private static string GetStateError(ExceptionStateError stateError)
 {
     switch (stateError)
     {
         case ExceptionStateError.ServiceNotAllowed:
             return "Service not allowed";
         case ExceptionStateError.ServiceUnknown:
             return "Service unknown";
     }
     return string.Empty;
 }
 /// <summary>
 /// Constructor for AARE error.
 /// </summary>
 internal GXDLMSException(ExceptionStateError stateError, ExceptionServiceError serviceError)
     : base("Meter returns " + GetStateError(stateError) + " exception. " + GetServiceError(serviceError))
 {
     StateError = stateError;
     ExceptionServiceError = serviceError;
 }