There are a number of ways in which you can configure alibava-gui. Once this is done, one can always save that configuration. To save the current configuration click on the Save or Save As items on the File menu of the main window. Saved configurations can be loaded afterwards either by given the configuration file path when starting alibava-gui or by choosing a configuration file through the Open item in the File menu. Most of the configuration parameters can be accessed through the Settings menu as shown in Figure 4. Each of the menu items will allow to configure different aspects of the alibava-gui behavior.
The DAQ has a number of parameters:
All those parameters can be set by clicking on the DAQ item of the Settings menu as show in Figure 5
There are two more options that control the behavior of the system.
Enable Busy
Checking this box will make the alibava motherboard send a busy signal through the LEMO connector used for the laser pulse. This will only happen during the Radioactive Source run mode. Remember that the signal output is an LVCMOS 3.3V signal that needs to be terminated to 50Ω. When the signa lis "on" it meands that alibava is BUSY, ie, it is not sensitive to new triggers.
Be careful with this option since you may send the strobe pulse to a laser system that may be in danger when receiving the strobe while switched off.
When running in RS mode, Alibava measures the time of the incoming trigger with an internal TDC. The way it works is that the trigger starts the TDC and a system clock raising edge stops it. Since the system clock has a period of 25ns, this will be the maximum value measured by the TDC.checks this box, the system will use a 100ns clock derived from the system clock. This allows to measure longer times and, therefore, to have a measurement of the full pulse shape by plotting the average of the signal as a function of the TDC measured. This is scketched in Figure 6.
The Beetle parameters are set by clicking on the Beetle item of the Settings menu as show in Figure 7. At the top of the dialog you can select which chips will be active during the acquisition.
The BEETLE chip configuration parameters are described in Table A-1
One can also configure the behaviour of the Beetle comparator. This is only usefull for those daughter boards that process the output of the comparator to produce an autotrigger.
The upper button is used to enable and disable this feature. Then one selects the chip and sets the appropriate parameters like the polarity, trigger mode, threshold, some advance parameters and, also, the channel mask and threshold corrections of the individual channels. The beetle chip documentation provides more information about all these parameters.
The trigger for the Source run can be configured by clicking the Trigger item in the Settings menu or the Trigger button by the RS run radio button. The dialog is show in Figure 9. Units are in mV.
There are two types of trigger. One is the Trigger in, which uses two signals to produce the trigger. The input signals are supposed to be negative, as well as the corresponding thresholds. The trigger will be fired it either both (AND) or any of the two (OR) are below the threshold programmed.
The other trigger type is the Pulse in trigger. For this one there are two thresholds, one positive and one negative. The board will produce a trigger for any signal which is either above both values (a positive signal) or below both thresholds (negative). If the input pulse falls between the two values it will not produce a trigger.
The data is monitored while acquiring data and this is displayed in a number of histograms. The parameters defining how to find clusters, etc. are displayed in the analysis configuration window shown in Figure 10
The only parameter of the Laser run is the delay (in ns) that can be wet in the Laser item of the Settings menu or in the text entry by the Laser radio button.
Units are in nano seconds
The plugin configuration dialog box appears in Figure 12.
There you can specify the plugin language, which can be either C++ or Python, a folder to add to the search path, the name of the library or Python module to load and the function to call. The Find Symbols button will open another window with a list of all the callable functions in the plugin. Select one and click OK. Otherwise you will have to type the function (or hook) name. Also note that when clicking on Browse for the Library, both the path and the library file name will be filled. alibava-gui will also select the language based on very simple assumptions.
alibava-gui can compute pedestals on-line either by making a pedestal run at the very beginning or estimating the pedestal and noise while taking data. However, for some run types pedestal calculation makes not sense. This is the case of the calibration, laser synchronization and laser since, a priori, some channels will always have the same amplitude. Nevertheless, we would like to see the real pedestals subtracted on th emonitoring histograms. To solve this we can either make a pedestal run or load a pedestal file via the Load Pedestals item in the Settings menu. Likewise, we can always save on a separate file a set of pedestals we are proud of via the Save Pedestals item in the Settings menu.
The format of that pedestal file is:
The comparators on the Beetle chip have a non negligible spread and therefore the chip provides mechanisms to aling the thresholds of all the channels for a given working global threshold. This is a quite involved procedure but alibava-gui provides an authomatic, yet slightly slow, procedure to do it.
It is worth noting that this will only work for on the alibava daughter boards where the Beetle chip autotrigger is enabled.
The procedure is as follows:
There is, on the left, a series of check buttons that will perform a specific task.
Select the desired analysis and click the start button. You can click again the button to stop at any time. Then click cancel if you do not want to keep the settings or OK if you want to keep them.