Implemented AbortSlew and did some code tidy up.

MeadeAutostar497/Controller/ISerialProcessor.cs

@@ -0,0 +1,26 @@
+using System.IO.Ports;
+using System.Runtime.InteropServices;
+
+namespace ASCOM.MeadeAutostar497.Controller
+{
+    [ComVisible(false)]
+    public interface ISerialProcessor
+    {
+        bool IsOpen { get; }
+        bool DtrEnable { get; set; }
+        bool RtsEnable { get; set; }
+        int BaudRate { get; set; }
+        int DataBits { get; set; }
+        StopBits StopBits { get; set; }
+        Parity Parity { get; set; }
+        string PortName { get; set; }
+        string[]  GetPortNames();
+        void Open();
+        void Close();
+
+        string CommandTerminated(string command, string terminator);
+        char CommandChar(string command);
+        string ReadTerminated(string terminator);
+        void Command(string command);
+    }
+}

MeadeAutostar497/Controller/ITelescopeController.cs

@@ -1,15 +1,14 @@
 using System;
-using System.IO.Ports;
 
 namespace ASCOM.MeadeAutostar497.Controller
 {
     public interface ITelescopeController
     {
-        ISerialProcessor SerialPort { get; set; }
         string Port { get; set; }
         bool Connected { get; set; }
 
         bool Slewing { get; }
         DateTime utcDate { get; set; }
+        void AbortSlew();
     }
 }

MeadeAutostar497/Controller/SerialProcessor.cs

@@ -1,31 +1,10 @@
 using System;
 using System.IO.Ports;
 using System.Runtime.InteropServices;
-using System.Text;
 using System.Threading;
 
 namespace ASCOM.MeadeAutostar497.Controller
 {
-    [ComVisible(false)]
-    public interface ISerialProcessor
-    {
-        bool IsOpen { get; }
-        bool DtrEnable { get; set; }
-        bool RtsEnable { get; set; }
-        int BaudRate { get; set; }
-        int DataBits { get; set; }
-        StopBits StopBits { get; set; }
-        Parity Parity { get; set; }
-        string PortName { get; set; }
-        string[]  GetPortNames();
-        void Open();
-        void Close();
-
-        string CommandTerminated(string command, string terminator);
-        char CommandChar(string command);
-        string ReadTerminated(string terminator);
-    }
-
     [ComVisible(false)]
     public class SerialProcessor : ISerialProcessor
     {
@@ -134,5 +113,18 @@ namespace ASCOM.MeadeAutostar497.Controller
                 serialMutex.ReleaseMutex();
             }
         }
+
+        public void Command(string command)
+        {
+            serialMutex.WaitOne();
+            try
+            {
+                _serialPort.Write(command);
+            }
+            finally
+            {
+                serialMutex.ReleaseMutex();
+            }
+        }
     }
 }

MeadeAutostar497/Controller/TelescopeController.cs

@@ -1,11 +1,6 @@
 using System;
-using System.Configuration;
-using System.Data;
 using System.IO.Ports;
 using System.Linq;
-using System.Threading;
-using ASCOM.Utilities;
-using ASCOM.Utilities.Interfaces;
 
 namespace ASCOM.MeadeAutostar497.Controller
 {
@@ -98,7 +93,7 @@ namespace ASCOM.MeadeAutostar497.Controller
 
         private void TestConnectionActive()
         {
-            var firmwareVersionNumber = SerialPort.CommandTerminated(":GVN#", "#");
+            var firmwareVersionNumber = SerialPort.CommandTerminated("#:GVN#", "#");
             if (string.IsNullOrEmpty(firmwareVersionNumber))
             {
                 throw new InvalidOperationException("Failed to communicate with telescope."); 
@@ -155,10 +150,16 @@ namespace ASCOM.MeadeAutostar497.Controller
                     throw new InvalidOperationException("Failed to set local time");
                 }
 
-                SerialPort.ReadTerminated("#");
-                SerialPort.ReadTerminated("#");
+                //throwing away these two strings which represent 
+                SerialPort.ReadTerminated("#");  //Updating Planetary Data#
+                SerialPort.ReadTerminated("#");  //                       #
             }
 
         }
+
+        public void AbortSlew()
+        {
+            SerialPort.Command("#:Q#");
+        }
     }
 }