Modified the implementation of side of pier support detection. Hopefully will now,

Added extra checking to ensure that a slew cannot be started whilst a slew is in progress.

Meade.net.Focuser.UnitTests/FocuserUnitTests.cs

@@ -42,8 +42,6 @@ namespace Meade.net.Focuser.UnitTests
 
             _sharedResourcesWrapperMock = new Mock<ISharedResourcesWrapper>();
 
-            _sharedResourcesWrapperMock.Setup(x => x.Lock(It.IsAny<Action>())).Callback<Action>(action => { action(); });
-
             _sharedResourcesWrapperMock.Setup(x => x.ReadProfile()).Returns(() => _profileProperties);
 
             _focuser = new ASCOM.Meade.net.Focuser(_utilMock.Object, _sharedResourcesWrapperMock.Object);
@@ -422,8 +420,6 @@ namespace Meade.net.Focuser.UnitTests
                 _sharedResourcesWrapperMock.Verify(x => x.SendBlind("F+", false), Times.Once);
             }
 
-            _sharedResourcesWrapperMock.Verify(x => x.Lock(It.IsAny<Action>()), Times.Once);
-
             _utilMock.Verify(x => x.WaitForMilliseconds(Math.Abs(position)), Times.Once);
             _utilMock.Verify(x => x.WaitForMilliseconds(Math.Abs(_profileProperties.BacklashCompensation)), Times.Never);
             _utilMock.Verify(x => x.WaitForMilliseconds(100), Times.Once());
@@ -455,8 +451,6 @@ namespace Meade.net.Focuser.UnitTests
                 _utilMock.Verify(x => x.WaitForMilliseconds(_profileProperties.BacklashCompensation), Times.Once);
                 _utilMock.Verify(x => x.WaitForMilliseconds(100), Times.Exactly(2));
             }
-
-            _sharedResourcesWrapperMock.Verify(x => x.Lock(It.IsAny<Action>()), Times.Once);
         }
 
         [Test]

Meade.net.Telescope.UnitTests/TelescopeUnitTests.cs

@@ -95,9 +95,6 @@ namespace Meade.net.Telescope.UnitTests
             _sharedResourcesWrapperMock.Setup(x => x.SendString("GZ", false)).Returns("DDD*MM’SS");
 
             _sharedResourcesWrapperMock.Setup(x => x.ReadProfile()).Returns(() =>_profileProperties);
-            _sharedResourcesWrapperMock.Setup(x => x.Lock(It.IsAny<Action>())).Callback<Action>(action => { action(); });
-            _sharedResourcesWrapperMock.Setup(x => x.Lock(It.IsAny<Func<ASCOM.Meade.net.Telescope.TelescopeDateDetails>>())).Returns<Func<ASCOM.Meade.net.Telescope.TelescopeDateDetails>>( func => func());
-            _sharedResourcesWrapperMock.Setup(x => x.Lock(It.IsAny<Func<AltitudeData>>())).Returns<Func<AltitudeData>>(func => func());
 
             _connectionInfo = new ConnectionInfo
             {
@@ -1930,11 +1927,12 @@ namespace Meade.net.Telescope.UnitTests
             Assert.That(excpetion.Method, Is.EqualTo("SetPark"));
         }
 
-        [Test]
+        [TestCase(TelescopeList.LX200CLASSIC, null)]
-        public void SideOfPier_Get_WhenMeridianFlipNotSupported_ThenThrowsException()
+        [TestCase(TelescopeList.Autostar497, TelescopeList.Autostar497_31Ee)]
+        [TestCase(TelescopeList.LX200GPS, TelescopeList.LX200GPS_42F)]
+        public void SideOfPier_Get_WhenMeridianFlipNotSupported_ThenThrowsException(string model, string firmware)
         {
-            // LX200 classic is a fork mounted scope so it does not support meridian flips
+            ConnectTelescope(model, firmware);
-            _sharedResourcesWrapperMock.Setup(x => x.ProductName).Returns(TelescopeList.LX200CLASSIC);
 
             var excpetion = Assert.Throws<PropertyNotImplementedException>(() =>
             {
@@ -1946,6 +1944,41 @@ namespace Meade.net.Telescope.UnitTests
             Assert.That(excpetion.AccessorSet, Is.False);
         }
 
