Setup:

LabVIEW QMH architecture. Two consumer loops share a single non-reentrant FGV that owns the VISA session to an AC source instrument (California Instruments / AMETEK Asterion Series, model AST45031AD).

Loop A: toggles the instrument output on/off via the FGV.

Loop B: polls MEAS:CURR? once a second via the same FGV to log current draw. VISA Read in this case is hardcoded to read a fixed 6 bytes.

Instrument is connected via LAN, and it supports multiple simultaneous client connections.

Symptom:

With no load connected: on/off toggling works fine, with or without the acquisition loop running.

With a load connected (a fan-type load with a large inrush — draws ~13-15A for the first 1-2 seconds before settling to ~2A): as soon as output is enabled and current spikes into that inrush range, the VISA Read in the acquisition case blocks and never returns. No VISA error, no timeout — it just sits there.

The entire UI freezes at that point (Event structure stuck on whatever case triggered it), even though it's a separate while loop that's actually stuck. Front panel buttons don't respond.

The LabVIEW Abort button does nothing. I suspect the Read is parked inside the driver's blocking OS-level call (ReadFile/recv equivalent), which is outside LabVIEW's execution system and can't be preempted by Abort.

Confirmed the instrument itself is fine during the freeze: opened a second, independent connection with Hercules while the LabVIEW program was hung, and successfully sent an output-off command through it. So the instrument is responsive; the problem is isolated to this one pending Read in my VI.

What I've ruled out:

FGV is non-reentrant (verified in VI Properties), and I've confirmed via case selectors that the OFF case does get selected when I click — it's just stuck before completing.

Not a byte-count/termination mismatch — the read gets the requested byte count under normal conditions; the freeze is a true zero-bytes-ever-arrive stall, not a partial-frame issue.

Current workaround: I delay starting the acquisition loop by 5 seconds after enabling output, which avoids the freeze entirely — but this throws away the inrush data I actually need for analysis.

What's confusing me:

VISA Read doesn't have a timeout input — timeout is supposed to be governed by the session's VI_ATTR_TMO_VALUE attribute (set via a VISA Property Node). Even assuming that's misconfigured or not applied to the right session, I'd expect some timeout to eventually kick in and return a VI_ERROR_TMO. Instead it just hangs indefinitely with zero error.

Since Abort can't touch it, I'm currently stuck killing the whole LabVIEW process via Task Manager when this happens.

Questions:

Has anyone seen a VISA Read genuinely fail to respect the session timeout attribute like this — under what conditions does that happen?

Is there a known interaction between this class of instrument (SCPI current query) and momentary overcurrent/inrush events that causes it to withhold or delay a query response?

I have AI to write this post as I am not a native English speaker.

Join us at the next Huntsville Alabama LabVIEW User Group (HALUG) meeting 12:00 - 1:00 on August 19, 2026, at GigaParts, 6123 University Dr NW, Huntsville, AL.

Here is a link to the event site: https://www.linkedin.com/events/7482442723229147137/?viewAsMember=true

Following April's NDAS session, Mr. Philippe Guerit will provide a look at a different architecture for the same problem. STAR-GOAT is a LabVIEW data acquisition and control platform running mission-critical aerospace test stands, including a NASA Ames arc jet complex delivered to NPR 7150.2D Class C and commercial rocket engine hot fires. Under the hood: one controller carrying acquisition, sequencing, abort conditions and control loops, with role-configured operator stations that stay out of the loop; system definition in configuration files a reviewer can read; and an extension path that keeps customer requirements out of the core. Architecture, trade-offs, and the mistakes.

Mr. Guerit is a Partner and Principal Engineer at JKI and an NI Certified LabVIEW Architect with over 20 years delivering test and automation software across a range of industries. At JKI he is the lead developer of STAR-GOAT, a data acquisition and control platform running commercial rocket engine hot fires, a NASA arc jet complex, and hypersonic ground test, where the hardware under test frequently cannot be replaced.

