Catching POSIX signals with labview

Hi,
is there a way to catch POSIX signals with LabVIEW.
Im building a LabVIEW Client (Linux AND Windows) to a non LV Server
(Linux, C). All works fine except the catching of the interrupts sent
by the server. The server sends interupts using POSIX signals. For full
functionality I should be able to catch this signals. How can I do
that?
Thanks for your help
Ulrich

Interesting project!
I looks like a few people have tackled decoding the data (both WWV and WWVB) using reciever modules that create a digital signal stream and Arduinos to decode the data.
How about GPS based time? Here is reciever/decoder module that provides a decoded serial data stream:
http://www.parallax.com/Portals/0/Downloads/docs/prod/acc/GPSManualV1.1.pdf
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~
"It’s the questions that drive us.”
~~~~~~~~~~~~~~~~~~~~~~~~~~

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Attached is a workaround that answers this problem.
W. Brown
Attachments:
Notifier_Problem.llb ‏91 KB

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Sometimes this is incorrectly referred to as the atomic clock.
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Interesting project!
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Write signal with time stamp

hii...
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-Keep Learning-
Attachments:
Read Circle Encoder.gif ‏22 KB

Hi Dani,
here's the two-loop version...
When you use the local you wouldn't need the queue at all... But using locals may lead to race conditions (not in your simple vi, but general) - locals don't provide "atomic" data access.
In Labview the wire is equivalent to variables in text programming languages!
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Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome
Attachments:
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Acquire generated signal with this hardware ?

Hello everyone,
I didn't really know where to post this, I apologize if it's the wrong place.
I'm very new to the LabView thing, and I have for project to trigger an injector and so to create a digital signal like this:
Due to the characteristics of the signal (110V, 10-20A, injection duration: ~20ms), someone recommended me this hardware (sorry if I'm not allowed to post these links):
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I have designed and built injector drivers. To get a waveform somewhat like the one you showed requires a sophisticated and fast control circuit. I would not call that a digital signal. It may be controlled by some kind of logic signals, but that is an analog signal. No programmable power supply I have seen is fast enough to come close.
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Is it possible to get 2-ch signals from TDS2012 oscilloscope at the same time with LabVIEW "7.0"?

Hi, everyone.
I've been trying to get the signals from 2-ch of Tektronix TDS2012 oscilloscope at the same time using IVI connection with LabVIEW "7.0"
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Error -1074110451 occurred at IviScope Initialize With Options.vi
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I don't need to sticking to IVI and any method to achieve my goal will be welcome.
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I think your problem is that the instrument specific driver is version 7.1 and you are using the class driver with 7.0. You can create your own 7.0 driver by downloading the LabWindows driver and using the Import CVI Instrument Driver under the Tools>Instrumentation menu.
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Where can I found hardware to get analog signal from VCR and work with labview and then sample this signal in very high frequency?

I am trying to build a Digital Video Recorder using Labview. The problem is that I found that Labview sample the signal in the order of milisecond. I wanted it to be in the order of microseconds. Also I am looking for a cheap Hardware solution if it is possible

Your question does not make a lot of sense to me, so I will just point out a few things.
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s that acquire at higher rates.
If this information isn't really what you were looking for, perhaps you could clarify your question.
Bruce
Bruce Ammons
Ammons Engineering

How interface N5181A MXG signal generator with labview by using LAN Interface????????????

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You can set the IP Address on the instrument. You may need to be in the same subnet of your controlling computer, so you may need to set your computer's IP Address to something static.
Use VISA. It makes life easier if you decide to use another bus (like GPIB, USB, serial, etc). In MAX, create a network session with the static IP address you set the instrument to and use that as the VISA Resource.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Excel with Labview 6?

I'm trying to get Excel '97 to work with Labview 6.02, but I'm always receiving error message: -2147319784: "old format or invalid type library". I modified windows registry as told in LV knowledgebase. After that I could see Excel components in ActiveX pull down menus. I have tried to run demos such as "Open Excel And Make visible.vi" but they always output the error message. I have tried this with both Windows 2000 and NT. Other programmes, for instance MS Access, seem to work fine. What is the catch?

Anders,
You have run into a special case of the problem that actually has a work around for it. However, you will have to contact LabVIEW technical support to obtain the temporary fix since they need to keep track of all the people with this special case.

Using excel to generate signal in labview

Hi there
I am having a trouble in generating a signal in labview using excel and then plotting it as waveform.
In excel file, I have 2199 rows and 9 columns with time in second and I want to plot time against other columns except column 1. In rows, I have text in first one.
Any help much appreciated.
Thanks
Solved!
Go to Solution.
Attachments:
Data File Modified.xlsx ‏554 KB

smercurio_fc wrote:
You haven't shown us any code, so we don't know which columns you're using. However, you should be aware that Excel and LabVIEW use different epochs: https://decibel.ni.com/content/docs/DOC-8733.
Thanks smercurio the link appears to be broken so anyone who tries just remove the "." at the end.
The best solution is the one you find it by yourself

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Hello,
I am developping an application with LabView RT on a PXI RT system. This application acts as an instrument (non controller GPIB), and I need to assert the SRQ line. How can I do that ?
