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Controlling LabVIEW from Microsoft Excel or Access

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Hello everyone,

 

I want to control the LabVIEW application from MS Access. But before that I would like to make it work in MS Excel. Once it works with MS Excel it should work with MS Access too.

 

The task is: I press a button in MS Excel and it should go to the LabVIEW application and read the data and send it back to Excel. In the next step I also want to send data to LabVIEW via a similar or same button from Excel.

 

I am trying to do it with ActiveX. I created a simple LabVIEW application of Blink_led and I am trying to get the value of 'millisecond to wait' control from LabVIEW. I have attached the LV file.

 

I also created a ActiveX button in Excel and wrote a small VBA code. The snippet of the VBA code and the Excel is attached.

 

My problem is that when I click the button in Excel,I get an error '80040154' saying Class not recognised. The error points to line 'Set lvapp = CreateObject("Blinky.Application")'. I have added the .tlb library file of the applicaiton in Tools>References in VBA editor. I have searched through google for the error but could not find a suitable working solution.

 

Can anyone please help in resolving the issue? Or can you suggest any way by which I can complete my task?

 

P.S. - I am new to ActiveX.

 

I am working with LV 2014 and MS Office Professional Plus 2010.

 

Thank you in advance.

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Message 1 of 9
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If you have the Report Generation Toolkit, it should be relatively straight-forward to let LabVIEW "drive" Excel, but to have Excel be the "driver" is, I believe, considerably more difficult.

 

Bob Schor

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Message 2 of 9
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Hello Bob,

 

Thank you for your reply. I have the Report Generation Toolkit. I have even tried it out and it works perfectly fine.

 

But as I mentioned earlier,at a later stage I want to control LabVIEW from MS Access. I know that data can be communicated with the Report Generation Toolkit with MS Access as well. But there is an issue in that too. The database format which I have in MS Access is (.adp) format, which is no longer supported. Also, with the Report Generation Toolkit I could not exchange the data because of this format.

 

So, I am trying with ActiveX communication so that it does not depend on the format of the database files.

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Message 3 of 9
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If you do a Web Search for LabVIEW Sql, you will find NI Software that says it can connect to Sql and to Access.  If you, instead, search for LabVIEW Sqlite, you should find James Powell's excellent Video about LAVA's SQLite Library for LabVIEW.

 

Again, both these methods involve LabVIEW being the "controller", that is, reading and writing databases that are compatible with Access, SQL, or SQLite, not directly interacting with those programs.

 

Bob Schor

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Message 4 of 9
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We need to understand why you want Excel/Access be the driver and not LabVIEW. From your earlier posts, it's not clear...at least to me.

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Message 5 of 9
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Hello Eric1977,

 

Basically, I want to automate a test sequence which runs in LabVIEW. At present, test results data is stored manually in MS Access database. So, I do not want to make changes in the exisiting LabVIEW application which is used for testing. I want to acquire the data directly from MS Access application with help of a button or any control.

 

So, when I press the button in MS Access, it should go to the LabVIEW application, run the code there and send the values back to MS Access and get filled in the respective column of the MS Access table.

 

Sorry if it is too confusing. I am trying my best to explain the situation.

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Hello Bob,

 

I want to avoid tampering with the SQL directly. As, if by any chance it goes wrong anytime, it might affect the whole SQL database.

 

As I explained earlier, it will be best if I can acquire the data from MS Access without touching the LabVIEW application physically.

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Message 7 of 9
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That seems very backwards. Why not just enhance the program to do everything in the LabVIEW app and, when done, save the data to the MS Access application?

 

The only way I could even think of doing this is through either a UDP or TCPIP connection which I don't know of any VBA code that handles that. Anyway, you'd need to get into the LV app and modify that & at that point, I'd just do everything inside the LV app.

 

Seems like more trouble than it's worth.

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Message 8 of 9
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Solution
Accepted by topic author E.R.

Hello everyone,

 

Thank you for your time and responses.

 

I wanted to control LabVIEW from MS Access, because the LV application was already developed and is already in use. So I did not want to tamper anyting in the LV application. Secondly as I mentioned earlier, the format of my MS Access database file is (.adp), which is no longer supported and is not accesseble from LV.

 

Anyways, I managed to do my task and it works really awesome. I am mentioning the steps which I followed:

 

Steps to control LabVIEW (as server) from MS Access (as client) via ActiveX

 

  1. Create an application file (.exe) of the project. While creating the application file, make sure to select the field ‘Enable ActiveX server’ under Advanced section. This will create a Type library file (.tlb) in the application folder.
  2. Run the application (.exe) as an administrator once.
  3. Create a button in MS Access / MS Excel.
  4. Open VBA editor in MS Access / MS Excel.
  5. Add .tlb file to the References.
    1. Tools > References > Browse to the application folder and find the .tlb file
  1. Write the VBA code and execute (Basic starting sample shown below).
    Spoiler

    Dim lvapp As Blinky.Application

    Dim vi As Blinky.VirtualInstrument

    Dim viPath

       

    Set lvapp = CreateObject("Blinky.Application")

    viPath=".................\builds\Blinky\Blinky.exe\Blink_led.vi "

    Set vi = lvapp.GetVIReference(viPath)   'Load the vi into memory

     

    Call vi.SetControlValue("stop", False)

    Call vi.SetControlValue("Boolean", True)

    Call vi.SetControlValue("milliseconds to wait", 500)

     

    'Wait for 10s

    T0 = Timer

    Do

            Delay = Timer - T0

            E = vi.GetControlValue("Boolean 2")

            f = vi.GetControlValue("milliseconds to wait")

            Text3 = E

            Text1 = f

    Loop Until Delay = 10 'Change this value to pause time in second

     

    'Stop the VI

     Call vi.SetControlValue("Boolean", False)

     Call vi.SetControlValue("stop", True)

       

     E = vi.GetControlValue("Boolean 2")

     f = vi.GetControlValue("milliseconds to wait")

           

     Text3 = E

     Text1 = f

       

     'Wait for 1s

     T0 = Timer

     Do

            Delay = Timer - T0

     Loop Until Delay = 1 'Change this value to pause time in second

       

     'Close the application

     lvapp.Quit

 

 

I hope someone finds this useful in their future projects.

 

Thank you all once again.

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