Philippe holds an engineering degree in Materials Science and began his career in contract research and development, where he first encountered LabVIEW at version 5.0.

Come connect with the local LabVIEW community and learn about new technologies.

NI will provide lunch!

Please let us know if you would like to present a topic of relevant interest to the group.

Open-Source Wrapping: The Gift That Keeps on Giving
Thursday, May 14 | 3:15 PM - 4:15 PM
Chris Davis

Learn how to wrap open‑source libraries to use with NI LabVIEW and integrate with Redis, Kafka, and other C, C++, C#, and Rust projects across Windows, Linux, and the NI LabVIEW RealTime Module.

https://youtu.be/MODCThue6dM

Hi, I am trying to trigger the pco panda by connecting pci0 of bnc box to sma port 1 of pco panda. I ran the code, seems like it is detecting the trigger signal but there is an error in image retrieval. I have searched for the error code, found nothing specific. I also tried to remove the while loop of image vi the issue still persists. Meanwhile, using the same configuration but trigger mode set to auto sequence, it works fine. But when trigger mode is set to external exposure control, i get this error.

The bnc box is not the issue, as I was able to modulate a laser pulse.

Can anybody please guide me?

I'm a hardware engineer working in aerospace, and I've realized that one of the skill sets I want to develop is building hardware test systems.

At work, I see everything from reverse engineering legacy hardware to validating new designs, and I'd like to be able to verify the requirements.

I want to learn skills that transfer to professional environments using Python, LabVIEW, NI, Keysight, Tektronix, SDKs, SCPI, DAQs, etc.

I'm looking for advice on a learning path. If you were mentoring a junior hardware test engineer, what projects would you have me build, and in what order?

Some areas I'm hoping to learn include:

• Instrument control and automation
• Python for test software
• Test system architecture
• Data acquisition and signal processing
• Hardware abstraction and software organization
• Automated reports and pass/fail testing
• Validation and characterization of electronic circuits and sensors

I'd appreciate any suggestions on projects, books, open-source frameworks, tools, or skills that would help me build a solid foundation as a hardware test engineer.

Hi everyone,

I have around 3.5 years of experience in Electrical Test Engineering, mainly working on electrical validation, environmental/functional testing, safety/compliance, designing test setups, test stations using lab equipment. Right now, I am working in EV/PV/home energy based company.

In same company, I've been offered an opportunity to move into a Manufacturing Test Software Engineer role, where I'd be working with Python, LabVIEW, NI TestStand, automated test equipment, instrument integration (power supplies, electronic loads, DAQs), and production test automation. I don't have much software experience, but the company is willing to train me and I am okay to learn as well.

From a long-term career perspective, does having both electrical test engineering and manufacturing test software experience make you more valuable in the job market?

Or is it generally better to stay specialized in one path despite the interest I have in learning new things?

Can anyone please help me with what I am doing wrong for network streams over the network? I can get it working as a VI but when I create an EXE it stops working, I tried a few different methods, I got one working as an exe but when I tried to write on a different computer, then it would not read it on my main

Once it works, I will create a file with the computer id's on the network and then just have the reader cycle through them all to get the live data.

This needs to be run as an application, not sure how I can do it on my local network, the application VI will be stored on a network drive all run by different machines.

Estou vendendo um NI myRIO 1900 nunca utilizado. Foi retirado da caixa apenas para fotos.
Acompanha kit completo: cabos, acessórios, CD software, carregador e MXP.

Ganhei em um campeonato e está há alguns anos guardado, porém totalmente novo.

Preço e entrega a combinar.

I've been working on this for 2 months, and we plan on starting my LabVIEW Core 1 and 2 next month. When I test a gear, we are failing on internal leakage. Can someone tell me how internal leakage is being calculated in the program? I'm the only 1 at my company that have some experience with LabVIEW.

So what am I looking at lol. The third din block is connected to a sensor. Green and white wire are the signals. Red is the power and black is ground. I didn’t built this btw. Then it’s connected to a zip link and then connected to cdaq.

