diff --git a/dotnet/IEC61850forCSharp/Control.cs b/dotnet/IEC61850forCSharp/Control.cs
index 4fa909cf..c096c923 100644
--- a/dotnet/IEC61850forCSharp/Control.cs
+++ b/dotnet/IEC61850forCSharp/Control.cs
@@ -28,10 +28,7 @@ using IEC61850.Common;
 
 namespace IEC61850
 {
-
-    /// <summary>
-    /// IEC 61850 common API parts (used by client and server API)
-    /// </summary>
+    // IEC 61850 common API parts (used by client and server API)
 	namespace Common {
 
         /// <summary>
@@ -76,8 +73,8 @@ namespace IEC61850
         }
 	}
 
-	namespace Client {
-
+	namespace Client
+    {
 		[StructLayout(LayoutKind.Sequential)]
 		internal struct LastApplErrorInternal
 		{
@@ -128,7 +125,10 @@ namespace IEC61850
 			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
 			private static extern int ControlObjectClient_getCtlValType(IntPtr self);
 
-			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
+            [DllImport ("iec61850", CallingConvention = CallingConvention.Cdecl)]
+            private static extern int ControlObjectClient_getLastError (IntPtr self);
+
+            [DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
             [return: MarshalAs(UnmanagedType.I1)]
 			private static extern bool ControlObjectClient_operate(IntPtr self, IntPtr ctlVal, UInt64 operTime);
 
@@ -190,7 +190,7 @@ namespace IEC61850
 			public delegate void CommandTerminationHandler (Object parameter, ControlObject controlObject);
 
             private IedConnection iedConnection;
-			private IntPtr controlObject;
+			private IntPtr self;
 
 			private CommandTerminationHandler commandTerminationHandler = null;
 			private Object commandTerminationHandlerParameter = null;
@@ -207,14 +207,14 @@ namespace IEC61850
 			{
                 this.iedConnection = iedConnection;
 
-				this.controlObject = ControlObjectClient_create(objectReference, connection);
+				this.self = ControlObjectClient_create(objectReference, connection);
 
-				if (this.controlObject == System.IntPtr.Zero)
+				if (this.self == System.IntPtr.Zero)
 					throw new IedConnectionException("Control object not found", 0);
 
 				intCommandTerminationHandler = new InternalCommandTerminationHandler (MyCommandTerminationHandler);
 
-				ControlObjectClient_setCommandTerminationHandler(controlObject, intCommandTerminationHandler, controlObject);
+				ControlObjectClient_setCommandTerminationHandler(self, intCommandTerminationHandler, self);
 			}
 
             /// <summary>
@@ -225,7 +225,7 @@ namespace IEC61850
             /// </returns>
 			public ControlModel GetControlModel ()
 			{
-				ControlModel controlModel = (ControlModel) ControlObjectClient_getControlModel(controlObject);
+				ControlModel controlModel = (ControlModel) ControlObjectClient_getControlModel(self);
 
 				return controlModel;
 			}
@@ -236,7 +236,7 @@ namespace IEC61850
 			/// <returns>MmsType required for the ctlVal value.</returns>
 			public MmsType GetCtlValType ()
 			{
-				MmsType ctlValType = (MmsType) ControlObjectClient_getCtlValType (controlObject);
+				MmsType ctlValType = (MmsType) ControlObjectClient_getCtlValType (self);
 
 				return ctlValType;
 			}
@@ -252,7 +252,17 @@ namespace IEC61850
             /// </param>
             public void SetOrigin (string originator, OrCat originatorCategory)
             {
-                ControlObjectClient_setOrigin(controlObject, originator, (int) originatorCategory);
+                ControlObjectClient_setOrigin(self, originator, (int) originatorCategory);
+            }
+
+            /// <summary>
+            /// Gets the error code of the last synchronous control action (operate, select, select-with-value, cancel)
+            /// </summary>
+            /// <value>error code.</value>
+            public IedClientError LastError {
+                get {
+                    return (IedClientError)ControlObjectClient_getLastError (self);
+                }
             }
 
             /// <summary>
@@ -342,7 +352,7 @@ namespace IEC61850
             /// <returns>true when the operation has been successful, false otherwise</returns>
 			public bool Operate (MmsValue ctlVal, UInt64 operTime)
 			{
-				return ControlObjectClient_operate(controlObject, ctlVal.valueReference, operTime);
+				return ControlObjectClient_operate(self, ctlVal.valueReference, operTime);
 			}
 
             private void nativeOperateHandler (UInt32 invokeId, IntPtr parameter, int err, int type, bool success)
@@ -477,7 +487,7 @@ namespace IEC61850
 
