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Scratching my eyeballs with a nail, or using PPLs - which is less painful?

June 11, 2015, 5:12 am
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LV 2013 - More PPL madness.

 

I'm building an addon system, where the user can make addon pieces that are recongnizeable by my host piece and have them work together.

 

I am moving some of my code into PPLs (Packed Project Libraries) in order to make that code available both to the main host and to these addons.

 

I have a control called "Units".  It's an ENUM with values like "degC", "degF", "degR", "N-M", "Ft-Lb", etc., etc.  Since it's used everywhere and might be useful in the addons, I moved that control and the code that goes with it (units conversion, etc) into a PPL of its own.

 

Fine.

 

I have another PPL that manages channel selectors.  It sorts the list of channels alphabetically or by hardware type, or by cal date, and manages the pop-up menu, and manages a units indicator that is associated.  (If you switch to watching a temperature channel, for example, it switches the associated indicator to "degC".

 

So, it uses the UNITS indicator from the first PPL.

 

I discovered an error in my structure - the ChanSel manager uses the UNITS indicator from my Units LVLIB (the original), not the one from the units PPL. As a result, there are lots of coercion dots when I use the ChanSel manager, because the units I feed it from outside are the copy from the PPL, but it uses the original LVLIB copy.

 

So, I changed the ChanSel manager to use the UNITS control from the PPL.

 

But now, it complains when I BUILD the ChanSel manager: "Cannot Build the application because the folllowing source files are in the destination directory.  You must build the application to a different directory from the source files", and it refers to the UNITS ppl.

 

I understand that it uses the UNITS PPL as a source file, but what is the problem with having a source file in the same folder as a dest file?

 

And then it gets even more maddening: if I put all the PPLs (I have about 15 now) in individual folders, then the build process will COPY the UNITS PPL into the same folder that it builds the ChanSel Manager PPL in!  In other words, it does itself exactly what it complained about me doing.

 

And, on top of that, when it's time to open the project that USES them, it now will complain that there are TWO copies of the UNITS ppl and it doesn't know which one to use where.

 

Is there any sense behind this?  If so, shine a light on it, please.

 

Do I have to make a post- build action to put them where I want them?, or is there a Don't-be-so-dang-stoopid option I can turn on?

 

 

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How can I connect an optical mouse to DaNI robot through Labview Robotics ?

June 11, 2015, 5:12 am
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How can Read signal from optical mouse by DaNI robot  to use it in path tracking?

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How to read text in variant input terminal on control pane

June 11, 2015, 3:30 pm
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Hi all,
I've created a 3D array of double and I've sent it to sub vi to a variant terminal. How to read info that is displayed on the terminal? The message on the terminal that I want to read is:

 

'': 3D array of
'': double [64-bit real (~15 digit precision)]

[500x5x0]


variant.png

 

I'd be grateful for any help!

 

Best regards,

Pete

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Labview driver for Electric Load PLZ70UA, PLZ-30F Series

June 11, 2015, 3:44 pm
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Hi,

I couldn't find the labview driver for Kikusui Electronic Load PLZ70UA, PLZ-30F Series in NI Instrument Driver Finder or in the website.  Please help me to find the location, where I can download driver for this model, so that I can talk to the instrument.

Thanks

Truc

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Writing a New TDMS File Every Hour

June 11, 2015, 4:21 pm
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Hello NI Community,

 

I am currently trying to write a VI that creates a new TDMS file every hour and records displacement data from my CompactDAQ Ethernet Chassis. Please see the code attached. Right now the code only appends the current TDMS file and does not write a new file on the given time interval. I would like for a new file to be created every hour, so the files do not get insanely big.

 

Also my displacement data is not writing data anywhere near the correct collection rate. Right now it seems to be collecting one data point every second, where I have the collection rate at 100. 

 

Any advice would be greatly appreciated!

 

Thanks.

Chris

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reentrancy

June 11, 2015, 6:24 pm
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I'm using LabVIEW 2014.

 

Reading through the many posts on VI Reentrancy, I am still left with one fairly basic question about VI reentrancy:

 

Let's say I have a VI which i want to set to 'Reentrant' (Shared or Preallocated), in order to execute several copies simultaneously.

