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How to call dll function with the double asterix parameter

November 27, 2018, 5:53 am
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I have a dll with header file. 

Function definition that I want to call is in header file and it looks like this:

 

 

DLL_EXPORT unsigned long CON_OpenInterface(
void ** ppHandle, 
unsigned long interface, 
const char * cmd, 
const char * response, 
char * pResponse,
unsigned long maxSize
);

I have parameterized call library function node as:

ppHandle: Numeric, Unsigned 32-bit Integer, Pointer to Value

interface: Numeric, Unsigned 32-bit Integer, Value

cmd: String, C String Pointer, <None>

response: String, C String Pointer, <None>

pResponse: String, C String Pointer, <None>

maxSize: Numeric, Unsigned 32-bit Integer, Value

 

But the function does not work. What am I doing wrong?

 

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Re: Connectivity issue from a server to Client OPC

November 27, 2018, 6:05 am
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Hi Taufeey,

 

Can you clarify what the RGA is and what you mean by "it shows connectivity with the RGA only but not with the Main LabVIEW program"?

 

Presumably, connecting to your device is not working in LabVIEW, but it is working in some fashion? More detail is (almost) always preferable to brevity. Thanks in advance.

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Re: How to Install OpenG Zip libraries on CRIO 9068

November 27, 2018, 6:23 am
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One other thing you might be interested in is the zip functionality built into the operating system on your controller.  Your controller is running the Linux RT OS and as a result you get all the power of Linux's community and tools.  It sounds like you already have your software written for the OpenG zip stuff so you should see if you can get that working.  But an alternative would be to use the System Exec.vi (found on the Connectivity >> Libraries & Execution palette.  Here you run commands like a command line.  With the zip package installed (my controller had it installed by default) you can perform a function like:

 

unzip "<Path to zip>" -d "<Directory to Extract to>"

 

I'm not sure what other functions are supported but this command will extract a zip to a directory.  One feature of the OpenG stuff I really liked was being able to extract a single file, and I'm unsure if the zip utility in Linux has that capability for now.  You'd have to read the documentation and help.

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Re: File overwrite

November 27, 2018, 6:27 am
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Hi GerdW!

Firts of all I am really thankful for your fast answer. 
why is there an additional wait in the case structures when you already have a wait in the main loop?

Because the myDAQ is checking too fast the lines and beause this the counter was too fast so I must use there an additional wait.

 

Why is there a generic IO constant in the false case of the AO case structure?

I can't answer this correctly. I use there a generic IO constant because I didn't know what I should use there, and with that VI the program worked. 
I wanted to use just the TRUE part of that CASE, but if I don't wire something in the FALSE part for the output then the "RUN" button will be broken. Do you know what should I do in these cases?

kerdes.PNG

 

IF "usertime" < "myDAQ time" THEN use "user time"

I know the logic, I understand it. The problem is that I don't know how to build up in LabVIEW and how to wire it.

Could you help me in these problems? 

 

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Re: SD card

November 27, 2018, 6:35 am
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Re: LAbview

November 27, 2018, 6:39 am
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It means you gave it the wrong password

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Re: LABVIEW S/N activation

November 27, 2018, 6:40 am
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To expand on what bseguin said, some licenses can only be used a set number of times, and it is possible that this serial has been used too much.  Contacting NI about this can clear up why it isn't working.  I wouldn't be surprised if NI lets you use it again by explaining a computer that once activated it has had LabVIEW uninstalled since then, or has be recycled.

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Re: Bug in LabVIEW 2018: wrong wiring when inserterting "delete from array" into an array wire

November 27, 2018, 6:41 am
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As with most insert operations on a wire, the resulting wiring depends on where the mouse was when you right-clicked. If your mouse is a few pixels below the array wire when you insert, the operations is correct. If it is above, the you get what you see. It is a matter of learning how to correctly place the mouse.

 

(But yes, here is only one possible logical insert operation, so the LabVIEW editor could be a bit smarter here ...)

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NI VirtualBench-8054 and its Labview Programming

November 27, 2018, 6:48 am
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Good Morning everyone:

I am starting to use VirtualBench VB-8054 and try to use its digital IO to control one of my EVM. The problems I met is

 

When I followed the "QUICK START GUIDE" of this VB-8054. it always show me an error window with error code -375934. Is anybody know what I need to do to fix this problems?

 

Another question is that I am going to use this VB-8054 to output 5-bit logic output through its DIO output. These output has to be dynamically updated every 10 uSec, I plan to use LabVIEW to program this VB-8054 to complete the above job. What I am wondering

 

(1)  Is any sample code doing the similar job in this forum? any entering point from this VB-8054 GUI?

(2)  Does that LabVIEW running on computer plus this VB-8054 can have the DIO output response fast enough to reach update rate every 10uSec? 

