diff --git a/MECF.Framework.Common/Aitex/Core/RT/DataCenter/DataManager.cs b/MECF.Framework.Common/Aitex/Core/RT/DataCenter/DataManager.cs
index ab35108..9ff4214 100644
--- a/MECF.Framework.Common/Aitex/Core/RT/DataCenter/DataManager.cs
+++ b/MECF.Framework.Common/Aitex/Core/RT/DataCenter/DataManager.cs
@@ -224,8 +224,10 @@ namespace Aitex.Core.RT.DataCenter
 		}
 
 		public object Poll(string key)
-		{
-			return _keyValueMap.ContainsKey(key) ? _keyValueMap[key].Value : null;
+        {
+            if (string.IsNullOrEmpty(key))
+                return null;
+			return _keyValueMap.TryGetValue(key, out var item) ? item.Value : null;
 		}
 
 		public void Traverse(object instance, string keyPrefix)