                 GCHandle handle = GCHandle.Alloc(callbackInfo);
 
-                UInt32 invokeId = ControlObjectClient_operateAsync(controlObject, out error, ctlVal.valueReference, operTime, nativeOperateHandler, GCHandle.ToIntPtr(handle));
+                UInt32 invokeId = ControlObjectClient_operateAsync(self, out error, ctlVal.valueReference, operTime, nativeOperateHandler, GCHandle.ToIntPtr(handle));
 
                 if (error != 0)
                 {
@@ -494,7 +504,7 @@ namespace IEC61850
             /// <returns>true when the selection has been successful, false otherwise</returns>
             public bool Select ()
             {
-                return ControlObjectClient_select(controlObject);
+                return ControlObjectClient_select(self);
             }
 
             /// <summary>
@@ -512,7 +522,7 @@ namespace IEC61850
 
                 GCHandle handle = GCHandle.Alloc(callbackInfo);
 
-                UInt32 invokeId = ControlObjectClient_selectAsync(controlObject, out error, nativeOperateHandler, GCHandle.ToIntPtr(handle));
+                UInt32 invokeId = ControlObjectClient_selectAsync(self, out error, nativeOperateHandler, GCHandle.ToIntPtr(handle));
 
                 if (error != 0)
                 {
@@ -530,7 +540,7 @@ namespace IEC61850
             /// <returns>true when the selection has been successful, false otherwise</returns>
             public bool SelectWithValue (MmsValue ctlVal)
             {
-                return ControlObjectClient_selectWithValue(controlObject, ctlVal.valueReference);
+                return ControlObjectClient_selectWithValue(self, ctlVal.valueReference);
             }
 
             /// <summary>
@@ -624,7 +634,7 @@ namespace IEC61850
 
                 GCHandle handle = GCHandle.Alloc(callbackInfo);
 
-                UInt32 invokeId = ControlObjectClient_selectWithValueAsync(controlObject, out error, ctlVal.valueReference, nativeOperateHandler, GCHandle.ToIntPtr(handle));
+                UInt32 invokeId = ControlObjectClient_selectWithValueAsync(self, out error, ctlVal.valueReference, nativeOperateHandler, GCHandle.ToIntPtr(handle));
 
                 if (error != 0)
                 {
@@ -645,7 +655,7 @@ namespace IEC61850
             /// <exception cref="IedConnectionException">This exception is thrown if there is a connection or service error</exception>
             public bool Cancel () 
             {
-                return ControlObjectClient_cancel(controlObject);
+                return ControlObjectClient_cancel(self);
             }
 
             /// <summary>
@@ -659,7 +669,7 @@ namespace IEC61850
 
                 GCHandle handle = GCHandle.Alloc(callbackInfo);
 
-                UInt32 invokeId = ControlObjectClient_cancelAsync(controlObject, out error, nativeOperateHandler, GCHandle.ToIntPtr(handle));
+                UInt32 invokeId = ControlObjectClient_cancelAsync(self, out error, nativeOperateHandler, GCHandle.ToIntPtr(handle));
 
                 if (error != 0)
                 {
@@ -676,7 +686,7 @@ namespace IEC61850
 			[Obsolete("use SetSynchroCheck instead")]
             public void EnableSynchroCheck ()
             {
-				ControlObjectClient_setSynchroCheck (controlObject, true);
+				ControlObjectClient_setSynchroCheck (self, true);
             }
 
             /// <summary>
@@ -685,7 +695,7 @@ namespace IEC61850
 			[Obsolete("use SetInterlockCheck instead")]
 			public void EnableInterlockCheck ()
             {
-				ControlObjectClient_setInterlockCheck (controlObject, true);
+				ControlObjectClient_setInterlockCheck (self, true);
             }
 
 			/// <summary>
@@ -693,7 +703,7 @@ namespace IEC61850
 			/// </summary>
 			public void SetInterlockCheck (bool value)
 			{
-				ControlObjectClient_setInterlockCheck (controlObject, value);
+				ControlObjectClient_setInterlockCheck (self, value);
 			}
 
 			/// <summary>
@@ -701,7 +711,7 @@ namespace IEC61850
 			/// </summary>
 			public void SetSynchroCheck (bool value)
 			{
-				ControlObjectClient_setSynchroCheck (controlObject, value);
+				ControlObjectClient_setSynchroCheck (self, value);
 			}
 
