.2 Software installation3.3 Hardware connections3.4 How to run an experiment3.5 A simple test4- SCREENS AND MENUS4.1 The starting screen and toolbar4.2 The setup screen4.3 The block parameters’ structure4.4 Block’s common parts: the data acquisition set4.5 Block’s common parts: the termination set4.6 Block’s common parts: the hardware setup parameters5- PRIMITIVE FUNCTIONS5.1 CELL5.2 OCP5.3 STEP5.4 RAMP5.5 CYCLIC6- THE PLOT AREA6.1 axes cursor and zoom6.2 the real-time plot6.3 points’ decimation6.4 EIS experiments1- INTRODuring the past years there was a remarkable trend in the scientific instrumentationfor better, more proficient and more flexible experiments managing software.This is nothing more than the natural consequence of the increased capabilities foreach instrument in each field.Was easy, in the old days, turn the knob and look at the result, but today’scompetition in the science arena requires profound investigations, complex testingcycles and lighting fast data presentation to stay on the leading edge.The number of knobs to turn grow up to the point that nobody is able to rememberhow to do it, so the help coming from a well crafted software is mandatory.Electrochemistry is no exception, and started from very simple voltammetries toreach real-life simulations of battery usage with well described cycles and hundredsof measuring steps.At AMEL we decided to develop our own software starting from the long timedexperience on standard experiments and expanding to the most complicated cyclesthrough a structure that resembles a “toolbox” for experiments.For simple occurrences, a comprehensive experiment library will let you have atyour fingertip all the existing techniques, with full parameter controls.Then. If your need to deviate from the standard, a simple but powerful graphicaleditor opens to You a complete new world.We hope You will enjoy the use of such powerful instrument and we are waiting forYour feedback for even-better-performing products and software.2- GENERAL FEATURES2.1 the experiment as a sequence of operationsthe way Junior Assist manages the experiments is similar to the operations of asequencer: a complex test is then splitted in simple actions, that we call “blocks”,that are executed one after the other .The execution of the block is under the firmware control once the specific commandwas sent and the PC is then completely dedicated to gathering the data and to plotthem in real time.The controls on the data, like thresholds, and the conditional flow of the program isunder PC responsibility and the reaction time for the whole system is within amachine cycle i.e. 10 mSec.The program can then take full advantage of the PC flexibility and high levelprogramming, while time-sensitive parts are managed in real time by thepotentiostat microcontroller.2.2 The block as the manager of the specific actionsIn the potentiostat there are the “primitives” of the actions specified in the blocks, so, as an example, a scanning voltammetry is tightly managed from themicrocontroller that drives the data acquisition too, in such way that microsecondprecisions are allowed.In the “standard” 7000 system, the machine can enter in contact with the PC every10 mSec. And in that time it can send and receive commands (only in a special “fastmode” the 7000 is able to send a couple of data each 1 mSec).The block, and so the primitive function, has repetition capability for waveforms thatare intrinsically repetitive, like square waves or triangles, avoiding the delaysconnected to a reprogramming of the generator.The timing is then extremely precise and is not affected by the PC interrupt cycle.2.3 The software-firmware interactions in the 7000 seriesBy dividing the workload between the PC and the potentiostat, both systems arerunning at their best, with clean waveforms and always synchronised generation-acquisition phases.The PC, with the program, passes the working parameters to the potentiostat andthe potentiostat gives back the measures for the time requested: the unit is able todetect, within a measuring cycle, a command from the PC for modifying themeasure or for stopping it in the case some dangerous value should be reached.At the end of a block, the potentiostat returns a signal that enables the program toproceed forward in the experiment execution.Coded responses are used for detecting malfunctioning or hardware signals(triggers , etc.)2.4 The data obtainedThe 7000 series is able to measure two voltages , a current and a temperature, andit sends them back at 100 data sets per second.The PC program takes care of sample averaging or decimation before saving themand plot in real-time.The data set produced in the PC for each sample is including not only thosenumbers, but also some derived instantaneous quantities like power (VxI ) andresistance (V/I) , and some integral ones like energy (integral vs. time of power) andcharge (integral vs. time of the current).Due to the meaning of these values, both positive only and negative only integralsare calculated and stored; moreover the time of calculation is in any time both theone from the experiment’s start and from the block’s start.The record is then composed by the quantities that will allow to reconstruct, in asecond time, the complete data set out from them.2.6 Data plots and exportsThe data can be plot, both in real time and from rescued data, choosing which oneof the available quantities will stay on the X and on the Y axis.Linear and logarithmic scales are available for both.Due to the nature of the data collected (different sampling time for each block, otherparameters changes etc. ) the plot of all the collected data is just useful for a roughanalysis , while , by clicking on the desired block, an expanded plot of that blockalone can be obtained.The export facility , that translates a compact binary file in a CSV file ready for Excel, will follow the same rule, letting you save pieces of records, block by block ifdesired.In that case, all the direct, derived and integral quantities are reconstructed andplaced on the record.3- GETTING STARTED3.1 System requirementsThe software was developed under Windows environment , with compatibility withthe following operating Systems:- Win 98 s.e- Millenium- Windows 2000- Windows