diff --git a/dotnet/IEC61850forCSharp/IEC61850CommonAPI.cs b/dotnet/IEC61850forCSharp/IEC61850CommonAPI.cs
index 19acd559..18f1aa8c 100644
--- a/dotnet/IEC61850forCSharp/IEC61850CommonAPI.cs
+++ b/dotnet/IEC61850forCSharp/IEC61850CommonAPI.cs
@@ -173,6 +173,87 @@ namespace IEC61850
 			QUESTIONABLE = 3
 		}
 
+		/// <summary>
+		/// MmsError values
+		/// </summary>
+		public enum MmsError
+		{
+			/* generic error codes */
+			MMS_ERROR_NONE = 0,
+			MMS_ERROR_CONNECTION_REJECTED = 1,
+			MMS_ERROR_CONNECTION_LOST = 2,
+			MMS_ERROR_SERVICE_TIMEOUT = 3,
+			MMS_ERROR_PARSING_RESPONSE = 4,
+			MMS_ERROR_HARDWARE_FAULT = 5,
+			MMS_ERROR_CONCLUDE_REJECTED = 6,
+			MMS_ERROR_INVALID_ARGUMENTS = 7,
+			MMS_ERROR_OUTSTANDING_CALL_LIMIT = 8,
+
+			MMS_ERROR_OTHER = 9,
+
+			/* confirmed error PDU codes */
+			MMS_ERROR_VMDSTATE_OTHER = 10,
+
+			MMS_ERROR_APPLICATION_REFERENCE_OTHER = 20,
+
+			MMS_ERROR_DEFINITION_OTHER = 30,
+			MMS_ERROR_DEFINITION_INVALID_ADDRESS = 31,
+			MMS_ERROR_DEFINITION_TYPE_UNSUPPORTED = 32,
+			MMS_ERROR_DEFINITION_TYPE_INCONSISTENT = 33,
+			MMS_ERROR_DEFINITION_OBJECT_UNDEFINED = 34,
+			MMS_ERROR_DEFINITION_OBJECT_EXISTS = 35,
+			MMS_ERROR_DEFINITION_OBJECT_ATTRIBUTE_INCONSISTENT = 36,
+
+			MMS_ERROR_RESOURCE_OTHER = 40,
+			MMS_ERROR_RESOURCE_CAPABILITY_UNAVAILABLE = 41,
+
+			MMS_ERROR_SERVICE_OTHER = 50,
+			MMS_ERROR_SERVICE_OBJECT_CONSTRAINT_CONFLICT = 55,
+
+			MMS_ERROR_SERVICE_PREEMPT_OTHER = 60,
+
+			MMS_ERROR_TIME_RESOLUTION_OTHER = 70,
+
+			MMS_ERROR_ACCESS_OTHER = 80,
+			MMS_ERROR_ACCESS_OBJECT_NON_EXISTENT = 81,
+			MMS_ERROR_ACCESS_OBJECT_ACCESS_UNSUPPORTED = 82,
+			MMS_ERROR_ACCESS_OBJECT_ACCESS_DENIED = 83,
+			MMS_ERROR_ACCESS_OBJECT_INVALIDATED = 84,
+			MMS_ERROR_ACCESS_OBJECT_VALUE_INVALID = 85, /* for DataAccessError 11 */
+			MMS_ERROR_ACCESS_TEMPORARILY_UNAVAILABLE = 86, /* for DataAccessError 2 */
+
+			MMS_ERROR_FILE_OTHER = 90,
+			MMS_ERROR_FILE_FILENAME_AMBIGUOUS = 91,
+			MMS_ERROR_FILE_FILE_BUSY = 92,
+			MMS_ERROR_FILE_FILENAME_SYNTAX_ERROR = 93,
+			MMS_ERROR_FILE_CONTENT_TYPE_INVALID = 94,
+			MMS_ERROR_FILE_POSITION_INVALID = 95,
+			MMS_ERROR_FILE_FILE_ACCESS_DENIED = 96,
+			MMS_ERROR_FILE_FILE_NON_EXISTENT = 97,
+			MMS_ERROR_FILE_DUPLICATE_FILENAME = 98,
+			MMS_ERROR_FILE_INSUFFICIENT_SPACE_IN_FILESTORE = 99,
+
+			/* reject codes */
+			MMS_ERROR_REJECT_OTHER = 100,
+			MMS_ERROR_REJECT_UNKNOWN_PDU_TYPE = 101,
+			MMS_ERROR_REJECT_INVALID_PDU = 102,
+			MMS_ERROR_REJECT_UNRECOGNIZED_SERVICE = 103,
+			MMS_ERROR_REJECT_UNRECOGNIZED_MODIFIER = 104,
+			MMS_ERROR_REJECT_REQUEST_INVALID_ARGUMENT = 105
+		}
+
+		/// <summary>
+		/// MmsFileServiceType values
+		/// </summary>
+		public enum MmsFileServiceType
+		{
+			MMS_FILE_ACCESS_TYPE_READ_DIRECTORY = 0,
+			MMS_FILE_ACCESS_TYPE_OPEN = 1,
+			MMS_FILE_ACCESS_TYPE_OBTAIN = 2,
+			MMS_FILE_ACCESS_TYPE_DELETE = 3,
+			MMS_FILE_ACCESS_TYPE_RENAME = 4
+		}
+
 		/// <summary>
 		/// The quality of a data object.
 		/// </summary>
diff --git a/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs b/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs
index efff22ef..f7059787 100644
--- a/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs
+++ b/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs
@@ -659,6 +659,23 @@ namespace IEC61850
 			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
 			static extern void IedServer_setConnectionIndicationHandler(IntPtr self, InternalConnectionHandler handler, IntPtr parameter);
 
