We're your wireless ATE support team

Looking to say "hello" to someone who can help you with saying "good-bye" to wireless signal path problems, test equipment failures, and configuration challenges? Can't find a Lab Brick software set up guide, or need a specific Lab Brick application question answered? You're in the right place. Vaunix provides technical support to our customers and future customer contacts worldwide. We're here to answer the who, what, where, when, why, and how of cellular infrastructure, RF communications, and wireless ATE problems of all kinds, including 5G. We're especially experienced in finding unique ways to employ our portable, programmable devices to create efficient and nimble RF and microwave ATE set ups. Our staff of experienced radio technicians and test engineers is here to help 24/7. Start by reviewing our FAQs, our informative blogs, and our technical resources for immediate insights, and submit your questions directly to our technical team by using the simple form on this page.  And if your needs are especially urgent, just call us at 978-662-7839. We look forward to helping you.

Hardware FAQs

Are custom Lab Brick designs available?
What is the Lab Brick's housing material?

All Lab Brick products use a rugged aluminum enclosure.


If I specify the external reference input option will the unit still include an internal one?

Yes. The user has the option of using either an external 10 MHz reference or the internal reference. This selection is made through the GUI under the settings menu.

What is included with a Lab Brick purchase?
Each unit is shipped with a 6-ft. USB cable and a thumb drive containing the graphical user interface (GUI) software and a soft copy of the user manual.
Can I lock multiple Lab Brick signal generators to an external reference or daisy chain them to one internal reference?

Yes. Multiple Lab Brick signal generators can be locked to a common external reference. 

Can I modify the RF output power of a Lab Brick signal generator?

Yes, as an example, LMS-203 can be adjusted for an output from -30 to +10 dBm.

How might we use Lab Brick phase shifters to measure the radiation pattern of an antenna array? The set-up would include one signal generator, one 1-to-4 splitter, four phase shifters, and a four-port antenna. Vaunix specifies phase shift accuracy of its Lab Bricks as +/- 2.5 degrees. In a scenario using multiple phase shifters, does each one apply a phase shift with an error of +/- 2.5 deg. or will all have the same error (that is, all having +1.3 deg.)?

We rate the phase accuracy of our Lab Brick phase shifters very conservatively at +/- 2 deg. but it is typically much better. Measured data for an LPS-802, for example, represents typical performance at 5.8 GHz: Error is often less than +/-1 deg. at this and other frequencies. Although there is some variation from unit to unit, error is always very similar (but not guaranteed).


Learn more in our blog on this subject.

Do Lab Brick Signal Generators offer pulse modulation, sweep triggering, external reference input, or optional RF outputs?

Quite simply -- yes.

Learn more >>

What is the phase accuracy and repeatability of Lab Brick phase shifters?

Vaunix Lab Brick phase shifters are conservatively rated. For example, phase accuracy measurement of an LPS-802 at 5.8 GHz shows phase error of less than 1 deg. with a maximum of 1.7 deg. 


Learn more in our blog on this subject.

How much power does a Lab Brick signal generator use?
Lab Brick products are USB functions, and as such are required to use less than 2.5 watts of power. Lab Brick signal generators typically use 2 watts of power, which is a fraction of what a conventional signal generator requires. Lab Brick digital attenuators use less that 0.25 watts.
Do I need to purchase an AC/DC adaptor or some other power supply to run a Lab Brick?
No. Lab Brick products get their power through the USB port of a PC, laptop or powered hub.

Software FAQs

Can I write my own code to control Lab Brick products?
Yes. We can supply a file containing the Windows programming API DLL for the Lab Brick products, along with a sample program which demonstrates how to use the functions in the DLL. The full source code and a Visual C++ 6 project are included for the sample program.
What is the best way to use Lab Brick Series Attenuators to cover 802.11ac and IEEE 802.11n Wi-Fi bands?

As the 802.11ac standard is increasingly becoming the successor to IEEE 802.11n, many customers have asked about the most prudent way to use our attenuators to cover both bands. We have two products for this application each providing attenuation in 0.5 dB steps. Learn more. 

Using Windows, is it possible to assure a Lab Brick Attenuators' switching speed, or does the Windows GUI just set up the profile and the microcontroller operates on the data? Is it also possible to vary the duty cycle between iterations?

The switching speed for the Lab Brick attenuators, shown on our Web site and on our data sheets is defined as the time it takes to change from one attenuation state to another. It does not include the time required to pass the instruction from the computer to the device.


The minimum timing speed of the attenuator is controlled and determined by its firmware along with constraints posed by how the USB bus works, and how the software is implemented in Windows. With the attenuator at the lowest attenuation setting, the process runs each time there is a USB “start of frame” which occurs at exactly 1 kHz. Consequently, the minimum time between any commands is 1 ms, which is also the minimum attenuator dwell and idle time. The fastest the attenuator can ramp and the fastest it can be changed by directly issuing commands to set the attenuator level is thus 1 ms per step.