(3)  Any other suggestions about this VB-8054? since I am a new for VBench

Thanks!

 

Willy

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Re: Best Practice: Is it better to write to a front panel object via a Reference>Property Node combination, or directly via a Constant>Duplicate Terminal

November 27, 2018, 6:56 am
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Using property nodes in current gen LabVIEW (2018), generally involves a thread swap causing extra overhead.  When you are just writing a value to a control, and you can use local variables (duplicate terminals), but if you had something like a subVI and you wanted to change the value of a control from another VI then local variables (duplicate terminals) wouldn't be an option.

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getting data from a third party software

November 27, 2018, 6:57 am
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Hello guys,

 

Iam trying to extract two processes (voltage & Current) from an instrument "Cadex C8000 Battery Testing System" which interfaces with a third party software "Cadex BatteryLab v2.0.0.9" with LabVIEW.

--> The instrument does not have any interface to access neither of the two processes of interest

--> the communication protocol from the instrument to the "Battery lab" is not available

 

I initially tried to see if the "battery lab" sw was able to log to file or something but no joy.

I thought about having the user select and ROI initially and then somehow using vision functions try to decipher what are the pictures in number...  is this the only was about this at this point? has any one done something like this that can point me to possible solution?

 

if i make this "batteryLab" top most say by clicking on its title bar and then i press the up or down key I can scroll through the max number of rows (4) but ctrl+c after that does not put it on the clipboard again no joy.

 

Any help in this will be appreciated.

 

 

 

 

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Re: Completely Uninstall Labview and NI Software

November 27, 2018, 7:08 am
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Is this a joke? Hundreds of people would not come to complaing it this would work..

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Re: Best Practice: Is it better to write to a front panel object via a Reference>Property Node combination, or directly via a Constant>Duplicate Terminal

November 27, 2018, 7:08 am
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That's great info - I'll keep that in mind! Thank you Smiley Happy

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Re: having problem creating installer

November 27, 2018, 7:24 am
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hmmm may be, but i don't know how the dependencies can be add/ install to this PC. As both have same version of labview and i think i remember i install both the same way... 

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Re: Disable HTTP port for web server gives Error 363500 uninstalling/Installing the server

November 27, 2018, 7:25 am
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There is not really any code involved. So Í'll try to explain the steps.

1. Create a web service in a LabVIEW project with some simple web resource vi's

2. Create an Installer with the Application builder and only include the web server with additional installers:

        - NI LabVIEW Runtime 2016 f5
        - Microsoft Silverlight 5.1
        - NI System Web server 2017
        - NI Web-Based Configuration and Monitoring 16.0.

3. Run installer which automatically publish the web server.

4. Go to http://localhost:3582/ using internet explorer and disable HTTP and enable SSL port, reboot.

 

Now http is disabled and https works. However if unpublish/uninstall/install is used now when http disabled I get that error mentioned.

I have tried changing configurationfiles and more but haven't found an solution how to be able to uninstall the web server

without needing to go and enable http again and reboot and uninstall. Would like to skip doing this step everytime Smiley Happy

 

Best regards

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Re: Power Spectral Density amplitude is about 1e6 times larger than what it should be

November 27, 2018, 7:29 am
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Hi,

We seem to have a similar problem. We would like to generate the PSD of a sine signal. We notice that the frequency of the peak of the PSD seems correct but the value of the amplitude of this peak is far from what we expect for a sine. We notice that this amplitude changes when we change the number of samples of our sine.

We have also tried simulating a PSD by doing the autocorrelation + FFT on the sine and we have the same problem.

 

Please could you help us find a way to have a correct amplitude?

 

Thanks a lot

Ella

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Re: NI USB 8452 excessively long program execution time

November 27, 2018, 7:33 am
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回應： Confused about Power Spectral Density output amplitudes

November 27, 2018, 7:33 am
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Hi,

No we tried mcduff's suggestion but it didn't change anything. The problem is not linked to the units of the amplitude but the way it varies depending on the amount of samples of the sine signal.

We have tried using the autocorrelation and FFT VIs instead but we have the same problem (illustrated in the VI attached).

 

If you have any suggestions we would be very grateful,

Ella

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Re: getting data from a third party software

November 27, 2018, 7:43 am
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Hi,

 

I would go on like this:

1. Contact the Cadex Support, and asking for an API of the Battery Lab software. Maybe .net or .dll.

2. Reverse Engineering the tcp/ip communication. Wireshark is a good tool for that. I just would search for the voltage and current values in the answer from the device to the host computer.

 

Good Luck!

 

Regards, 

Kay 

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Re: the connection for the given session has been lost

November 27, 2018, 7:45 am
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Adding my experience for anyone encountering this problem. I wasn't able to close the visa session (gave me a different error). Clearing the buffer seemed to solve the problem though.

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