 			/// <summary>
@@ -709,7 +719,7 @@ namespace IEC61850
 			/// </summary>
 			public void SetTestMode (bool value)
 			{
-				ControlObjectClient_setTestMode (controlObject, value);
+				ControlObjectClient_setTestMode (self, value);
 			}
 
 			/// <summary>
@@ -720,7 +730,7 @@ namespace IEC61850
 			/// </returns>
 			public LastApplError GetLastApplError ()
 			{
-				LastApplErrorInternal lastApplError = ControlObjectClient_getLastApplError(controlObject);
+				LastApplErrorInternal lastApplError = ControlObjectClient_getLastApplError(self);
 
 				return new LastApplError(lastApplError);
 			}
@@ -741,9 +751,9 @@ namespace IEC61850
 			}
 
 			protected virtual void Dispose(bool disposing) {
-				if (this.controlObject != System.IntPtr.Zero) {
-					ControlObjectClient_destroy (controlObject);
-					this.controlObject = System.IntPtr.Zero;
+				if (this.self != System.IntPtr.Zero) {
+					ControlObjectClient_destroy (self);
+					this.self = System.IntPtr.Zero;
 				}
 			}
 
diff --git a/dotnet/IEC61850forCSharp/IEC61850ClientAPI.cs b/dotnet/IEC61850forCSharp/IEC61850ClientAPI.cs
index 4f613bb9..6a0f8ae9 100644
--- a/dotnet/IEC61850forCSharp/IEC61850ClientAPI.cs
+++ b/dotnet/IEC61850forCSharp/IEC61850ClientAPI.cs
@@ -1,7 +1,7 @@
 /*
  *  IEC61850ClientAPI.cs
  *
- *  Copyright 2014-2016 Michael Zillgith
+ *  Copyright 2014-2019 Michael Zillgith
  *
  *  This file is part of libIEC61850.
  *
@@ -29,14 +29,10 @@ using System.Collections;
 using IEC61850.Common;
 using IEC61850.TLS;
 
-/// <summary>
-/// IEC 61850 API for the libiec61850 .NET wrapper library
-/// </summary>
+// IEC 61850 API for the libiec61850 .NET wrapper library
 namespace IEC61850
 {
-    /// <summary>
-    /// IEC 61850 client API.
-    /// </summary>
+    // IEC 61850 client API.
     namespace Client
     {
 
@@ -201,7 +197,9 @@ namespace IEC61850
             }
         }
 
-
+        /// <summary>
+        /// Represents a variable in a log entry
+        /// </summary>
         public class MmsJournalVariable
         {
             [DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
@@ -265,6 +263,10 @@ namespace IEC61850
                 this.self = self;
             }
 
+            /// <summary>
+            /// Gets the journal variables.
+            /// </summary>
+            /// <returns>The journal variables.</returns>
             public List<MmsJournalVariable> GetJournalVariables()
             {
                 if (variables == null)
@@ -289,7 +291,10 @@ namespace IEC61850
                 return variables;
             }
 
-
+            /// <summary>
+            /// Gets the entry identifier of the log entry
+            /// </summary>
+            /// <returns>The entry identifier.</returns>
             public byte[] GetEntryID()
             {
                 IntPtr mmsValuePtr = MmsJournalEntry_getEntryID(self);
@@ -301,6 +306,10 @@ namespace IEC61850
                 return octetString;
             }
 
+            /// <summary>
+            /// Gets the occurence time of the log entry
+            /// </summary>
+            /// <returns>The occurence time.</returns>
             public ulong GetOccurenceTime()
             {
                 IntPtr mmsValuePtr = MmsJournalEntry_getOccurenceTime(self);
@@ -310,6 +319,9 @@ namespace IEC61850
                 return mmsValue.GetBinaryTimeAsUtcMs();
             }
 
+            /// <summary>
+            /// Releases all resource used by the <see cref="T:IEC61850.Client.MmsJournalEntry"/> object.
+            /// </summary>
             public void Dispose()
             {
                 if (self != IntPtr.Zero)
diff --git a/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs b/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs
index efff22ef..683d646b 100644
--- a/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs
+++ b/dotnet/IEC61850forCSharp/IEC61850ServerAPI.cs
@@ -21,26 +21,21 @@
  *  See COPYING file for the complete license text.
  */
 using System;
-using System.Text;
-using System.Runtime.InteropServices;
 using System.Collections.Generic;
-using System.Collections;
-
+using System.Runtime.InteropServices;
 using IEC61850.Common;
 using IEC61850.TLS;
 