That said, a USB host controller and its software can potentially send out commands to the device either faster or slower than 1 ms apart. However, exact timing is difficult to define as it depends on many variables including the type of host controller chip, its driver software, and how the application software issues commands. Writing an application to generate a precisely-timed series of USB command outputs is not trivial, but the result would allow the unit to run at near its 1-kHz maximum rate. The response and status messages from the attenuator will not keep up with the output. Vaunix provides .dll files, and drivers for Linux and LabVIEW for developing custom programming interfaces.


Duty cycle can be controlled with the attenuator’s ramp feature. In your example this could be configured using the attenuator’s dwell and idle times along with the attenuator’s bidirectional feature controlled through the user interface software. In addition, the attenuator’s profile function can be used for more complex cycles and it allows 100 discrete steps to be defined at any setting. The profile can be set to run once or continuously.

How do you connect multiple Lab Brick phase shifters to a computer via an Ethernet-to-USB hub while operating over a wide range of temperatures?

All of our Lab Brick products can be used with a powered Ethernet-to-USB converter. The phase shifters are specified for operation from 0o C to +50o C and are designed with components rated from -30o C to +70o C. Phase-setting accuracy will degrade slightly over temperature but all other specifications should not vary. We can also sample test or screen units over a specified temperature range if required.


The MTBF of Lab Brick phase shifters is greater than 1.5 million hr., and as they are entirely solid state with no mechanical parts to wear out, their operating lifetime is not affected regardless of how many phase changes are made. The time it takes to switch from one phase to another is up to 4 µs and the user interface allows dwell time to be set between phase changes as fast as 1 ms.

How can I simulate signal fades and dropouts for a system with an embedded transceiver?

It really depends on the sensitivity of the receiver that you are using, but the LDA-302-P-2 is certainly the attenuator that we would reccomend.

How many Lab Bricks can be operated from a single computer?
Lab Brick products are USB functions. The number of available USB ports determines the practical limit to the number of USB functions that can be operated from a single PC or laptop. Adding USB hubs can expand the number of USB ports. USB hubs can be purchased from the Lab Brick website.
If I plug four attenuators into four USB ports on a PC, can I address them with the attenuator software individually and change their attenuation separately, as well as simultaneously?

Yes. In fact, there are three ways you can control multiple Lab Brick attenuators:

Method 1: Control multiple attenuators independently

Method 2: Simultaneously control up to eight attenuators

Method 3: Writing your own attenuator control routines

Learn more in our blog on this subject and contact our techincal support team with any questions.

What is the best dwell time setting you offer in your attenuators?

The latest version of the attenuator user interface allows dwell time to be set up to 500s. To learn more about operating or programming Vaunix products or other topics, please contact our technical support team.

Is it possible to control the LDA-602EH attenuator with Python scripts?

We have many customers who use Python scripts to control their Lab Bricks. Our DLLs are designed to be straightforward to use from Python, and, as an example, it only takes a few lines of Python to set the working frequency and attenuation of an LDA-602EH. Here is an example of a Python script which sets the working frequency and attenuation, as well as showing the number of devices connected and the serial number of the first device.

When this script is run with an LDA-602EH attached the output is:

We would be happy to help your programmers understand how to use the Vaunix DLLs.

Can Lab Brick phase shifters be controlled using Linux?

Yes, all Lab Brick phase shifters can be run from Linux. Learn more in our blog on this subject. If you have any questions about operating or programming Vaunix products or other topics, please contact our technical support team.


How can I update my GUI to insure that I have the latest release?

It is the policy of Vaunix Technology Corporation to provide Lab Brick users with the latest GUI software, drivers and equipment manuals free of charge. All of this information is available for download from our website. Please visit our support page. Under the Software heading, select the product line. You will need to enter your contact information to proceed. Then you will be able to select the product line and type of software required.

Can I use a Lab Brick with LabVIEW?
Yes. LabVIEW drivers are available for Lab Brick customers from our secure FTP server.
Can I program a digital attenuator using VB6?
Yes. VB6 can only call out to external DLLs that use the old Win32 API calling conventions (what is normally declared as __stdcall in C). Newer DLLs, like the Lab Brick DLL use a newer calling convention that is easier to work with in the more recent programming tools. To solve this issue we built a special version of the attenuator DLL, that uses the older calling convention so you can call it from VB6.
What is autonomous operation?

Autonomous operation allows Lab Brick signal generators to operate from a stand-alone power supply or battery pack with or without USB supervision. Lab Brick signal generators will operate normally in the presence of a USB host, however, if DC power is applied and no host is detected, the signal generators will commence operation per user-defined settings. This feature is especially useful in embedded or remote applications where the user does not want to commit a PC or laptop. Battery packs can be purchased from Vaunix.

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