diff --git a/MECF.Framework.RT.Core/Managers/PDS/ProcessDataStatCounter.cs b/MECF.Framework.RT.Core/Managers/PDS/ProcessDataStatCounter.cs
index 18ac62c..55e5c9e 100644
--- a/MECF.Framework.RT.Core/Managers/PDS/ProcessDataStatCounter.cs
+++ b/MECF.Framework.RT.Core/Managers/PDS/ProcessDataStatCounter.cs
@@ -17,6 +17,7 @@ namespace MECF.Framework.RT.Core.Managers.PDS
         private DateTime _lastPollingTime = DateTime.MinValue;
         private readonly R_TRIG _trigDataPollingError = new();
         private FunFilter _dataFilter;
+        private readonly R_TRIG _rTrigPollDataFailed = new();
 
         #endregion
 
@@ -94,7 +95,15 @@ namespace MECF.Framework.RT.Core.Managers.PDS
             var sum = 0.0d;
             foreach (var pdata in DataPath)
             {
-                var sFlow = DATA.Poll(pdata).ToString();
+                var polled = DATA.Poll(pdata);
+                _rTrigPollDataFailed.CLK = polled == null;
+                if(_trigDataPollingError.Q)
+                    LOG.Error($"Failed to count {pdata}, unable to poll data from RT");
+                
+                if (polled == null)
+                    continue;
+                    
+                var sFlow = polled.ToString();
                 if (double.TryParse(sFlow, out var dFlow))
                 {
                     sum += dFlow * ts.TotalSeconds;
diff --git a/MECF.Framework.RT.EquipmentLibrary/HardwareUnits/GasFlow/GasFlowUnit.cs b/MECF.Framework.RT.EquipmentLibrary/HardwareUnits/GasFlow/GasFlowUnit.cs
index c1d7a6e..8ceaf9a 100644
--- a/MECF.Framework.RT.EquipmentLibrary/HardwareUnits/GasFlow/GasFlowUnit.cs
+++ b/MECF.Framework.RT.EquipmentLibrary/HardwareUnits/GasFlow/GasFlowUnit.cs
@@ -55,8 +55,8 @@ namespace MECF.Framework.RT.EquipmentLibrary.HardwareUnits.GasFlow
         public void Initialize(string moduleName)
         {
             ModuleName = moduleName;
-            SC.RegisterValueChangedCallback($"PM.{ModuleName}.Efficiency.{GasFlowRatioName}", (o) => { Set_Callback(o.ToString()); });
-            GasFlowRatioValue = SC.GetValue<double>($"PM.{ModuleName}.Efficiency.{GasFlowRatioName}");
+            SC.RegisterValueChangedCallback($"PM.{ModuleName}.Efficiency.{GasFlowRatioName}", OnGasFlowRatioSCChanged);
+            GasFlowRatioValue = SC.SafeGetValue<double>($"PM.{ModuleName}.Efficiency.{GasFlowRatioName}", 1d);
 
             if (GasName == "PN2_Vent")
                 DATA.Subscribe($"{ModuleName}.GasRealTimeFlow.{GasName}.FeedBackSpecial", () => PN2_VentSpecial, SubscriptionAttribute.FLAG.IgnoreSaveDB);//仅作为显示用，不存储数据库
@@ -67,9 +67,12 @@ namespace MECF.Framework.RT.EquipmentLibrary.HardwareUnits.GasFlow
                 row.Initialize(moduleName, GasName);
         }
 
-        public void Set_Callback(string str = "")
+        private void OnGasFlowRatioSCChanged(object value)
         {
-            GasFlowRatioValue = SC.GetValue<double>($"PM.{ModuleName}.Efficiency.{GasFlowRatioName}");
+            if (value is double ratio)
+                GasFlowRatioValue = ratio;
+            else
+                GasFlowRatioValue = 1d;
         }
 
         public double GetGasFlowFeedBack()