protected unsafe void EnableActionEcho()
        {
            iCallbackEcho = new CallbackEcho(DoEcho);
            IntPtr ptr = GCHandle.ToIntPtr(iGch);

            DvServiceLinnCoUkDiagnostics1EnableActionEcho(iHandle, iCallbackEcho, ptr);
        }
 static extern void DvServiceLinnCoUkDiagnostics1EnableActionEcho(uint aHandle, CallbackEcho aCallback, IntPtr aPtr);