-/// <summary>
-/// IEC 61850 API for the libiec61850 .NET wrapper library
-/// </summary>
+// IEC 61850 API for the libiec61850 .NET wrapper library
 namespace IEC61850
 {
-	/// <summary>
-	/// IEC 61850 server API.
-	/// </summary>
-	namespace Server
-	{
-		
-		public class ConfigFileParser
+    // IEC 61850 server API.
+    namespace Server
+    {
+        /// <summary>
+        /// Config file parser.
+        /// </summary>
+        public class ConfigFileParser
 		{
 
 			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
@@ -69,6 +64,9 @@ namespace IEC61850
 			}
 		}
 
+        /// <summary>
+        /// Representation of the IED server data model
+        /// </summary>
 		public class IedModel
 		{
 			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
@@ -93,6 +91,10 @@ namespace IEC61850
 				this.self = self;
 			}
 
+            /// <summary>
+            /// Initializes a new instance of the <see cref="T:IEC61850.Server.IedModel"/> class.
+            /// </summary>
+            /// <param name="name">IED name</param>
 			public IedModel(string name)
 			{
 				self = IedModel_create(name);
@@ -159,8 +161,6 @@ namespace IEC61850
 
 				return getModelNodeFromNodeRef (nodeRef);
 			}
-
-
 		}
 
 		public class LogicalDevice : ModelNode
@@ -483,8 +483,6 @@ namespace IEC61850
 
 		public class ClientConnection 
 		{
-			
-
 			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
 			static extern IntPtr ClientConnection_getPeerAddress(IntPtr self);
 
@@ -505,6 +503,99 @@ namespace IEC61850
 			}
 		}
 
+        /// <summary>
+        /// Represents additional context information of the control action that caused the callback invokation
+        /// </summary>
+        public class ControlAction
+        {
+            [DllImport ("iec61850", CallingConvention = CallingConvention.Cdecl)]
+            static extern void ControlAction_setAddCause (IntPtr self, int addCause);
+
+            [DllImport ("iec61850", CallingConvention = CallingConvention.Cdecl)]
+            static extern int ControlAction_getOrCat (IntPtr self);
+
+            [DllImport ("iec61850", CallingConvention = CallingConvention.Cdecl)]
+            static extern IntPtr ControlAction_getOrIdent (IntPtr self, ref int size);
+
+            [DllImport ("iec61850", CallingConvention = CallingConvention.Cdecl)]
+            static extern IntPtr ControlAction_getClientConnection (IntPtr self);
+
+            private IntPtr self;
+            private IedServer.ControlHandlerInfo info;
+            private IedServer iedServer;
+
+            internal ControlAction (IntPtr self, IedServer.ControlHandlerInfo info, IedServer iedServer)
+            {
+                this.self = self;
+                this.info = info;
+                this.iedServer = iedServer;
+            }
+
+            /// <summary>
+            /// Sets the add cause for the next command termination or application error message
+            /// </summary>
+            /// <param name="addCause">the additional cause code</param>
+            public void SetAddCause (ControlAddCause addCause)
+            {
+                ControlAction_setAddCause (self, (int)addCause);
+            }
+
+            /// <summary>
+            /// Gets the originator category provided by the client
+            /// </summary>
+            /// <returns>The or cat.</returns>
+            public OrCat GetOrCat ()
+            {
+                return (OrCat)ControlAction_getOrCat (self);
+            }
+
+            /// <summary>
+            ///  Get the originator identifier provided by the client
+            /// </summary>
+            /// <returns>The or ident.</returns>
+            public byte [] GetOrIdent ()
+            {
+                int size = 0;
+
+                IntPtr orIdentPtr = ControlAction_getOrIdent (self, ref size);
+
+                if (orIdentPtr == IntPtr.Zero)
+                    return null;
+
+                byte [] orIdent = new byte [size];
+
+                Marshal.Copy (orIdentPtr, orIdent, 0, size);
+
+                return orIdent;
+            }
+
+            /// <summary>
+            /// Gets the control object that is subject to this action
+            /// </summary>
+            /// <returns>the controllable data object instance</returns>
+            public DataObject GetControlObject ()
+            {
+                return info.controlObject;
+            }
+
+            /// <summary>
+            /// Gets the client object associated with the client that caused the control action
+            /// </summary>
+            /// <returns>The client connection.</returns>
+            public ClientConnection GetClientConnection ()
+            {
+                ClientConnection con = null;
+
+                IntPtr conPtr = ControlAction_getClientConnection (self);
+
+                if (conPtr != IntPtr.Zero) {
+                    iedServer.clientConnections.TryGetValue (conPtr, out con);
+                }
+
+                return con;
+            }
+        }
+
 		public delegate MmsDataAccessError WriteAccessHandler (DataAttribute dataAttr, MmsValue value, 
 			ClientConnection connection, object parameter);
 