+        [TestCase(TelescopeList.Autostar497, TelescopeList.Autostar497_43Eg)]
+        [TestCase(TelescopeList.LX200GPS, TelescopeList.LX200GPS_42G)]
+        public void SideOfPier_Get_WhenMeridianFlipSupported_ThenReturnsResult(string model, string firmware)
+        {
+            ConnectTelescope(model, firmware);
+
+            Assert.DoesNotThrow(() => { var result = _telescope.SideOfPier; });
+        }
+
+        [TestCase(TelescopeList.Autostar497, TelescopeList.Autostar497_43Eg, AlignmentModes.algAltAz, 'A')]
+        [TestCase(TelescopeList.Autostar497, TelescopeList.Autostar497_43Eg, AlignmentModes.algPolar, 'P')]
+        public void SideOfPier_Get_WhenMeridianFlipNotSupportedByAlignementMode_ThenThrowsException(string model, string firmware, AlignmentModes alignmode, char alignmentStatus)
+        {            
+            ConnectTelescope(model, firmware);
+            _testProperties.AlignmentStatus = new[] { alignmentStatus, 'T', '1' };
+
+            var excpetion = Assert.Throws<PropertyNotImplementedException>(() =>
+            {
+                var result = _telescope.SideOfPier;
+                Assert.Fail($"{result} should not have returned");
+            });
+
+            Assert.That(excpetion.Property, Is.EqualTo("SideOfPier"));
+            Assert.That(excpetion.AccessorSet, Is.False);
+        }
+
+        [TestCase(TelescopeList.Autostar497, TelescopeList.Autostar497_43Eg, AlignmentModes.algGermanPolar, 'G')]
+        public void SideOfPier_Get_WhenMeridianFlipSupportedByAlignementMode_ThenDoesNotThrow(string model, string firmware, AlignmentModes alignmode, char alignmentStatus)
+        {
+            ConnectTelescope(model, firmware);
+            _testProperties.AlignmentStatus = new[] { alignmentStatus, 'T', '1' };
+
+            Assert.DoesNotThrow(() => { var result = _telescope.SideOfPier; });
+        }
+
         [Test]
         public void SideOfPier_Set_ThenThrowsException()
         {
@@ -2119,7 +2152,7 @@ namespace Meade.net.Telescope.UnitTests
 
             _sharedResourcesWrapperMock.Verify(x => x.SendString("Gg", false), Times.Exactly(3));
             _sharedResourcesWrapperMock.Verify(x => x.SendChar("MS", false), Times.Exactly(2));
-            _sharedResourcesWrapperMock.Verify(x => x.SendString("D", false), Times.Exactly(3));
+            _sharedResourcesWrapperMock.Verify(x => x.SendString("D", false), Times.AtLeast(3));
         }
 
         [Test]
@@ -3272,12 +3305,15 @@ namespace Meade.net.Telescope.UnitTests
         {
             _sharedResourcesWrapperMock.Setup(x => x.SendChar("MS", false)).Returns("0");
 
+            var preTestItterations = 1;
             var slewCounter = 0;
             var iterations = 10;
             _sharedResourcesWrapperMock.Setup(x => x.SendString("D", false)).Returns(() =>
             {
                 slewCounter++;
-                if (slewCounter <= iterations)
+                if (slewCounter <= preTestItterations)
+                    return "";
+                else if (slewCounter <= iterations)
                     return "|";
                 return "";
             });
@@ -3289,7 +3325,7 @@ namespace Meade.net.Telescope.UnitTests
 
             _telescope.SlewToTarget();
 
-            _utilMock.Verify(x => x.WaitForMilliseconds(It.IsAny<int>()), Times.Exactly(iterations));
+            _utilMock.Verify(x => x.WaitForMilliseconds(It.IsAny<int>()), Times.Exactly(iterations - preTestItterations));
         }
 
         [Test]
@@ -3366,12 +3402,15 @@ namespace Meade.net.Telescope.UnitTests
 
             _sharedResourcesWrapperMock.Setup(x => x.SendChar("MS", false)).Returns("0");
 
+            var preTestItterations = 1;
             var slewCounter = 0;
             var iterations = 10;
             _sharedResourcesWrapperMock.Setup(x => x.SendString("D", false)).Returns(() =>
             {
                 slewCounter++;
-                if (slewCounter <= iterations)
+                if (slewCounter <= preTestItterations)
+                    return "";
+                else if (slewCounter <= iterations)
                     return "|";
                 return "";
             });
@@ -3383,7 +3422,7 @@ namespace Meade.net.Telescope.UnitTests
             Assert.That(_telescope.TargetDeclination, Is.EqualTo(dmsResult));
             _sharedResourcesWrapperMock.Verify(x => x.SendChar("MS", false), Times.Once);
 
