How to use matlab compiled DLL in Labview ?

I have LV 8.5, and am unable to use a matlab compiled DLL in my LV code. I have tried the 'import' command, but it does not list any functions. However, it does not show any errors during its execution. The existing solutions/responses to this question do not work either. I would also like to know of a way to deal with mxArray datatype. What is its equivalent in C (or any other high-level language) ? How do I retrieve an array that is returned from the matlab dll ?

I'm assuming you have either Matlab installed or at the very least the Matlab Runtime, otherwise the DLL won't work. The "import" command relies on having a header file. Do you have one? You also need to make sure the DLL has been compiled so that it's compatible with LabVIEW. The most likely problem is name mangling, which also occurs when you try to compile a DLL written in C++. See this post, which contains links to useful posts.
The mxArray datatype is a special datatype which is actually a structure. It's complicated. Your best bet is to create a C DLL that acts as an intermediary between the Matlab DLL and LabVIEW. If you are able to, you can, instead, simply call the Matlab code directly using the Matlab script node.

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Norick,
afaik there is no tool which provides you the possibility to create something like an instrument driver for .NET assemblies.
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hope this helps,
NorbertMessage Edited by Norbert B on 02-21-2007 02:16 AM
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How to generate and use Matlab(R2007) .dll's in Labview

Is there a step-by-step example on how to generate and use Matlab(R2007) .dll's in Labview.
Our experimenal hardware is LabView-controlled and we want to pass
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Hi there,
I am relatively new to Labview and I need some help trying to program an old HP3488A switch/control unit using the Call Library Function Node. I would like to convert the existing VB6 code, which uses gpib-32.dll, into Labview. What I have done in the VB code is to call the ibdev function to set up the HP instrument. I would like to do the same in Labview. How would I even go about setting up the .dll files as I am revamping the existing code (running on a Pentium II computer) and trying to create an identical code in Labview (running on a Pentium III computer). Also, after I have set up the .dll files (done any system configurations if necessary), how do I actually implement this file in Labview?
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I actually tried that before. As the HP3488A switch instrument is very old and came out before IEEE488.2 got introduced, it still uses IEEE 488.1, or HPIB commands. When I try using MAX or even my Agilent IO Control, it shows that there is an instrument connect to GPIB address 10, but neither programs can auto-identify the instrument using the *IDN? query. Even so, I tried typing ID? in both programs and I got no data back from the instrument. I'm not too sure as to what the problem is since I always get "\n" back from the instrument's reply. I even tried changing the termination character enable to TRUE and I still got nothing back.
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How to use matlab codes in a stand alone application without matlab license?

Hi,
I am not an expert in programming and i don't know about C++, i have a program using matlab codes and now i want to transfer it to a computer without matlab license. I've read something about using DLL, but i think i have to know C++ programming to wrtie "WRAPPER" and add some lines to the program, now transformed in C++.
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Hello Amir,
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Do you know which one you have ?
Hope this helps
Message Edité par TiTou le 11-24-2006 06:38 PM
When my feet touch the ground each morning the devil thinks "bloody hell... He's up again!"
Attachments:
mlab.png ‏71 KB

How to use postlv user event in labview

Hi sir
I am sending data labwindow cvi dll call to labview,for that we need postlv user event.please any one knows to use postlv user evenet in labview.
Below will be the structureand i need to update in labview .
typedef struct
unsigned
uDSPIO,
// uDAQMode,
// bControllerActive,
bShutDown,
bPowerOn,
bPowerHi,
bPowerFault,
bSGIdle,
bSGHold,
uBitsIn,
uBitsOut,
uCycleCount,
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uBlockCount,
uLogChannels,
uCurrentMode,
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float
fSetPoint,
fDAQRate,
fRange[LOG_CHANNELS],
fReadout[LOG_CHANNELS],
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char
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Attachments:
GDSCallback.vi ‏12 KB

AThe fixed size arrays in your structure are inlined byt the C compiler. This means they are not an array pointer (and definitely never a LabVIEW array handle) but rather LOG_CHANNELS amount of unsigned ints and floats directly embedded in the structure. In LabVIEW terms this is most easily represented as a cluster with LOG_CHANNELS elements inside the main cluster.
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However I would personally rethink this strategy. This huge cluster monster is passed into PostLVUserEvent() each time and copied into the event data on every event, causing quite a bit of overhead that way. Is it really necessary to post all this data every time?
Also you have commented out uDAQMode and bControllerActive in your C structure but included it in the LabVIEW cluster which will certainly throw off your data. Last but not least the b prefix would probably indicate that you are only using that element as a boolean value, so why not consider to use bit fields there? In LabVIEW you can easily seperate those bitfields by either translating the resulting uInt32 into a boolean array or even more efficiently use boolean logic to detect the bits.
And in order to let LabVIEW react on a user event you have to create that user event with the correct datatype (your cluster monster) and then pass the user event refnum to your DLL. This DLL then calls PostLVUserEvent() with the user event refnum as first parameter and a pointer to a data structure that matches the LabVIEW user event datatype EXACTLY whenever it wants to post an event to LabVIEW. The user event is also registered in an event structure in LabVIEW which will then get triggered everytime your DLL posts an event by correctly calling PostLVUserEvent().
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