@@ -523,9 +614,9 @@ namespace IEC61850
 			WAITING = 2
 		}
 
-		public delegate ControlHandlerResult ControlWaitForExecutionHandler (DataObject controlObject, object parameter, MmsValue ctlVal, bool test, bool synchroCheck);
+		public delegate ControlHandlerResult ControlWaitForExecutionHandler (ControlAction action, object parameter, MmsValue ctlVal, bool test, bool synchroCheck);
 
-		public delegate ControlHandlerResult ControlHandler (DataObject controlObject, object parameter, MmsValue ctlVal, bool test);
+		public delegate ControlHandlerResult ControlHandler (ControlAction action, object parameter, MmsValue ctlVal, bool test);
 
 		public enum CheckHandlerResult {
 			/// <summary>
@@ -550,8 +641,7 @@ namespace IEC61850
 			OBJECT_UNDEFINED = 4
 		}
 
-		public delegate CheckHandlerResult CheckHandler (DataObject controlObject, object parameter, MmsValue ctlVal, bool test, bool interlockCheck, 
-			ClientConnection connection);
+		public delegate CheckHandlerResult CheckHandler (ControlAction action, object parameter, MmsValue ctlVal, bool test, bool interlockCheck);
 
 		/// <summary>
 		/// This class acts as the entry point for the IEC 61850 client API. It represents a single
@@ -615,13 +705,13 @@ namespace IEC61850
 			static extern IntPtr IedServer_getAttributeValue(IntPtr self, IntPtr dataAttribute);
 
 			[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-			private delegate int InternalControlPerformCheckHandler (IntPtr parameter, IntPtr ctlVal, [MarshalAs(UnmanagedType.I1)] bool test, [MarshalAs(UnmanagedType.I1)] bool interlockCheck, IntPtr connection);
+			private delegate int InternalControlPerformCheckHandler (IntPtr action, IntPtr parameter, IntPtr ctlVal, [MarshalAs(UnmanagedType.I1)] bool test, [MarshalAs(UnmanagedType.I1)] bool interlockCheck);
 
 			[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-			private delegate int InternalControlWaitForExecutionHandler (IntPtr parameter, IntPtr ctlVal, [MarshalAs(UnmanagedType.I1)] bool test, [MarshalAs(UnmanagedType.I1)] bool synchoCheck);
+			private delegate int InternalControlWaitForExecutionHandler (IntPtr action, IntPtr parameter, IntPtr ctlVal, [MarshalAs(UnmanagedType.I1)] bool test, [MarshalAs(UnmanagedType.I1)] bool synchoCheck);
 
 			[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
-			private delegate int InternalControlHandler (IntPtr parameter, IntPtr ctlVal, [MarshalAs(UnmanagedType.I1)] bool test);
+			private delegate int InternalControlHandler (IntPtr action, IntPtr parameter, IntPtr ctlVal, [MarshalAs(UnmanagedType.I1)] bool test);
 
 			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
 			static extern void IedServer_setWaitForExecutionHandler(IntPtr self, IntPtr node, InternalControlWaitForExecutionHandler handler, IntPtr parameter);
@@ -665,7 +755,7 @@ namespace IEC61850
 			private InternalControlPerformCheckHandler internalControlPerformCheckHandlerRef = null;
 			private InternalControlWaitForExecutionHandler internalControlWaitForExecutionHandlerRef = null;
 
-			private class ControlHandlerInfo {
+			internal class ControlHandlerInfo {
 				public DataObject controlObject = null;
 				public GCHandle handle;
 
@@ -691,42 +781,46 @@ namespace IEC61850
 
 			private Dictionary<DataObject, ControlHandlerInfo> controlHandlers = new Dictionary<DataObject, ControlHandlerInfo> ();
 
-			int internalControlHandler (IntPtr parameter, IntPtr ctlVal, bool test)
+			int InternalControlHandlerImpl (IntPtr action, IntPtr parameter, IntPtr ctlVal, bool test)
 			{
 				GCHandle handle = GCHandle.FromIntPtr (parameter);
 
