Ubitekk CC1 Manuale utente
CC1‐Handheld
CoincidenceCounter
USER’SMANUAL
Rev.1.02
June1,2015
www.qubitekk.com
Contents
1. Principle of Operation 1
1.1 Overview..........................................................................................................................1
1.2 What is Included...............................................................................................................1
1.3 Powering the Unit.............................................................................................................2
1.4 Navigating the Menus ......................................................................................................3
1.5 Setting up a Measurement...............................................................................................5
1.6 Making a Measurement....................................................................................................6
2. Settings 7
2.1 Description of Counting Process......................................................................................7
2.2 Coin Window....................................................................................................................8
2.3 Dwell Time .......................................................................................................................8
2.4 Gate Chan........................................................................................................................8
2.5 Subtract Acc.?..................................................................................................................8
2.6 Trigger..............................................................................................................................9
2.7 CH1 Delay........................................................................................................................9
2.8 Firmware..........................................................................................................................9
3. Serial Interface 10
3.1 Serial Interface Setup.....................................................................................................10
3.2 Programming Commands ..............................................................................................10
3.3 Sample Code .................................................................................................................11
4. Customization 12
4.1 Overview........................................................................................................................12
4.1.1 The Rabbit RCM3400 Microprocessor.....................................................................13
4.1.2 The Altera Cyclone IV FPGA ...................................................................................13
4.1.3 Default Firmware......................................................................................................13
4.2 Uploading Custom Firmware..........................................................................................14
4.2.1 Accessing the Programming Ports...........................................................................14
4.2.2 Programming the Rabbit RCM3400.........................................................................15
4.2.3 Programming the Cyclone IV FPGA ........................................................................18
Appendix A. Electrical Schematics and Connections 20
A.1 Top Board (LCD Board).................................................................................................21
A.2 Bottom Board (Processor Board)...................................................................................22
A.3 Pinout Table...................................................................................................................25
1
Principle of Operation
1.1 Overview
The CC1 is a low-cost, handheld coincidence counter intended for use with single photon
counting experiments. The unit can detect and count TTL electrical pulses with nanosecond
resolution and a maximum count value of 2,097,152 pulses per channel. Pulses that occur
simultaneously on Channel 1 and Channel 2, within a specified “coincidence window,” are
treated as “coincident” pulses and are measured and displayed by the unit (max coincidence
count equal to 2,097,152).
An LCD display on the front of the unit allows easy viewing of all measured single and
coincidence counts. This display, in addition to the push buttons on the front of the unit,
provides a simple interface for displaying results and setting up measurements. A USB
connection on the side of the unit provides power to the system while also allowing for optional
serial control of the device by a computer.
The CC1 comes pre-programmed with all of the functionality described in this manual; however,
it is capable of much more. The unit contains both a re-programmable microprocessor (for
handling the user interface and serial communications) and a re-programmable FPGA (for
handling high-speed pulse counting). Both of these devices can be programmed by the user to
implement a wide range of features.
In the Appendix section, the user will find the necessary documentation for programming the
CC1 for custom applications. Whether it is implementing a time histogram recorder,
expanding/modifying the existing features of the CC1, or developing a custom device for use in
implementing new cryptographic protocols, the CC1 is a flexible platform that will greatly simplify
and speed your development effort.
1.2 What is Included
The CC1 Handheld Coincidence Counter ships with the following materials:
a) 2m USB cable (USB-B)
b) CC1 Coincidence Counter
c) Rabbit programming cable (2mm)
d) Retractable USB cable (USB-mini)
e) Development software and programming file
f) USB-to-AC power module
The various components (with their respective labels) are shown in Figure 1 on the following
page.
2
Figure 1. Components included with CC1 Coincidence Counter.
1.3 Powering the Unit and Connecting Inputs
The CC1 is powered through its USB port. The USB cable provided with the system should be
plugged into the side of the unit as shown in Figure 2.
Figure 2. Power over USB connection.
The other end of the USB cable can be plugged into a computer USB port or plugged into the
included USB-to-AC power connector, as shown in Figure 3.
a
b
c
def
3
Figure 3. USB-to-AC Adapter.
Once powered, the CC1 will display a startup screen for five seconds on the unit’s blacklit LCD.
The unit’s “Count Screen” will then be displayed as shown in Figure 4.
Figure 4. Count Screen on startup.
To connect signals to the CC1, three SMA connector jacks are available at the top of the unit.
To detect coincident pulses, Channels 1 and 2 must both be connected to a pulse signal. If the
counting of single and coincidence pulses should be gated (see next section for more details),
then the third channel (“GATE”) should be connected to the associated gate pulse.
1.4 Navigating the Menus
The CC1 has six buttons on its front face. The buttons, along with signal connectors and
peripheral ports, are shown in Figure 4.
4
Figure 4. CC1 Buttons and Ports.
5
To configure the CC1 for a measurement, press the“menu” button. The CC1’s Menu Screen
will be displayed as shown in Figure 5.
Figure 5. Menu Screen.
Pressing the “menu” button again will return the user back to the Count Screen.
The Menu Screen contains six settings that can be changed by the user. These settings will be
covered in the following section. The various settings can be viewed by scrolling up or down in
the menu using the “UP” and “DOWN” arrow buttons.
When a setting needs to be changed, the setting can be selected for modification by pressing
the “ENABLE” button. The setting value will blink, indicating that it is ready for modification.
Again, the UP” and “DOWN” arrow buttons can be pressed to change the setting value. Once
complete, press the “ENABLE” button again to continue scrolling through the menu.
1.5 Setting Up a Measurement
Prior to any measurement, the measurement parameters for the CC1 should be configured. The
next section of the manual will describe each parameter and discuss their impact on the
measurement. The default settings for the CC1 (upon power up) are shown in Table 1 below:
Setting Value
Coincidence Window 1 ns
Dwell Time 2 s
Gate Chan. Disabled
Subtract Acc.? No
Trigger Start/Stop
CH1 Delay 0 ns
Firmware Ver 2.001
6
1.6 Making a Measurement
Once all measurement settings have been adjusted, the “menu” button should be pressed to
return to the Count Screen. With the Count Screen displayed, press the “ON/OFF” button to
start or end a count.
Once the “ON/OFF” button has been pressed, the details of the count measurement will be
displayed on the LCD as shown in Figure 6.
Figure 6. Count Screen after measurement.
Once the measurement is complete, the counts will remain on the screen until a new count is
initiated.
NOTE: If the unit is being triggered in “Continuous” mode, the counts will only remain on the
screen for a short period of time before resetting to zero and beginning the next count.
7
Settings
2.1 Description of Counting Process
Pulses detected on Channel 1, Channel 2, and the optional Gate channel will be counted as
coincident pulses based on a number of settings made prior to the measurements. In general,
the simplest measurement of coincidence is as shown in Figure 7:
Figure 7. Simple coincidence measurement described.
Two pulses will be counted by the CC1 to be coincident if:
a. The time between the rising edges of the two pulses is less than the coincidence window
If the GATE signal is enabled, then the two pulses will only be counted by the CC1 as coincident
if the following two conditions are satisfied:
a. The time between the rising edges of the two pulses is less than the coincidence window
b. The GATE signal is enabled during both rising edges
Figure 8 represents a coincidence measurement with the GATE signal enabled.
Figure 8. Coincidence measurement with a GATE signal.
Indice