How to use a c file in LabVIEW

Hi All,
I have a c file which communicates through serial port and J1850 protocol. I want to use the C file in labview and do the communication through serial port.
Can any one give me an idea how I have to use the c file in LabVIEW.
Thank you.!
---------------- Be Good. Do Good. ---------------------

Have you tried reading the LabVIEW Help or even searching this web site? This question has been asked MANY times. There's a section in the LabVIEW Help called "Calling Code Written in Text-Based Programming Languages." There are also several articles written on this. Here's just one: https://decibel.ni.com/content/docs/DOC-1690
Please do the research and then come back with a more specific question.

How To Use Exported Function "CallInstrument" of LabView.exe ?

Hello!
I want to use the function "CallInstrument" to dynamically call VIs with LabView. Did anyone has experiences with this function?
All I kow is following:
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Its prototype is maybe:
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( CPStr Type is a StringArray of PStr (Short PascalStrings) as it is used by LabView to store Path datatypes. )
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Dear Rolf Kalbermatter,
Thirst, thanks a lot for your answer! -
You sure right, It whould be much much more comfortable to use the VI Server.
And you're also right... using a undocumented dll-function is absolutly no longtime solution.
Currently I am using VI Server for my problem, but it doesn't fit my interesst so much.
But I will explain, what I'm trying to do.
I want to call a VI dynamically from LabView, giving Parameters to its Controls and receive Results from its Indicators.
Realy no big job, but VI Server only let you do this that easy if you have a VI Typedef. otherwise... with untyped VIs, its not that simple. Ok.. its not impossible, you can use "GetAllControlValues" and "SetControlValue" (functions from VI server) and the call "RunVi". But this can get slow (>100ms per call :/ )
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Then i tried to make use of "Call2" from within LabView, and it took me some time to find out the right Parametersyntax but finnaly i got it and it worked fine ... but it was no long time until problems occur. I cannot tell what really went wrong, but sometimes labview simply crashed or hang into a loop reseting some VIs. And its also impossible to stop a running vi, with has made a call to "Call2", if the call doesn't return by itself.
Next step is/was trying to take advantage of CallInstrument. So, yesterday... after hours of analysing assemblercode, i finnally found out the correct use of LabView.exe->CallInstrument and i'm very impressed about its speed (0-15ms per call). The prototype seem to be the same as you explained in your reply int CallInstrument(Path path, Bool modal, int32 nInputs, int32 nOutputs, ...)
But It has the same problem as its ActiveX derivat "Call2".. if you call an endless looping VI, LabView cannot stop your caller-vi. The other bad thing is, that this function is using dynamic paramterlist, which are placed directly onto the stack!
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(continued with next answer)

How to use a C# dll with JNI

After a ton of issues, I finally got this working properly. I've come across a lot of forum posts about the various problems and VERY few answers so I thought I would post my solution here.
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Hi,
i have to use a c# dll in my java program .by following this link http://www.codeproject.com/KB/cross-platform/javacsharp.aspx i done that.but it is working for only one c# program.if i am trying to use a dll it is throwing error
# An unexpected error has been detected by Java Runtime Environment:
# Internal Error (0xe0434f4d), pid=3988, tid=3704
# Java VM: Java HotSpot(TM) Client VM (11.0-b16 mixed mode, sharing windows-x86)
# Problematic frame:
# C [kernel32.dll+0x442eb]
# An error report file with more information is saved as:
# D:\Work\EclipseWorkspace\HelloInflux\hs_err_pid3988.log
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
Please help me out. i want a few steps to invoke a c# dll by using jni

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Hallöchen!
I try to use a function from a cygwin DLL in a LabVIEW 7.0 VI. So
I wrote
void funcName(double values[], long number_values)
for (int i=0; i < number_values; i++) values[i] /= 2.0;
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Tschö,
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Torsten Bronger, aquisgrana, europa
vetus

Hallöchen!
LarsRoe writes:
> [...] LabVIEW arrays have a different structure than the
> traditional C arrays. As a quick test, try passing in a single
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> argument.
Even a "void Test()" lets LabVIEW crash. I now say
extern "C" {
void Test();
void Test() {
return;
> The prototype in your C function needs to match the prototype you
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Tschö,
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Torsten Bronger, aquisgrana, europa vetus

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