 				ControlHandlerInfo info = (ControlHandlerInfo)handle.Target;
 
+                ControlAction controlAction = new ControlAction (action, info, this);
+
 				if (info != null & info.controlHandler != null)
-					return (int)info.controlHandler (info.controlObject, info.controlHandlerParameter, new MmsValue (ctlVal), test);
+					return (int)info.controlHandler (controlAction, info.controlHandlerParameter, new MmsValue (ctlVal), test);
 				else
 					return (int)ControlHandlerResult.FAILED;
 			}
 
-			int internalCheckHandler(IntPtr parameter, IntPtr ctlVal, bool test, bool interlockCheck, IntPtr connection)
+			int InternalCheckHandlerImpl(IntPtr action, IntPtr parameter, IntPtr ctlVal, bool test, bool interlockCheck)
 			{
 				GCHandle handle = GCHandle.FromIntPtr (parameter);
 
 				ControlHandlerInfo info = (ControlHandlerInfo)handle.Target;
 
 				if (info != null & info.checkHandler != null) {
-					ClientConnection con = null;
 
-					clientConnections.TryGetValue (connection, out con);
+                    ControlAction controlAction = new ControlAction (action, info, this);
 
-					return (int)info.checkHandler (info.controlObject, info.checkHandlerParameter, new MmsValue (ctlVal), test, interlockCheck, con); 
+					return (int)info.checkHandler (controlAction, info.checkHandlerParameter, new MmsValue (ctlVal), test, interlockCheck); 
 				} else
 					return (int)CheckHandlerResult.OBJECT_UNDEFINED;
 			}
 
-			int internalControlWaitForExecutionHandler (IntPtr parameter, IntPtr ctlVal, bool test, bool synchoCheck)
+			int InternalControlWaitForExecutionHandlerImpl (IntPtr action, IntPtr parameter, IntPtr ctlVal, bool test, bool synchoCheck)
 			{
 				GCHandle handle = GCHandle.FromIntPtr (parameter);
 
 				ControlHandlerInfo info = (ControlHandlerInfo)handle.Target;
 
 				if (info != null & info.waitForExecHandler != null) {
-					return (int)info.waitForExecHandler (info.controlObject, info.waitForExecHandlerParameter, new MmsValue (ctlVal), test, synchoCheck);
+
+                    ControlAction controlAction = new ControlAction (action, info, this);
+
+                    return (int)info.waitForExecHandler (controlAction, info.waitForExecHandlerParameter, new MmsValue (ctlVal), test, synchoCheck);
 				} 
 				else
 					return (int)ControlHandlerResult.FAILED;
@@ -745,7 +839,7 @@ namespace IEC61850
 				}
 			}
 
-			int writeAccessHandler (IntPtr dataAttribute, IntPtr value, IntPtr connection, IntPtr parameter)
+			int WriteAccessHandlerImpl (IntPtr dataAttribute, IntPtr value, IntPtr connection, IntPtr parameter)
 			{
 				//object info = writeAccessHandlers.Item [dataAttribute];
 				WriteAccessHandlerInfo info;
@@ -761,7 +855,7 @@ namespace IEC61850
 
 			private Dictionary<IntPtr, WriteAccessHandlerInfo> writeAccessHandlers = new Dictionary<IntPtr, WriteAccessHandlerInfo> ();
 
-			private void connectionIndicationHandler (IntPtr iedServer, IntPtr clientConnection, bool connected, IntPtr parameter)
+			private void ConnectionIndicationHandlerImpl (IntPtr iedServer, IntPtr clientConnection, bool connected, IntPtr parameter)
 			{
 				if (connected == false) {
 					ClientConnection con = null;
@@ -785,9 +879,7 @@ namespace IEC61850
 				}
 			}
 
-			private Dictionary<IntPtr, ClientConnection> clientConnections = new Dictionary<IntPtr, ClientConnection> ();
-
-
+			internal Dictionary<IntPtr, ClientConnection> clientConnections = new Dictionary<IntPtr, ClientConnection> ();
 
 			public IedServer(IedModel iedModel, IedServerConfig config = null)
 			{
@@ -849,7 +941,7 @@ namespace IEC61850
 			public void Start(int tcpPort)
 			{
 				if (internalConnectionHandler == null)
-					internalConnectionHandler = new InternalConnectionHandler (connectionIndicationHandler);					
+					internalConnectionHandler = new InternalConnectionHandler (ConnectionIndicationHandlerImpl);					
 
