installation_procedure.md

June 3, 2020 ยท View on GitHub

API Installation Procedure

The provided API is in the form of a windows dynamic link library (dll). The helper header file listing the functions in the dll is provided (please see the 'support' folder)

The following software/packages are needed for installing API on your PC.

  1. VC++ redistributable x64 located here [https://support.microsoft.com/en-gb/help/2977003/the-latest-supported-visual-c-downloads]
  2. Armadillo package located here - [http://arma.sourceforge.net/download.html] Please use the version '9.500.2'. This is the only version that is useable. The BLAS and LAPACK precompiled binaries provided by Armadillo are being used by the DLL.

Procedure

  • Install the VC++ redistributable.
  • Create the following directory structure - C:\cpp_libraries\math_libraries
  • Place the unzipped Armadillo folder inside the above directory. The directory structure should look like this - C:\cpp_libraries\math_libraries\armadillo-9.500.2
  • Go to the ..\armadillo-9.500.2\examples folder
  • Cut the lib_win64 and place it directly under the armadillo-9.500.2 folder. The final structure should look like this - C:\cpp_libraries\math_libraries\armadillo-9.500.2\lib_win64

figure 1. Armadillo library placement - final structure

Testing the Installation

Download the api_installation_test.vi file from the support folder. Open the block diagram and go to the Call library node function. Double click on it and link the AOL_functions.dll from your local drive correctly.

figure 2. API function call - api_installation_test.vi (LabVIEW)

Note: The AOL_functions.dll file can be located anywhere on the PC. However a shallow directory on the root (C:) drive is preferable. If the AOL_functions.h header file is needed, it should be placed next to the AOL_functions.dll file.

The api_installation_test.vi simply takes in a sample 2D array and doubles it. Run the VI and verify that this is happening. On a successful run, you should see the following -

  1. The output_array element values should be double the input_array element values. This verifies that Armadillo and the underlying BLAS and LAPACK libraries are being called correctly.

  2. return should be equal to 3. This ensures that the function has run without any internal errors.

  3. API Exec time (ms) should ideally be less than 5 ms. However, should certainly not be consistently in 10s of ms or more. This will verify that anti-virus or any other internal windows process is not blocking the API.

figure 3. api_installation_test.vi front panel depicting successful installation

If you see any error popping up or errors appearing in error out indicator, note the error code and check on the National Instruments website. Also ensure that the installation process is followed correctly.

>> API core functions details.