NT- Windows XPDue to the high speed serial communication the minimum system requirements arethe following:- Pentium III 400 MHz ( AMD systems of similar performance suitable)- 64 Mb RAM (128 Mb recommended)- 50 Mb free disk space (beware on long runs, 100 Mb better)- 1 RS-232 serial port available (an USB port with RS-232 adapter suitable)- CD-ROM- VGA with 800 x 600 min. resolution- Mouse or other pointing device3.2 Software installationThe software is supplied on a CD-rom :- insert the CD in the CD-rom reader- if you have the AUTORUN feature available the program will install itself: in thatcase follow the instructions on the screen- if you do not have the AUTORUN feature set , opens the CD drive directory andrun the INSTALL program- In the early version of the program, in case of upgrades, or for some specialneeds, the INSTALL PROGRAM will not be in the parent directory of the CD.In that case, copy the Directory JUNIOR ASSIST in your fixed disk , and thenmake a link to the JASSIST.exe program on your desktop by dragging it .NOTE: the program does not carry with it any DLL set or other parts to be installed:uninstall the program is then carried out by deleting the files in the directory.3.3 Hardware connectionThe only connection due for working with the program is the RS-232 from the PC tothe 7000-series device.The system is refurbished with a 9-pin serial cable or with an USB cable dependingon what is the option mounted: in both cases the software recognise the availableconnections and ask for the one to use: in the case of USB the program recognisethe attached unit and settles automatically for it.In the case a 25-pin serial port is available, any commercial adapter between 25-FEMALE to 9-MALE can work (note the sex of the adapter: some recent PCsdoes not have the RS-232 port but the printer port alone, that can be recognised jutbecause has an opposite sex, i.e. FEMALE on the PC)In both cases, galvanic insulation is placed between the PC and the digital groundof the 7000-series unit, so , no ground loop can come from that.3.4 How to run an experimentIn the following paragraphs we will show all the different parts of the experiment andhow to program them: here is explained the simple sequence needed to run anexperiment:- Launch the program- enter in the editor screen through the “NEW” button or command.- load or edit a new experiment- once the experiment is loaded or composed exit the editor’s screen through thebutton- now run the experiment (that will appear a s a flow chart in the side bar)using the start and stop buttons: In the real time graph area one can select the twoaxes needed to plot the dataremember to save the acquired data at the end of the run3.5 A simple testThe program comes with some libraries of ready-to-use experiments: just pick the“test” one and run it as shown previously: if the system is properly set the softwarewill start to show real-time data of no significance (it depends what is connected tothe potentiostat).If any communication problem will arise, a message box will inform You about themistake (no connection, no answer are the two possibilities).IN ANY CASE RUN THIS TEST WITHOUT A REAL ELECTROCHEMICAL CELL:IF YOU LIKE TO SEE SOME DATA IN A STRAIGHT LINE A 1 K OHM LOAD ON A2-WIRE CONNECTION TO THE POTENTIOSTAT IS ALWAYS SAFE TO RUN.4- SCREENS AND MENUS4.1 the starting screen and toolbarAt the launch, the first screen shown is as following:this structure of screen is common to all AMEL software and allows the user to have all theneeded data under control.On the top bar the main functions are available as commands and as buttons:- New : enters in the edit mode for the experiment- Open : allows the access to previously taken data- Save : save the current data- Start & Stop buttons for starting the experimentSame functions are found in the menus under File and Experiment.The area in the top left zone is showing the experiment flow, when one is loaded, on thebottom the darker window will report the actual status of the experiment and the latestmeasured value, while the large, squared area on the right is for the graph , both for realtime or on measured data.4.2 The setup screenEntering in the button makes the system show the setup screen, where theexperiment is formed or loaded from a saved setup.The screen shows the usual structure of zones and button , but are now dedicatedto the block sequencing.Each operation inserted is a “block”, an “experiment” is a sequence of blocks, theblocks are chosen from the list on the left.we see, on the left, a list of “tools”, each one with a specific function or measure:the name of those can be found in the bottom list on the same side.The experiment sequencing is then reduced to drag&dropping from the logo list tothe composition area: the connections to the latest created block are automaticallyadded to the diagram.During this first phase, you do not edit the values applied to the sample, but justdecide the “structure” of your test sequencing.A button helps in returning back from a wrong entryDelete : it erases the selected object on the composition area, selectedby clicking on itAt the end of the editing of a simple experiment the screen will look like thisEach block has a number that sequentially identifies it Note that isselected and the relative setup bar for the block is shown on the left side.The first button on the left will transfer the experiment setup to the startingscreen, ready to be performed.4.3 The block parameters’ structureEach different action is described by a block and has its specific parameters to besettled.Anyway the structure of the parameters’ side bar is in common with all the differentblocks: looking at a side bar we can see it.On the top there is the name of the blockThen the specific parameters of that block: inthis case, being a cyclic waveform, the twovoltages and the ramp rate are specified.Being cyclic a repeatable waveform, a numberof cycles is specifiedThe data acquisition part allows the variationof the sampling rate and the way the data iscollectedAn average feature allows cleaner datathrough averaging over the sampling intervalThe termination part let you end the block atthe occurrence of specified eventsThe setup part takes care of the hardwaresetup of