 				IedServer_setConnectionIndicationHandler (self, internalConnectionHandler, IntPtr.Zero);
 
@@ -910,7 +1002,7 @@ namespace IEC61850
 				info.controlHandlerParameter = parameter;
 
 				if (internalControlHandlerRef == null)
-					internalControlHandlerRef = new InternalControlHandler (internalControlHandler);
+					internalControlHandlerRef = new InternalControlHandler (InternalControlHandlerImpl);
 
 				IedServer_setControlHandler(self, controlObject.self, internalControlHandlerRef, GCHandle.ToIntPtr(info.handle));
 			}
@@ -923,7 +1015,7 @@ namespace IEC61850
 				info.checkHandlerParameter = parameter;
 
 				if (internalControlPerformCheckHandlerRef == null)
-					internalControlPerformCheckHandlerRef = new InternalControlPerformCheckHandler (internalCheckHandler);
+					internalControlPerformCheckHandlerRef = new InternalControlPerformCheckHandler (InternalCheckHandlerImpl);
 
 				IedServer_setPerformCheckHandler(self, controlObject.self, internalControlPerformCheckHandlerRef, GCHandle.ToIntPtr(info.handle));
 			}
@@ -936,7 +1028,7 @@ namespace IEC61850
 				info.waitForExecHandlerParameter = parameter;
 
 				if (internalControlWaitForExecutionHandlerRef == null)
-					internalControlWaitForExecutionHandlerRef = new InternalControlWaitForExecutionHandler (internalControlWaitForExecutionHandler);
+					internalControlWaitForExecutionHandlerRef = new InternalControlWaitForExecutionHandler (InternalControlWaitForExecutionHandlerImpl);
 
 				IedServer_setWaitForExecutionHandler(self, controlObject.self, internalControlWaitForExecutionHandlerRef, GCHandle.ToIntPtr(info.handle));
 			}
@@ -946,7 +1038,7 @@ namespace IEC61850
 				writeAccessHandlers.Add (dataAttr.self, new WriteAccessHandlerInfo(handler, parameter, dataAttr));
 				//writeAccessHandlers.Item [dataAttr.self] = handler;
 
-				IedServer_handleWriteAccess (self, dataAttr.self, writeAccessHandler, IntPtr.Zero);
+				IedServer_handleWriteAccess (self, dataAttr.self, WriteAccessHandlerImpl, IntPtr.Zero);
 			}
 
 			public void SetWriteAccessPolicy(FunctionalConstraint fc, AccessPolicy policy)
diff --git a/dotnet/IEC61850forCSharp/MmsValue.cs b/dotnet/IEC61850forCSharp/MmsValue.cs
index 79f570a0..12b6f091 100644
--- a/dotnet/IEC61850forCSharp/MmsValue.cs
+++ b/dotnet/IEC61850forCSharp/MmsValue.cs
@@ -521,9 +521,12 @@ namespace IEC61850
 				if ((elementType == MmsType.MMS_ARRAY) || (elementType == MmsType.MMS_STRUCTURE)) {
 				
 					if ((index >= 0) && (index < Size ())) {
-						MmsValue_setElement (valueReference, index, elementValue.valueReference);
-					
-					} else
+                        if (elementValue != null)
+						    MmsValue_setElement (valueReference, index, elementValue.valueReference);
+                        else
+                            MmsValue_setElement (valueReference, index, IntPtr.Zero);
+
+                    } else
 						throw new MmsValueException ("Index out of bounds");
 				
 				} else
diff --git a/dotnet/server1/Program.cs b/dotnet/server1/Program.cs
index 62c7c5e3..a5910937 100644
--- a/dotnet/server1/Program.cs
+++ b/dotnet/server1/Program.cs
@@ -31,7 +31,7 @@ namespace server1
 
 			IedServer iedServer = new IedServer (iedModel, config);
 
-			iedServer.SetControlHandler (spcso1, delegate(DataObject controlObject, object parameter, MmsValue ctlVal, bool test) {
+			iedServer.SetControlHandler (spcso1, delegate(ControlAction action, object parameter, MmsValue ctlVal, bool test) {
                 bool val = ctlVal.GetBoolean();
 
                 if (val)
diff --git a/dotnet/tests/Test.cs b/dotnet/tests/Test.cs
index d1c38871..934bfe71 100644
--- a/dotnet/tests/Test.cs
+++ b/dotnet/tests/Test.cs
@@ -126,7 +126,11 @@ namespace tests
 