Let's say this VI is typical, containing numerous subVIs (which themselves call numerous subVIs and so on).

 

If I want to see maximum-performance parallel execution of all copies of my VI (avoiding bottlenecks of multiple instances waiting to use the same subVI), am I required to visit every one of the subVIs in the calling heirarchy, and manually set its execution state to reentrant? And its subVIs too, and so on? 

 

OnceI get down to the level of the built-in LabVIEW functions, I assume multiple instances of the same (built-in LabVIEW) function will execute within each reentrant VI in parallel (e.g. as inline code) without causing bottlenecks? Is this true for every built-in function offered by LabVIEW (e.g. signal processing, datacommunications etc)?

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User Input State Machine does not work as expected - unsure what to do

June 11, 2015, 9:00 pm
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Hi all,

 

I'm designing a UI for a program I wrote and trying to implement it with a state machine. The machine doesn't really work at all; it just transitions between states without seemingly doing the checks it should be doing. Before I added the wait (for debugging), it would work as expected, until I'd changed two values, then the whole thing would freeze. Also, no matter how I set the Window Appearance settings, the abort button has gone away when running this VI.

 

This input should basically run the user inputs through a series of checks to make sure they're entering sensical data, before sending it out to the main VI. One problem I have is that range_min and range_max are interdependent with their checks:

 

  1. They must both be positive, and nonzero
  2. range_min must be less than range_max
  3. range_max - range_min must be greater than or equal to 40.

It seems this interdependence is what causes the crash when removing the wait statement, but I can't be sure.

 

I've attached a zip containing the VI so you might check it out. Let me know what you think.

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LIFA

June 11, 2015, 10:03 pm
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Hi All,

 

Could anyone can explain the function of LIFA, stepper motor configure palette? Thanks in advance

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Phase angle between voltage and current(HELP!)

June 11, 2015, 10:17 pm
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Hey guys! I'm stuck with my assignment(project) and I need some help here! So I'm required to find the phase angle between voltage and current as a measurement and I've googled a lot but I'm still very lost. I'm using DAQ assistant as the input signal and currently I'm doing a test circuit. Really appreciate if you guys can help me, like a sample of a basic calculation would help too! Thank you!

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labview not detecting usb-gpib

June 11, 2015, 10:50 pm
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Hey, I just started using Labview, and my first eperiment would involve dealing with a HP multimeter (model-34401 A ). I was using the GPIB/USB of Keithley KUSB-488B. I installed the drivers for the USB and for the muiltimeter. Additionally, I isntalled VISA and NI 488.2. Then, I connected my multimeter to my laptop using the USB port. When, I try scanning for instrument drivers it shows nothing. I even went to NI MAX and VISA, yet I'm unable to see my device. Could anyone please help me out ? 

Thanks.

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Automating Interaction with MPLab IDE using LabVIEW

June 11, 2015, 11:31 pm
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I am using MPLAB Real Ice as a debugger for my code. I need to set certain predefined breakpoints in the IDE which I am planning to automate by giving line number of code to LabVIEW and then LabVIEW should send the command to set that breakpoint. While exploring options in LabVIEW for Inter-Application communication, I came across via TCP ans via ActiveX.

 

 Which is the better option in this scenario? What approach should I start with? Please note that I am trying to communicate only with the IDE and not Hardware.

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Synchronization 35 Hz and 2 kHz with Producer/Concumer method

June 12, 2015, 12:41 am
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Greetings

I am still new to LabVIEW, but I have gotten a basic understanding of it.

 

I am working on a project where I have 3 signal, each of these is being sampled with 35 Hz, 35 Hz and a 2 kHz.

The 2 kHz signal is from a NI6024 and the samples to read have been set to 256. The two 35 Hz have no timestamp on them, so I have used a Build waveform and used the timestamp from the NI6024 to give them a timestamp.

I am supposed to analyses, display them on graph and log the data to a file. For this reason, I have used the Producer/Consumer approach inspired by the following https://decibel.ni.com/content/docs/DOC-26558.  Where I have 1 producer loop, where the three of my data acquisitions unit is placed. Then three consumer loops, one for analyses another for display the data and the third is data logging in TDMS-format.

 

The three signals have to be synchronized and this is where I am stuck.

