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| The supplied instrument control software consists of two layers. At the upper level, a simple Windows dialog application, "SR3820Counter", offers a convenient panel that allows the input (A, B or one of three internal test sources) to be selected, an update rate to be specified and all eight output measurements to be displayed. A further display area shows one of the measurements in a larger font size, as well as displaying a graphical trendline display. |
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The program also supports data logging to text file of the output measurements, with data being written directly in CSV (comma separated value) format for easy import to other programs. The software includes a sub menu where the voltage input thresholds can be set for the two inputs. |
At the lower level, a
dedicated ActiveX control known as "SR3820Comms" takes
care of all communications to and from the instrument. Two main
modes of operation are therefore possible. Users who simply want to
operate the counter "out of the box" need do no more than
plug it in, install the driver and software, and then use the SR3820
Universal Counter software to control it. Alternatively, when the
counter is to be used as part of a computer controlled test system,
then the user can develop software to control it via the SR3820Comms
ActiveX control. The control eliminates the need for users to write
the low-level code needed to send commands to and receive responses
from the counter, allowing them to concentrate on developing the
higher level program to run their experiments. Typical applications
include:
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| The SR3820Comms control can of course also be used at
the same time as other SIGNAL RECOVERY software
ActiveX controls, such as SR3830Comms, allowing sophisticated
systems to be assembled. For example, five APD's (avalanche
photodiodes) could each be connected to the inputs of a model 3830
multiplexer, with the output being in turn connected to the A input
of a model 3820 counter. Using both controls a user-developed
application program could sequentially count the pulses being
generated by each APD.
Both the top level SR3820 Universal Counter software and the lower-level SR3820Comms ActiveX control include comprehensive on-screen help files, while examples of how to use the control in LabVIEW, Visual Basic, VBScript, Visual C++ and Excel are also supplied.
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| Input | ||
| Impedance | 1 MW, DC coupled | |
| Threshold | ||
| Direct | –0.2 V to 0.5 V in 1 mV steps | |
| With x10 probe | –2 V to 5 V in 10 mV steps | |
| Polarity | Event counter triggers on rising edge of signal | |
| Sensitivity | ||
| Direct | -15 dBm/50 W (23 mV rms) at 100 MHz, -10 dBm/50 W (0.7 V rms) at 120 MHz | |
| With x10 probe | 1 V pk-pk sinewave at 125 MHz | |
| Min Input Slew Rate | ||
| Direct | 200 mV/µs | |
| With x10 probe | 2 V/µs | |
| Abs. Max Input | < 50 V DC | |
| Frequency Range | DC to 125 MHz min, 160 MHz typical | |
| Timebase Accuracy | better than 5 ppm/degree C, 0 to 50 degrees C | |
| Reporting Intervals | 100, 50, 25, 10 and 5 ms | |
| Functions | ||
| Frequency | 0 to 125 MHz | |
| Avg Period | > 8 ns | |
| Avg Duty Cycle | 0 to 100%. Measured by sampling with a 65 MHz clock. | |
| Avg Pulse High or Low Time | > 5ns. Computed from Duty Cycle and Frequency | |
| Events | 0 to 9,999,999,999 counts | |
| Logic Probe | 0 = input voltage below threshold, 1 = input voltage above threshold | |
| Indicators | ||
| USB | Front-panel LED turns on during USB communications | |
| EVENT | Front-panel LED turns on when the input signal is above the threshold | |
| USB Connector | Rear-panel, female USB connector for connection to the PC or a USB hub | |
| USB Cable | Supplied complete with 6ft (1.8m) USB A/B cable | |
| General | ||
| Power Requirements | <500 mA @ +5 V DC, supplied via USB | |
| Dimensions | ||
| Width | 5½" (134 mm) | |
| Depth | 4½" (114 mm) | |
| Height | 1¼" (32 mm) | |
| Weight | 9.9 oz (280 g) | |
| Software | A CD containing the full applications package for Windows 98/2000/XP allowing threshold and input to be adjusted, and measurements to be displayed and saved is supplied with each unit. SR3820Comms ActiveX control also included for use with compatible programming languages, and examples provided of its use in C++, VisualBasic, VBScript, LabVIEW and Excel. Both top-level and ActiveX software includes on-screen help. | |
Already using a model 3820?
The model 3820 previously carried the SENSE-ations brand
name. The hardware is unchanged from units carrying this older name, but
the SR3820 Universal Counter software and SR3820Comms ActiveX control
software are both new.
Software supplied with the SENSE-ations branded product included a program called PELauncher that was installed within the Startup programs group, as well as an ActiveX control (UCounterX) and application program (UCounter.exe). The PELauncher program was started when the computer booted and then ran in the background, monitoring USB bus activity. When a model 3820 Counter was plugged in the launcher program then started the UCounter.exe application software.
This approach is no longer used and the new SR3820 Universal Counter software is started in the same way as most other programs simply by clicking on the icon in the Start Programs menu. The SR3820Comms control is installed and registered during software installation and hence is available both to the SR3820 Universal Counter software and to user-written programs.
The new SR3820 Universal Counter application software generates data logging files that are compatible with those created by the older package, so in most cases users of the older software will get better performance by completely uninstalling it and replacing it with the new programs, which are available free of charge by clicking the link below.
Download Software
The SR3820Counter, SR3820Comms ActiveX control, and sample files are
available by download from this website
Product support and upgrades are automatic and free of charge to existing users of the model 3820 Universal Counter. If you have already purchased the product and installed the software then you can simply download and install any later software version by clicking the link below.
To check if you need to upgrade, see the product version number on the distribution CD or in the program's "About" box and verify if this matches the version given below. If it is a lower number then you should upgrade.
| Current Version Number: | 2.00 | |
| Date: | 13th October 2004 |
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801 South Illinois Avenue, Oak
Ridge, TN 37831-2011, U.S.A. (865) 482-4411 All Rights Reserved. |