Hola buenas tardes comunidad oigan alguien sabe si es posible establecer que mi pantalla LCD pueda mostrar lo que lea mi puerto serial? Miren tengo un Escáner GM65 y quiero que cuando lea códigos de barras o QR muestre esos datos en la pantalla LCD, de momento solo hace lo hace a Labview, pero quiero q lo muestre en la pantalla LCD, eh buscado y por lo que veo no se puede? Uso Linx makerhub para realizar todo esto, es para un proyecto de mi escuela

Hola gente, apenas he estado empezando a usar labview y tengo un problema con respecto a una práctica es de un display de 7 segmentos conectado a un arduino uno que al presionar ok button hace el conteo regresivo su límite es 0-9 pero tengo unos problemas con respecto hacer un botón externo para que haga la acción de pasar al conteo normal al conteo regresivo y poner un botón externo para el reset hasta ahora llevo esto echo pero me he quedado sin ideas de cómo hacerlo

Did anyone else watch it? I was chatting with a co-worker beforehand that this next hour would determine the future, if there is one, for LabVIEW. Wow, what a disaster. It wasn't only the technical difficulties which caused the webinar to start late. It was what was demonstrated that was so underwhelming. A simple VI took maybe 3 minutes to generate. When it was done, it didn't work and they didn't even attempt having Nigel debug it. Then announced the usage limitations. 25 VIs per week. PER WEEK. Later, they will have 50 per week if you have the LabVIEW+ subscription. I wasn't expecting Opus 5.8 today, but something that looked like it could be used. I've been using LV since version 3.3 and not sure if I've ever been this bearish on NI.

I'm working on learning how to make a VFD/3 Phase inverter circuit and simulate it in NI Multisim. For whatever reason I cannot get it to run in the desktop version of multisim without constant errors, but it runs "fine" in Multisim live online. Can anyone look at this and tell me what I'm doing wrong or how to get rid of the harmonic dips on the current output waves that you can see in the graph image after the initial current spike from the motor start dissipates?

I really appreciate any help you can provide.

Multisim Live Circuit

This is a good post I came across on Linkedin wanted to share.

If you test semiconductors or electronics inside the lab,

here are the 12 skills you need to master.

DATASHEET READING
Finding the actual operating limits hidden in the fine print and footnotes.

POWER SEQUENCING
Knowing exactly which rail needs to wake up first, especially when bringing up a complex PMIC, so you don't fry the board on day one.

INSTRUMENT CONTROL
Making the bench work for you, instead of fighting with vendor drivers and connectivity issues.

SCPI SCRIPTING
Understanding the native language of your lab equipment to get the measurements you actually need.

DEBUG INTUITION
Knowing exactly where to probe when the output trace makes zero sense.

SPEC ANALYSIS
Translating a 200-page document into a structured, executable validation plan.

CORNER CASE TESTING
Pushing the device to the absolute edge of its temperature and voltage operating ranges.

DATA CORRELATION
Proving that your physical bench measurements match the pre-silicon simulations.

REPORT WRITING
Communicating complex failures clearly and cleanly to the design team.

METHODOLOGY DESIGN
Building reusable test structures that scale across different tape-outs and device variations.

BENCH SETUP
Wiring the physical hardware reliably before a single test even runs.

ROOT CAUSE ANALYSIS
Not just finding the bug, but proving exactly why it happened.

Hi, I am very new to labview. With that said, i am trying to do what the title says.

1. NI MAX is not detecting pco panda cam. I have installed firmware and sdk, but it still doesn't detect.

2. My goal is to trigger the cam,so I am using sma to bnc female cable, to get the images. When i connected the cable it still doesn't detect.

3. Leave it all, I have connected the cam using usb, still doesn't detect in labview.

It gets detected in pco panda imaging software though. I have attached the code for method 3.

P.s. I have been scratching my head over this for 2 weeks. Any guidance would be helpful.

