diff --git a/CMS_CORE_Library/S7Net/Nc_S7Net.cs b/CMS_CORE_Library/S7Net/Nc_S7Net.cs
index f49500c..cf7e9f4 100644
--- a/CMS_CORE_Library/S7Net/Nc_S7Net.cs
+++ b/CMS_CORE_Library/S7Net/Nc_S7Net.cs
@@ -72,7 +72,7 @@ namespace CMS_CORE_Library.S7Net
         /// <summary>
         /// Lock per connessione PLC
         /// </summary>
-        private readonly object connectLock = new object();
+        private readonly static object connectLock = new object();
 
         #endregion