The queue that the producer/consumer method use, works after the principle FIFO and so I thought the data would be synchronized. But this doesn’t seems to be true, when I look at the graph, their seems to be a 10 sec. delay between the fast and the slow sampling rate. But in the TDMS file, it seems synchronized at least when I look at the timestamp.

 

Is there anyone who might help me?

 

Regards Christian

 

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How to stream live on front panel by given browser url

June 12, 2015, 1:17 am
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Hi,

 

I have an IP Camera which can be viewed online through a given url. 

However, i am stuck trying to display the live stream on my front panel. DAQ-Max is not needed because the camera is already integrated to software.

 

Attached is my VI so far, and here is the website: 

http://153.20.39.66:8051/ 

Click on mobile mode to see the live video stream.

 

error message.png

However there is an error at the "READ JPEG file" when i run the VI. I dont really understand the error?

 

I just need to link the VI's  front panel to the live stream video via url. How do I do that? Thank you in advance! 

 

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Passing .net reference between different vi or sub vi files

June 12, 2015, 1:39 am
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Hello

 

I am a bit new to Labview. I am trying to communicate with a hardware using .net assembly. Functions to initialize the hardware driver is written in c#. I am using a constructor node and then Invoke node. There is a reference coming out of ' Invoke' node. I want to use this reference in different vi files; otherwise my Labiew program would become very bulky. I want to save this reference and use it according to my need ( in a same project maybe).

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NO access to the the FP1000

June 12, 2015, 2:29 am
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Hello

 

I want to to ask yo the following I am using the Measurement Automation explorer 3.1 and I am trying to conect me to the FP 1000. through Port COM 1.

I configured the port on the right way but here is not possibility acess to the FP 1000 module (the orange LED does not light ).

The FP 1000 is conected with the FP-DO-401 and FP-AI-110but all these module dont have anything connected and no function and no charges are used, how you can see on the foto attached.

My question is why I can not access to the the FP1000, eiterh with COM 1 or USB to RS 232 cable.

 

Thank you Helmut

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The Current Time is Incorrect on My LabVIEW Real-Time Controller

June 12, 2015, 3:00 am
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Concatenating multiple numeric data into string

June 12, 2015, 3:09 am
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1. I have to contain multiple numeric data into string. 2. Attached is VI. 3. problem is on front panel it seems very clean since I have created tabs. But on block diagram it seems very cluttered. How can I reduce it?
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Continous Digital output express vi gives error -200609

June 12, 2015, 3:29 am
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Using Express vi to generate continuous output on two digital ports of NI USB-6341 - extremely basic:

digital waveform input problem block diagram.png

To test, I simply right-click create a control at the data input of the express-vi and types in some data manually.

There are two digital lines dev1/port0/line0 and dev1/port0/line0 so I would expect this input to be an array of two digital waveforms each with one line of data. Right?

 

Below  is what it looks like and the error I get. Sample rate is set at 1kHz. 

digital waveform input problem.png

In the express vi, #samples to read is set at 4 (as wfm has) or 1k - it gives the same error.

 

  1. How can I fix this without going _inside_ the generated express code and change the buffer size, which I would like to avoid.
  2. Is the express vi generator broken for this particular - yet very simple and basic setup?
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Write to spreadsheet in separate cells

June 12, 2015, 3:50 am
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Hi Folks.

 

In the VI attached I am writing the time and amplitude of the signal to a spreadsheet. The problem is that they are in the same cell. I have used a tab delimiter but that will not seperate them. The rows are fine but I would like two colomns for time and amplitude. As you can see below they are in the same cell. How can I seperate them?

 

0.000000 0.068000
0.002000 0.068000
0.004000 0.072000
0.006000 0.068000
0.008000 0.068000

 

Thanks,

 

Mark.

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problem filtering a signal

June 12, 2015, 4:11 am
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Hi,

I am trying to read the signal from an accelerometer using LabVIEW and an arduino uno board.
The accelerator (352C33) is a high sensitivity sensor, approx. 105mV/g and my problem comes when I try to filtrate the signal. I am using different point to point filters but none of them works. Does anyone know how could I filtrate the signal properly? I can upload the programming I am using or the accelerometer specifications if necessary.
Thanks in advanced

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