Hi Andrey,

Thanks for your post here on the forums!

If you check the sample codes provided with OpticStudio in the ZOS-API Syntax help, or the boilerplate code, you can see that the python codes start as the following:

class PythonStandaloneApplication1(object):

    class LicenseException(Exception):

        pass

    class ConnectionException(Exception):

        pass

    class InitializationException(Exception):

        pass

    class SystemNotPresentException(Exception):

        pass

    def __init__(self, path=None):

        # determine location of ZOSAPI_NetHelper.dll & add as reference

        aKey = winreg.OpenKey(winreg.ConnectRegistry(None, winreg.HKEY_CURRENT_USER), r'Software\Zemax', 0, winreg.KEY_READ)

        zemaxData = winreg.QueryValueEx(aKey, 'ZemaxRoot')

        NetHelper = os.path.join(os.sep, zemaxData[0], r'ZOS-API\Libraries\ZOSAPI_NetHelper.dll')

        winreg.CloseKey(aKey)

        clr.AddReference(NetHelper)

        import ZOSAPI_NetHelper

        

        # Find the installed version of OpticStudio

        #if len(path) == 0:

        if path is None:

            isInitialized = ZOSAPI_NetHelper.ZOSAPI_Initializer.Initialize()

        else:

            # Note -- uncomment the following line to use a custom initialization path

            isInitialized = ZOSAPI_NetHelper.ZOSAPI_Initializer.Initialize(path)

        

        # determine the ZOS root directory

        if isInitialized:

            dir = ZOSAPI_NetHelper.ZOSAPI_Initializer.GetZemaxDirectory()

        else:

            raise PythonStandaloneApplication1.InitializationException('Unable to locate Zemax OpticStudio.  Try using a hard-coded path.')

In the above section, there are two ways for the initialization, one without any given path, in which case the default path is used, and a second one with a given path, in which case the API code searches for OpticStudio at that specifc given location. 

If you would like to run a specific version of OpticStudio, you can customize the initialization with the path where the specific version of OpticStudio that you would like to run is installed.

I hope this helps, but if you have any further questions, please let us know and we will be happy to help!

Best,

Csilla