Opc.Ua.Server.SamplingGroupManager.ModifyMonitoredItem C# (CSharp) Method

        public virtual ServiceResult ModifyMonitoredItem(
            OperationContext           context,
            TimestampsToReturn         timestampsToReturn,
            ISampledDataChangeMonitoredItem   monitoredItem,
            MonitoredItemModifyRequest itemToModify,
            Range                      range)
        {   
            // use existing interval as sampling interval.
            double samplingInterval = itemToModify.RequestedParameters.SamplingInterval;

            if (samplingInterval < 0)
            {
                samplingInterval = monitoredItem.SamplingInterval;
            }
            
            // limit the sampling interval.
            double minimumSamplingInterval = monitoredItem.MinimumSamplingInterval;

            if (minimumSamplingInterval > 0 && samplingInterval < minimumSamplingInterval)
            {
                samplingInterval = minimumSamplingInterval;
            }
            
            // calculate queue size.
            uint queueSize = itemToModify.RequestedParameters.QueueSize;

            if (queueSize == 0)
            {
                queueSize = monitoredItem.QueueSize;
            }
        
            if (queueSize > m_maxQueueSize)
            {
                queueSize = m_maxQueueSize;
            }            

            // get filter.
            MonitoringFilter filter = null;

            if (!ExtensionObject.IsNull(itemToModify.RequestedParameters.Filter))
            {
                filter = (MonitoringFilter)itemToModify.RequestedParameters.Filter.Body;               
            }

            // update limits for event filters.
            if (filter is EventFilter)
            {
                samplingInterval = 0;
            }
            
            // modify the item attributes.
            ServiceResult error = monitoredItem.ModifyAttributes(
                context.DiagnosticsMask,
                timestampsToReturn,
                itemToModify.RequestedParameters.ClientHandle,
                filter,
                filter,
                range,
                samplingInterval,
                queueSize,
                itemToModify.RequestedParameters.DiscardOldest);

            // state of item did not change if an error returned here.
            if (ServiceResult.IsBad(error))
            {
                return error;
            }

            // update sampling.
            ModifyMonitoring(context, monitoredItem);

            // everything is ok.
            return ServiceResult.Good;
        }