protected unsafe void EnableActionSetStateVariablePeriod()
        {
            iCallbackSetStateVariablePeriod = new CallbackSetStateVariablePeriod(DoSetStateVariablePeriod);
            IntPtr ptr = GCHandle.ToIntPtr(iGch);

            DvServiceLinnCoUkDiagnostics1EnableActionSetStateVariablePeriod(iHandle, iCallbackSetStateVariablePeriod, ptr);
        }
 static extern void DvServiceLinnCoUkDiagnostics1EnableActionSetStateVariablePeriod(uint aHandle, CallbackSetStateVariablePeriod aCallback, IntPtr aPtr);