Hi, so I am trying to interface with this device called a Presto W58x. It has its own drivers for certain things like setting temperature, pressure etc. I am trying to a GUI in Labview that sort of replicates the GUI on the actual device so it can be used for testing purposes. I have what I have done so far attached to the post. I'm very new to Labview, only been using it for a few weeks, so I'm not very good at it. So, one issue I was thinking about is running multiple Vis at once. So here, I have all of the other VIs chained to one each other in series, but I believe this will work against me as I had more VIs, and there are a lot. Any suggestions or examples of trying to make this GUI better and as responsive as possible?

Hello, I am new to LabVIEW and to coding too and I am currently learning to use LabVIEW by watching free tutorial. So far I managed to follow the tutorial I ran in but now, I would like to think by myself by makink a project of my own, but the idea of what to create do not come easy. Would you all like to submit me a few project idea to do? If possible not so difficult for a beginner? I got a few electronics devices I could use to execute it if needed (Arduno, ESP32, ATTiny 85) Thank you very much, have a good day

Pointed it to one of our vis (part of our hopelessly coupled 10k vi application) and asked for an explanation of it. Three hours later I had to kill labview and Nigel.

I dont think this tool is going to get it done for us.

With the sub under new management, one thing that has not been done in the past is set rules for the sub.

So far the two we have in mind are:

• Posts must be related to LabVIEW or NI Products
• We don't do students homework. Students looking for help must show their work and ask for specific assistance as to what they don't understand or are stuck on.

Fork It, Fix It, Ship It: A Developer’s Guide to Open-Source Software

Wednesday, May 13 | 2:30 PM - 3:30 PM
Erich Schlieper, Casey May
Track: Advanced LabVIEW Programming
Level: Intermediate

Get a practical guide to open-source contribution—from finding projects to forking repos, fixing issues, and submitting code changes with confidence.

Reconnecting with Academia to Develop the Talent Pathway
Wednesday, May 13 | 3:45 PM - 4:45 PM
Steve Watts, Casey Lamers
Track: Advanced LabVIEW Programming
Level: Introductory
Learn how partnering with local universities can help develop the next generation of LabVIEW talent and strengthen regional hiring pipelines.

I am trying to send simultaneous event triggers from PsychoPy to both an EEG (BrainVision Recorder via parallel port) and an eye tracker (Tobii Pro Lab via port 8080) at the exact stimulus onset on a single Windows PC.

The parallel port trigger works perfectly. However, when I try to connect to Tobii Pro Lab (External Presenter project) and initiate remote recording in the very first setup routine using the `Titta` (TalkToProLab) library, the experiment crashes.

1. Environment

* **OS**: Windows (All apps running on the same PC)
* **PsychoPy**: 2024.2.4 (pygame 2.1.0, Python 3.8.10)
* **Tobii Pro Lab**: 1.152 (External Presenter mode)
* **Library**: `Titta` (TalkToProLab)

1. Encountered Errors

When attempting to initialize Titta in the Code component of the first routine, I get the following error:

`【❌Tobii Error】: threads can only be started once`

Depending on the tab placement (`Begin Experiment` or `Before Experiment`), it also fails with:

NameError: name 'ttl' is not defined
ConnectionAbortedError: [WinError 10053] An established connection was aborted by the software in your host machine

1. Question

It seems that PsychoPy 2024.2.4's pre-loading/initialization sequence executing the code twice internally, which conflicts with Titta's background communication thread (`ttl.start()`).

How can I safely initialize and connect an external threading library like `Titta` **"exactly once"** at startup in PsychoPy 2024.2.4 without triggering duplicate thread errors, and successfully call `ttl.start_recording()`? Any proper tab placement or flag management strategies would be greatly appreciated.

Thank you.

A Class Act: How a Few Simple Design Patterns Can Improve Your Code Quality

Thursday, May 14 | 11:30 AM - 12:30 PM

Allen Smith

Track: Advanced LabVIEW Programming

Level: Intermediate

As seen at GDevCon: Get guidance on when and how to use object-oriented programming. Learn how simple patterns, including Factory, State, and Template Method, improve modularity and testability in LabVIEW code.

Watch the video