diff --git a/SCADA/Program/ModbusDriver/ModbusRTUDriver.cs b/SCADA/Program/ModbusDriver/ModbusRTUDriver.cs
index 8722334..d03f705 100644
--- a/SCADA/Program/ModbusDriver/ModbusRTUDriver.cs
+++ b/SCADA/Program/ModbusDriver/ModbusRTUDriver.cs
@@ -43,7 +43,7 @@ namespace ModbusDriver
         {
             get
             {
-                return _serialPort == null ? false : _serialPort.IsOpen == false;
+                return _serialPort == null || _serialPort.IsOpen == false;
             }
         }
 
diff --git a/SCADA/dll/ModbusDriver.dll b/SCADA/dll/ModbusDriver.dll
index af42fe4..cb5ab11 100644
Binary files a/SCADA/dll/ModbusDriver.dll and b/SCADA/dll/ModbusDriver.dll differ