+			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+			static extern IntPtr IedServer_getMmsServer(IntPtr self);
+
+			public delegate MmsError FileAccessHandler(object parameter, ClientConnection clientConnection, MmsFileServiceType service, string localFilename, string otherFilename);
+
+			private FileAccessHandler mmsFileAccessHandler = null;
+			private object mmsFileAccessHandlerParameter = null;
+
+			[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+			private delegate int InternalMmsFileAccessHandler (IntPtr parameter, IntPtr connection, int service, [MarshalAs(UnmanagedType.LPStr)] string localFilename, [MarshalAs(UnmanagedType.LPStr)] string otherFilename);
+
+			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+			static extern void MmsServer_installFileAccessHandler(IntPtr self, InternalMmsFileAccessHandler handler, IntPtr parameter);
+
+			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+			static extern void MmsServer_setFilestoreBasepath(IntPtr self, [MarshalAs(UnmanagedType.LPStr)] string basepath);
+
 			private IntPtr self = IntPtr.Zero;
 
 			private InternalControlHandler internalControlHandlerRef = null;
@@ -787,6 +804,15 @@ namespace IEC61850
 
 			private Dictionary<IntPtr, ClientConnection> clientConnections = new Dictionary<IntPtr, ClientConnection> ();
 
+			int fileAccessHandler (IntPtr parameter, IntPtr connection, int service, string localFilename, string otherFilename)
+			{
+				ClientConnection con = null;
+
+				clientConnections.TryGetValue(connection, out con);
+
+				return (int) mmsFileAccessHandler (mmsFileAccessHandlerParameter, con, (MmsFileServiceType) service, localFilename, otherFilename);
+			}
+
 
 
 			public IedServer(IedModel iedModel, IedServerConfig config = null)
@@ -823,6 +849,7 @@ namespace IEC61850
 			//}
 
 			private InternalConnectionHandler internalConnectionHandler = null;
+			private InternalMmsFileAccessHandler internalMmsFileAccessHandler = null;
 
 			/// <summary>
 			/// Sets the local ip address for listening
@@ -940,7 +967,20 @@ namespace IEC61850
 
 				IedServer_setWaitForExecutionHandler(self, controlObject.self, internalControlWaitForExecutionHandlerRef, GCHandle.ToIntPtr(info.handle));
 			}
-				
+
+			public void SetFileAccessHandler (FileAccessHandler handler, object parameter)
+			{
+				mmsFileAccessHandler = handler;
+				mmsFileAccessHandlerParameter = parameter;
+
+				if (internalMmsFileAccessHandler == null)
+					internalMmsFileAccessHandler = new InternalMmsFileAccessHandler (fileAccessHandler);
+
+				IntPtr mmsServer = IedServer_getMmsServer(self);
+
+				MmsServer_installFileAccessHandler(mmsServer, internalMmsFileAccessHandler, IntPtr.Zero);
+			}
+
 			public void HandleWriteAccess (DataAttribute dataAttr, WriteAccessHandler handler, object parameter)
 			{
 				writeAccessHandlers.Add (dataAttr.self, new WriteAccessHandlerInfo(handler, parameter, dataAttr));
@@ -953,6 +993,13 @@ namespace IEC61850
 			{
 				IedServer_setWriteAccessPolicy (self, fc, policy);
 			}
+
+			public void SetFilestoreBasepath(string basepath)
+			{
+				IntPtr mmsServer = IedServer_getMmsServer(self);
+
+				MmsServer_setFilestoreBasepath(mmsServer, basepath);
+			}
 		
 
 			public void LockDataModel()