Difference between revisions of "Tools"

Latest revision as of 11:43, 21 December 2016

Init

While most of the configuration information is saved in the Windows registry, some important initialization data is saved now in the file stmafm.ini. These data can be accessed and modified within the tool window Form_Init, or the ini file can be changed directly in a text editor. Apart from the ADC/DAC calibration the STMAFM program usually should be restarted to put the changes in operation, at least as HW changes are involved.

ADC0/DAC0 ... Offset + Gain: Determines the calibration data of the ADCs and DACs of the Createc ADDA board.

DAC6-9 Offset: Input Offsets of an optional 16bit DAC Board

Machine Name: This text is added in front of all the filenames. Used to identify the instrument or user. Select from the picklist or write the text dirrectly.

HW_Platform: Select from a picklist the actual hardware configuration: 0: No Board 1: C6711 : SBC6711 Board only used 2: C6711/USB2 V2 : SBC6711 DSP Board + USB2.0 connection through OPAL Kelly Board with SW Version 2 3: C6711/USB2 V3 : SBC6711 DSP Board + USB2.0 connection through OPAL Kelly Board with SW Version 3 4: C6711/Flashboot: SBC6711 DSP Board + USB2.0 connection through OPAL Kelly Board with SW Version 3 wiht boot from Flash Mode 3 is the only mode available under Windows 7 operation 5: C6657 with Ethernet Connection

AD/DA_Board_2_Mode: Select from a picklist the operating mode of the second AD/DA Board, if installed 0: None  : Not installed 1: PLL  : Used as PLL for NCAFM operation 2: AD/DA  : Used as second normal AD/DA board

AFM_Mode: Enables AFM Mode of Operation.

PLL_ZIHF2LI: Enables use of external PLL from Zurich Instruments instead of internal PLL.

PLL_ZIHF2LI_ExtNodename: Device name of the ZI PLL

Invert_Biasvoltage: Set to true to permanently invert the biasvoltage.

Enable_mVInput: For compatibilty with older versions. If enabled Voltages are input in mV.

TakeInternalHVGainvalues: If false program reads the gain values directly from HV amplifier. If true HV Gain values can be input from user.

Ramp_Slider: Enables the use of the new slider hardware for coarse movement

Load_Preampvalues: If true: When loading a datafile into the STM program, the Preamp gain as well the type of the preamplifier are taken from the file. If false: Preamp gain and type are not changed. Protects against uncontrolled switching of the preamp. In analysis mode this parameter has no effect, the preamp values are always loaded

SRSLockin_Enable: Enables the use of an external lockin SRSxxx

CHMode_Icon Channel: In case of Const height mode imaging, this value determines the channel used for the icon stored in the dat file.

Save Scan Forms: Allows to remember the postion and number of channelforms for LAT and Vert Manipulation

Compress_Files: Enables the compression of dat files. Uses ZIP. The parameter info is not compressed.

Enable ExtInt: Allows to reset the DSP board by an external signal if the custom HW is installed.

Show_Hints: If true short hints are shown the mouse cursor is above particular buttons.

Stmoutfile: Path to a specific file loaded into the DSP during boot.(Used for test purposes,usually empty)

STM_Manual: Path to the STM Manual file.

STM_Helpfile Path to the STM Help file.

STM_Website: URL to the STM website.

Press the Calibrate_ADCs Button to transfer the calibration data on the ADDA board.

Data Recorder

Tip Etching

Under the tools menu you can select this part of the program to etch STM tips. Press the Start Tipetch Button to start the tip etching. A voltage is applied to the tip and simultaneously the current is recorded. Etching will be stopped when the measured current is below a given treshold current. Pressing the Stop Tipetch button will immediately stop etching. During etching the current is recorded and displayed in the I(t) plot.

DAC Voltage Voltage applied to the tipetching setup. A positive voltage of about 5-6V has to be applied to the tip wire.

Etch On/OFF Time For DC etching set Etch Off Time to 0 msec. In case of pulsed etching the parameters determine the period and on/off ratio of the applied square wave signal.

Current Filter Filters the measured current signal to avoid stopping of the etching due to noise.

Etch Level If the measured current is below this treshold current level, the voltage will be switched off.

ADC, DAC Channels Selection of the ADC, DAC channel used for tip etching. ADC [1-3], DAC [1-5]

Resistor Value of the series resistor to measure the current

SpecGrid

This is a separate tool which allows you to analyze Gridspectroscopy files. It is intended to cover only the basic features. More detailed analysis has to be done by the user.

We suggest for exmaple MatLab for this purpose.

Basics

Gridspectroscopy creates 2 files, one which contains the spectroscopy data in binary form (file extensionand .specgrid) a normal dat file which contains the related image (file extension .specgrid.dat). Specgrid files can be very large, therefore an original file can be divided into several smaller files. (There exists also a Windows 7 64bit version to handle larger files) The Pspcegrid30 program allows you to inspect individual spectra, extract these spectra in separate ASCII based spectroscopy files (either single files or all files) and to display 2d images out of the spectroscopy data.

File Format Specgrid

Format Specgrid File (Extension .Specgrid)

It starts with 1024 byte long header:

   version:                integer;
   nx,ny:                  integer;
   dx,dy:                  integer;
   specxgrid,specygrid:    integer;
   vertpoints:             integer;
   vertmandelay:           integer;
   vertmangain:            integer;
   biasvoltage:            single;
   tunnelcurrent:          single;
   imagedatasize:          integer;
   specgriddatasize:       integer;
   specgridchan:           integer;
   specgridchannelselectval:   integer;
   specgriddatasize64:       int64;
   xstart,xend,ystart,yend:  integer;
   dummy:  array[1..236] of integer;

Latest version is 4. Beginnng with version 4 you have xstart, xend which give you the specgrid line numbers. Ystart, Yend correspondingly. For older versions you have to calculate it:

 xend:=round(nx/specxgrid);
 yend:=round(ny/specygrid);
 xstart:=1;
 ystart:=1;

Specgridchan: Number of Channels in the Spectra. Specgridchannelselectval ist the bit pattern which detemines the type of selected channels. (Similar to vertchannelselectval) vertpoins: Number of points in a single spectrum.

After the header:

V and Z spectrum data: Each vertpoints long. 4byte floating point values.
V:  4 x vertpoints bytes for V
Z:  4 x vertpoints bytes for Z

After the V,Z data the spectra data are following in 4byte float format. Spectrum1 (X=1, Y=1), Number of channels: specgridchan*(vertpoints*4) byte for each spectrum grid point. Spectrum2 (X=2, Y=1), ........