The read out program: 25.06.final-read-out-fast.vi

fastest version of the read-out program, reduced graphical display (only displays the actual measurement, the gauss-fitted histograms of the drifttime with the values and the drifttime);

writes out several files:

last-drifttime.dat : value of the latest drifttime in ns; (ascii value)
drifttime-backup.dat : the actual drifttime (in ns) will be appended with time and date and the number of the top and bottom signals;(ascii table)
rawdata"X".bin : binary file of the rawdata; "X" is for the numbers of 0 to 9 for the file-loop; overwrites always the oldest file;
currentfile.dat : stores the name of the newest binary rawdata file of the file-loop;(ascii value)

Before starting the program you can set several parameters for the data acquisition program:

(don't forget to make all changed parameters default: right click on value -> data opartions -> "make current value default" and than save the program)

Card settings for PCI-9812:

Number of the data acquisition card: 0 (begins with 0, 1, 2, ... ; the oder in the PC is from top to bottom PCI-slot);
Number of the trigger source: Channel 0 (default value), the incoming triggersignal is detected on this channel;don't change this parameter
A/D Count: 1000 (default value, max lvalue is 1000) , length of data which will be taken if a trigger is detected, kimited on internal buffer of the card;don't change this parameter
Reserved Buffer for A/D Data : 999 (default value) (the program reserves 999+1 =1000 values);don't change this parameter
Sample Rate: 10 MHz (default value, means 1 timebin=100ns), frequency depends on the internal clock, sampling rate = frequency of source clock (40MHz) divided by 2,4,6,8,...1024(max) ;don't change this parameter
Post count (delay): 0 (default value); time till card starts data acquisition after trigger event; don't change this parameter
trigger mode: delay trigger (takes about 350 ns to start data acquisition + post count);don't change this parameter
trigger polarity: positive trigger;don't change this parameter
trigger level: Trigger in units of 8 mV, e.g. 0 mV, 8 mV, 16 mV, ...., 96mV, 104 mV, ... (range -1 to +1 V);

Program settings:

run until max #: 999999 (default value) (means that the program runs 999999 times with the specified number of samples), here you have the possibility to set a limit how the program should take the specified number of samples;
now at run #: indicator to return tha actual run number;
read # samples: 5000 (default value), number of trigger events = samples; all found signals will be tested to satisfy the cuts and than sorted in short or long drifttime, filled in 2 different histograms, the histograms are than gauss fitted and the difference of the 2 means will be calculated = drifttime
now at sample #: indicator to return the actual sample number;
file-path to store the files: 4 files will be stored in this specified path.
now at file #: returns the number of the newest binary rawdata file with this name: rawdata"#".bin , # in the range from 0 to 9, it is a file loop after file number 9 it starts overwritting file number 0 and so on...;
file size: returns the size of the binary rawdata file, should be "# of samples" * "A/D count (1000)" * "2 bytes", for example 5000*1000*2 Byte = 10MByte;
delaytime of channel 1 and 2: there is a 600 ns delay of the signals on channel 1(bottom counter) and channel 2(top counter) and no delay on the pick up signal. To correct this delay you can specifiy here the delay in ns for each channel;
max iteration for gauss fit: here you can set a limit for the maximum number of iteration for the gauss fit of the signals (used in subvi "gauss-fit-2" and "gauss-fit-3"), the maximum number I noticed was 220 iterations, the other break conditions (mse value and the change from one iteration to the next of the Chi2) can be found and modified on the block diagram of the "Levenberg Marquard Prep (modified).vi ".
# number of bins for histogram: set the number of bins for the 2 histograms of the drifttime (15 is default value).

Peak-finder:

You have to specify a range within the program should search for the right signal:
start channel #: (the first timebin to begin the search)
bins channel #: (the search length in timebins)
e.g.: Channel 1 and 2: start at timebin 0 (default value) and the length is 20 timebins(default value).
For channel 3 you have to specify 2 ranges for the search:
For the bottom signal ( 3-1) for example start at 20 with a length of 60 and for the top signal (3-2) start at 150 with a length of 100.

Cuts on fitted signals:

You have to set cuts on the gauss fitted signals for all 4 different signals (bottom(channel 1), top(channel 2), pick up bottom (ch3-1)and pick up top (ch3-2)):
1. amplitude range ( lower limit 0 mV(default value), upper limit 1499 mV (default value) )
2. sigma range in timebins ( lower limit 0 (default value), upper limit 5 (default value) )

Displays and histograms:

Displays current signals
display histogram short drifttime ( 3-1 -1): displays the drifftime of the signal difference of the pick-up signal(coming from the bottom counter) amd the bottom signal, with the parameters of the gauss fit (amplitude in mV, sigma and mean in ns, and the number of entries in the histogram);
display histogram short drifttime ( 3-2 -2: displays the drifftime of the signal difference of the pick-up signal(coming from the top counter) amd the top signal, with the parameters of the gauss fit (amplitude in mV, sigma and mean in ns, and the number of entries in the histogram);
display of the mean difference of the two fitted histograms = drifttime in ns.

The control buttons:

STOP (after an additional run with saving all files): when pressed during execution, the vi will take an additional run with the specified number of samples ;
STOP (immediately, at current sample, with saving all files) : stop after the next sample with saving all values in the files, becareful the binary rawdata file will be shorter ("# of samples" * "2000 bytes");
START daq : starts the program after compiling it (put it into "run mode"), or if pressed before compiling, the pogram will start immediately;

This Page was updated by Tobias Titz.
Last modified: Fri June 29 16:05:19 CET 2001