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Hello Alfonso,
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Finally, please refer to Abhinav's earlier post about the sample rate on the 9237 module. As he described, the NI-DAQmx 8.3 driver will only allow you to set the sample clock to integer divisions of 50k (50,000/n, where n can be 1, 2, 3...13). Since the maximum divisor is 13, the smallest sample rate that can be used is 3.846 kS/s. You can check what value the driver is actually using for the sample clock by reading from the SampClk.Rate property of the DAQmx Timing property node.
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Error, in Getting started with Labview. Chapter 3, part 4.

Hi.
Still struggling on, trying to find the time to work through the "Getting Started with LabVIEW" document.
Only 19 days left to go, and I'm still only in chapter 3!...
Right. In the "Saving Data When Prompted by a User" exersise, part 4...
4.   Right-click the Signals input of the Write To Measurement File
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Problem is, that option is greyed out, so not available!...
I did what the instructions said, I right clicked on the "Signals" input, and it doesnt do what it says on the tin!
Any pointers?   Please don't mention search the help, I've crashed the entire LV environment 3 times now, trying to search for something in there. It's OK if it finds someting, but it seems to bomb at times, when there is some ambiguity when searching.
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Regards.
Dave Baxter.
Technical Manager: AR-UK Ltd.
AR United Kingdom
OK... Who let the smoke out?

Hi Dennis, and everyone else..
That is not how it looks when first dropped on the BD. On my machine, it is partialy expanded by default, after you clear the Configure dialog that pops up ocupying most of the screen.
Again, if it makes a difference to the way the Right Click shortcut menu works, it should be documented in the Getting Started document, especialy as it seems to be a critical point.
OK, explain this...
I've just rubbed out the save to file VI, cleaned up the broken wires etc, and then planted a new one on the BD. Once I cleared the Configure dialog that covers up most of the screen before you see it the first time, the VI was partialy expanded. I forget the exact list, but "Signals" was not at the top.
I did *EXACTLY* the same again, deleted it, cleaned up, and then planted a fresh new one. That DID appear that time with nothing but the "Signals" item showing, and two down caretts below that, indicating more items.
So......
Why the different behaviour each time, on the same BD, in the same session. Some underlying working data not being correctly initialised when invoked? Of course, that never happens, right? ('C' programmes eh?)
Trying some more, it seems the behaviour loosley depends on just how close to the edge of the While loop grey border you place it.   Odd.   I have a 1280x800 screen to play with, and a 1280x1024 second screen I use for the Getting Started document. That is the absolute maximum I can have, due to hardware limits.
I also find, that if you fully expand the "Write to Measurement File" VI block, then fully collapse it, then expand it again, all the items in that list have changed places! Why?
I had noticed earlier that there is no uniformity in the layout of even the items common to many if not all VI blocks (error in, and error out to name but two) Sometimes one is above the other, sometimes the other way round, sometimes they are not even ajacent to each other. Has that been done as a source of minor ammusement or something?
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End of the day now...
Regards.
Dave B.
OK... Who let the smoke out?

Want to input interference signal in labview + perform bandpass filtering/demodulation

Hello to whom it may concern,
I have a fiber-based OCT system linked to a Tektronix TDS 2024B digital oscilloscope, with which is showing the interference fringes of the low-coherence lightsource. The signal is linked to the computer using the NI DAQ Board USB-6251. I want to input the fringes using Labview and not only that, but to perform a high-pass filter command, along with an active full-wave rectifier and a lowpass filter to see the group velocity of the interference pulse. Now I am new to using Labview so this question be a little elementary, however I am struggling here. Any helps are greatly appreciated.

Hello!
Basically you will need to measure a signal in LabVIEW and then perform some processing on it. First I suggest, if you haven’t, getting familiar to LabVIEW and DAQmx that are basically what you will use for acquisition. For processing, you might find useful some toolkits we have for filters and signal processing. I’m linking information on these subjects, if you wish, you can download them in evaluation mode and take a look at the examples on how to use those functions.
NI LabVIEW Digital Filter Design Toolkit
NI LabVIEW Advanced Signal Processing Toolkit
Getting Started with NI-DAQmx
Getting Started with LabVIEW
Regards,
Alina M

How to switch central frequency fastly with labview and USRP?

Hello everybody,
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There is an attribute "LO Frequency" that you can use to lock down the frequency of the local oscillator. Then, when you set the "Carrier Frequency" attribute, the difference between the carrier frequency value and the LO frequency value will be realized by frequency shift in the DSP in the FPGA. Changing this "digital" frequency shift value is much faster, since you don't have to re-tune the local oscillator.
Let's say you're sweeping from 2.44 GHz to 2.46 GHz. Set the "LO Frequency" to 2.45 GHz then Commit. Then, in your loop, program the "Carrier Frequency" attribute from 2.44 GHz to 2.46 GHz. In the loop, it will only program the digital frequency shift, which will happen much faster.
Another tip is to use the property node to program only the attributes you want to change, rather than the niUSRP Configure Signal.vi (which sets many at once).
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Catching POSIX signals with labview

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