fix modbusRTU

SCADA/Program/ModbusDriver/ModbusDriver.sln

@@ -1,32 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 11.00
-# Visual Studio 2010
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ModbusDriver", "ModbusDriver.csproj", "{AEA44301-6A29-4AF7-91E8-E6D755B618F1}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Debug|Itanium = Debug|Itanium
-		Debug|x64 = Debug|x64
-		Release|Any CPU = Release|Any CPU
-		Release|Itanium = Release|Itanium
-		Release|x64 = Release|x64
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Debug|Itanium.ActiveCfg = Debug|Itanium
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Debug|Itanium.Build.0 = Debug|Itanium
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Debug|x64.ActiveCfg = Debug|x64
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Debug|x64.Build.0 = Debug|x64
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Release|Any CPU.Build.0 = Release|Any CPU
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Release|Itanium.ActiveCfg = Release|Itanium
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Release|Itanium.Build.0 = Release|Itanium
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Release|x64.ActiveCfg = Release|x64
-		{AEA44301-6A29-4AF7-91E8-E6D755B618F1}.Release|x64.Build.0 = Release|x64
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-EndGlobal

SCADA/Program/ModbusDriver/ModbusRTUDriver.cs

@@ -319,17 +319,20 @@ namespace ModbusDriver
         #endregion
 
         #region :IReaderWriter 
+        object _async = new object();
         public byte[] ReadBytes(DeviceAddress address, ushort size)
         {
             int area = address.Area;
-            try
+
-            {
             //no need to multiply by 16
             //byte[] header = area == Modbus.fctReadCoil ? CreateReadHeader(address.Start * 16, (ushort)(16 * size), (byte)area) :
             // CreateReadHeader(address.Start, size, (byte)area);
             byte[] header = CreateReadHeader(address.Start, size, (byte)area);
+            lock (_async)
+            {
+                try
+                {
                     _serialPort.Write(header, 0, header.Length);
-
                     /* different function_code have different realy frameBytes 
                     *  function_code 1/2: one register variable use one bit
                     *  function_code 3/4: one register variable use two bytes
@@ -368,6 +371,7 @@ namespace ModbusDriver
                     return null;
                 }
             }
+        }
 
         public ItemData<int> ReadInt32(DeviceAddress address)
         {