 			Assert.AreEqual (elem2.GetType (), MmsType.MMS_INTEGER);
 			Assert.AreEqual (elem2.ToInt32 (), 3);
-		}
+
+            val.SetElement (0, null);
+            val.SetElement (1, null);
+            val.SetElement (2, null);
+        }
 
 		[Test()]
 		public void MmsValueStructure()
@@ -147,6 +151,9 @@ namespace tests
 			MmsValue elem1 = val.GetElement (1);
 
 			Assert.AreEqual (elem1.GetType (), MmsType.MMS_BIT_STRING);
+
+            val.SetElement (0, null);
+            val.SetElement (1, null);
 		}
 
 		[Test ()]
@@ -428,7 +435,17 @@ namespace tests
 
 			IedServer iedServer = new IedServer (iedModel);
 
-			iedServer.SetControlHandler (spcso1, delegate(DataObject controlObject, object parameter, MmsValue ctlVal, bool test) {
+			iedServer.SetControlHandler (spcso1, delegate(ControlAction action, object parameter, MmsValue ctlVal, bool test) {
+
+                byte [] orIdent = action.GetOrIdent ();
+
+                string orIdentStr = System.Text.Encoding.UTF8.GetString (orIdent, 0, orIdent.Length);
+
+                Assert.AreEqual ("TEST1234", orIdentStr);
+                Assert.AreEqual (OrCat.MAINTENANCE, action.GetOrCat ());
+
+                Assert.AreSame (spcso1, action.GetControlObject ());
+
 				handlerCalled++;
 				return ControlHandlerResult.OK;
 			}, null);
@@ -440,6 +457,7 @@ namespace tests
 			connection.Connect ("localhost", 10002);
 
 			ControlObject controlClient = connection.CreateControlObject ("simpleIOGenericIO/GGIO1.SPCSO1");
+            controlClient.SetOrigin ("TEST1234", OrCat.MAINTENANCE);
 
 			Assert.IsNotNull (controlClient);
 
diff --git a/dotnet/tls_server_example/Program.cs b/dotnet/tls_server_example/Program.cs
index e7aa0cfc..115cc100 100644
--- a/dotnet/tls_server_example/Program.cs
+++ b/dotnet/tls_server_example/Program.cs
@@ -46,7 +46,7 @@ namespace tls_server_example
 
 			IedServer iedServer = new IedServer (iedModel, tlsConfig);
 
-			iedServer.SetControlHandler (spcso1, delegate(DataObject controlObject, object parameter, MmsValue ctlVal, bool test) {
+			iedServer.SetControlHandler (spcso1, delegate(ControlAction action, object parameter, MmsValue ctlVal, bool test) {
 				bool val = ctlVal.GetBoolean();
 
 				if (val)
diff --git a/src/iec61850/inc/iec61850_server.h b/src/iec61850/inc/iec61850_server.h
index cd4336fb..63c668f1 100644
--- a/src/iec61850/inc/iec61850_server.h
+++ b/src/iec61850/inc/iec61850_server.h
@@ -1086,7 +1086,7 @@ typedef enum {
 typedef void* ControlAction;
 
 /**
- * \brief Set the add cause for the next command termination or application error message
+ * \brief Sets the add cause for the next command termination or application error message
  *
  * \param self the control action instance
  * \param addCause the additional cause
@@ -1095,7 +1095,7 @@ LIB61850_API void
 ControlAction_setAddCause(ControlAction self, ControlAddCause addCause);
 
 /**
- * \brief Get the originator category provided by the client
+ * \brief Gets the originator category provided by the client
  *
  * \param self the control action instance
  *
@@ -1105,7 +1105,7 @@ LIB61850_API int
 ControlAction_getOrCat(ControlAction self);
 
 /**
- * \brief Get the originator identifier provided by the client
+ * \brief Gets the originator identifier provided by the client
  *
  * \param self the control action instance
  *
@@ -1115,7 +1115,7 @@ LIB61850_API uint8_t*
 ControlAction_getOrIdent(ControlAction self, int* orIdentSize);
 
 /**
- * \brief Get the client object associated with the client that caused the control action
+ * \brief Gets the client object associated with the client that caused the control action
  *
  * \param self the control action instance
  *
@@ -1125,7 +1125,7 @@ LIB61850_API ClientConnection
 ControlAction_getClientConnection(ControlAction self);
 
 /**
- * \brief Get the control object that is subject to this action
+ * \brief Gets the control object that is subject to this action
  *
  * \param self the control action instance
  *