Cannot script a powershell or command line FAST inventory using DPM 2012

I am trying to script a FAST INVENTORY for our DPM 2012 server using the documented powershell command

    PS C:\>$DPMLib = Get-DPMLibrary -DPMServerName "TestingServer"
    Start-DPMLibraryInventory -DPMLibrary $DPMLib -FastInventory

I get the following error on our "Firestreamer Media Changer-2" library

Start-DPMLibraryInventory : Cannot convert 'System.Object[]' to the type 'Micro
soft.Internal.EnterpriseStorage.Dls.UI.ObjectModel.LibraryManagement.Library' r
equired by parameter 'DPMLibrary'. Specified method is not supported.
At line:1 char:38
+ Start-DPMLibraryInventory -DPMLibrary <<<<  $DPMLib -FastInventory
    + CategoryInfo          : InvalidArgument: (:) [Start-DPMLibraryInventory]
   , ParameterBindingException
    + FullyQualifiedErrorId : CannotConvertArgument,Microsoft.Internal.Enterpr
   iseStorage.Dls.UI.Cmdlet.StartInventory

Once this is fixed I would like to run the Fast Inventory from a .bat file and then schedule it?
I am unable to do this task as the DPM2012 Management Shell does not appear to be associated with the standard powershell

Thx,
Joe

Thx, Joe