the potentiostat in that specific block4.4 Block’s common parts: the data acquisition setThis part is related to the way the system read and memorise the data : the twomodes specified are Points per second, and you have then a short list of samplingrates to choose from, and Seconds per point , and there you can specify in hour,minutes and seconds the time between the samples.The average checkbox allow the user to average the data within the data acquisitiontime with the following logic: the system runs with 100 samples per second, that aretaken independently from the data acquisition values.If you check the Average box, with an acquisition rate of 5 sec for point , the datamemorised is the average of 100 x 5 sec = 500 samples avedraged4.5 Block’s common parts: the termination setA block execution can end for the complete execution of the specified actions or atthe reaching of specified quantities or measure: many electrochemistry experimentshave variable execution time depending on the starting condition of the sampleand/or environmental factors.In order to manage this the termination sub-menu allows to choose between a list of directmeasuresinstantaneous values calculated frommeasured quantities,or integral values i.e. quantities like charge orenergy, where the item is an integral vs. timeof an instantaneous value.The allowed operations on those quantities are comparison with threshold valueson both higher or lower band, and on delta value over time.Combining the two comparison values in the two operations allows the user tospecify a working band or a dead band to avoid.Surpassing the given limits leads to an action that can be the end of the experimentor the jump to the next step.The user is asked to decide between the two options by a pop-up menu4.6 Block’s common parts: the hardware setup parametersIn this part the hardware is set to perform the specific task by deciding the mode,the scales and other parameters.The screen that pops-up is the following:each line of the set can be selected by clicking on it and choose from the list.5- PRIMITIVE FUNCTIONSwe call “primitive” functions the basic blocks the experiment is based on.These functions are written in the firmware of the system and are executed by thepotentiostat itself after the configuration is received.For each function a set of parameters is specified, here following the list and someuseful hints5.1 CELL logoThe cell has no parameter : this block just connect the cell to the CE electrode ordisconnect it.Its status can be “CELL ON “ (with the box green) and “CELL OFF” (with the boxred)To swap between the two positions, just double click on the box in the flow chartRemember that an experiment is headed by a cell off status, so remember to insertthis block , with cell on , before polarising the item.OCV measurements are allways performed with the cell off, but OCV does notautomatically open the cell, so do this before the measure.5.2 OCV logoThe OCV block measures the Open Cell Voltage of the cell: the relative parametersare as followingThe cell will be observed for the specifiedtime with a given sampling rate.The ability to perform averaged measuresgreatly enhances the precision of them.The termination menu can help inproceeding only when the cell is stabilisedto a certain levelThe system just memorise the latest OCV voltage in the execution of theexperiment, and use it as an offset if the voltages of the step following are specifiedVs. Open Cell.The data taken are memorised in the file, so OCV variations can be recorded.5.3 STEP logoThis is the potentiostatic/galvanostatic block: as in any polarising block, the sameapproach is considered for constant voltage and constant current measures.The parameters (here shown in potentiostatic mode), are varying accordinglyThe step will have this duration, expressedin hh.mm.ss.This is the potential in voltsThese are the common parts to all thesteps5.4 RAMP logoThe ramp is a linear segment with a start point different from the end point: is usedby itself, in scanning voltammetry, or as a method to bring the potential to thestarting point of a cyclic waveform without capacitive overcurrents.These are the start and the end potential involtsThis is the ramp slope expressed in mV/sThese are the common parts to all thesteps5.5 CYCLIC logoThe ramp is a linear segment with a start point different from the end point: is usedby itself, in scanning voltammetry, or as a method to bring the potential to thestarting point of a cyclic waveform without capacitive overcurrents.These are the start and the end potential involtsThis is the ramp slope expressed in mV/sThis is the number of repetitionsThese are the common parts to all thesteps6- THE PLOT AREADuring the experiment, and on data previously saved, is possible to performdifferent operations, to display exactly the plot needed.The real-time display is intended to let the user know precisely what is going on,while the off-line screen is dedicated to the reporting and the exporting of theobtained data.The analysis of the data is out of the aims of this program: one can used existingprograms from preferred sources, thanks to the ability of Junior Assist to save theresults with different formats.6.1 AXES, CURSOR AND ZOOMThe plot area has two selection boxes on the top and one cursor display:the axes can be selected between the same list that include the two voltages, thecurrent , the temperature and the time.In this easy way, any plot (I vs. V, V vs. time and so on) can be obtained.The cursor position is read in the relative box: due to the presence of the full set ofdata , it is not changing at the change of the displayed plot.By holding down the mouse’s left button on the plot and dragging it through thescreen is possible to zoom on the highlighted area.To zoom, drag from the top left to the bottom right of the desired area, to return atfull picture, drag an area from bottom right to the top left.6.2 THE REAL-TIME PLOTDuring the running of the axperiment the axes can be selected on the fly, the sameas the cursor position , that determines the readout relative at the selected position.No other function is allowed during the experiment in order to avoid the slow-downof the computer and eventually the loss of some data reception.