-            _utilMock.Verify(x => x.WaitForMilliseconds(It.IsAny<int>()), Times.Exactly(iterations));
+            _utilMock.Verify(x => x.WaitForMilliseconds(It.IsAny<int>()), Times.Exactly(iterations - preTestItterations));
         }
 
         [Test]
@@ -3486,12 +3525,15 @@ namespace Meade.net.Telescope.UnitTests
 
             _sharedResourcesWrapperMock.Setup(x => x.SendChar("MS", false)).Returns("0");
 
+            var preTestItterations = 1;
             var slewCounter = 0;
             var iterations = 10;
             _sharedResourcesWrapperMock.Setup(x => x.SendString("D", false)).Returns(() =>
             {
                 slewCounter++;
-                if (slewCounter <= iterations)
+                if (slewCounter <= preTestItterations)
+                    return "";
+                else if (slewCounter <= iterations)
                     return "|";
                 return "";
             });
@@ -3503,7 +3545,7 @@ namespace Meade.net.Telescope.UnitTests
             Assert.That(_telescope.TargetRightAscension, Is.EqualTo(_testProperties.rightAscension));
             Assert.That(_telescope.TargetDeclination, Is.EqualTo(_testProperties.declination));
             _sharedResourcesWrapperMock.Verify(x => x.SendChar("MS", false), Times.Once);
-            _utilMock.Verify(x => x.WaitForMilliseconds(It.IsAny<int>()), Times.Exactly(iterations));
+            _utilMock.Verify(x => x.WaitForMilliseconds(It.IsAny<int>()), Times.Exactly(iterations - preTestItterations));
         }
 
         [Test]

Meade.net.Telescope/Telescope.cs

@@ -649,7 +649,7 @@ namespace ASCOM.Meade.net
         // According to "A User's Guide to the Meade LXD55 and LXD75 Telescopes" Autostar supports meridian flip so
         // we assume that for any telescope that supports the GW command and is not in Alt-Az mode then
         // meridian flip on slew is supported
-        private bool IsMeridianFlipOnSlewSupported() => IsGwCommandSupported() && AlignmentMode != AlignmentModes.algAltAz;
+        private bool IsMeridianFlipOnSlewSupported() => IsGwCommandSupported() && AlignmentMode == AlignmentModes.algGermanPolar;
 
         private bool FirmwareIsGreaterThan(string minVersion)
         {
@@ -734,12 +734,10 @@ namespace ASCOM.Meade.net
             {
                 LogMessage("SetLongFormat", "Long coordinate format not supported for this mount");
 
-                SharedResourcesWrapper.Lock(() => SharedResourcesWrapper.IsLongFormat = false);
+                SharedResourcesWrapper.IsLongFormat = false;
                 return;
             }
 
-            SharedResourcesWrapper.Lock(() =>
-            {
             var result = SharedResourcesWrapper.SendString("GZ");
             LogMessage("SetLongFormat", $"Get - Azimuth {result}");
             //:GZ# Get telescope azimuth
@@ -766,7 +764,6 @@ namespace ASCOM.Meade.net
             {
                 LogMessage("SetLongFormat", $"Long coordinate format: {setLongFormat} ");
             }
-            });
 
             LogMessage("SetLongFormat", $"Long coordinate format: {setLongFormat} ");
         }
@@ -1135,13 +1132,13 @@ namespace ASCOM.Meade.net
 
         private HorizonCoordinates CalcAltAzFromTelescopeEqData()
         {
-            var altitudeData = SharedResourcesWrapper.Lock(() => new AltitudeData
+            var altitudeData = new AltitudeData
             {
                 UtcDateTime = UTCDate,
                 SiteLongitude = SiteLongitude,
                 SiteLatitude = SiteLatitude,
                 EquatorialCoordinates = GetTelescopeRaAndDec()
-            });
+            };
 
             double hourAngle = _astroMaths.RightAscensionToHourAngle(altitudeData.UtcDateTime,
                 altitudeData.SiteLongitude,
@@ -2181,29 +2178,24 @@ namespace ASCOM.Meade.net
             var latitude = SiteLatitude;
             var longitude = SiteLongitude;
 
-            SharedResourcesWrapper.Lock(() =>
-            {
             var raDec = _astroMaths.ConvertHozToEq(utcDateTime, latitude, longitude, altAz);
 
             TargetRightAscension = raDec.RightAscension;
             TargetDeclination = raDec.Declination;
 
             DoSlewAsync(true);
-
-                //TargetAltitude = altitude;
-                //TargetAzimuth = azimuth;
-
-                //DoSlewAsync(false);
-            });
         }
 
         private void DoSlewAsync(bool polar)
         {
             CheckConnected("DoSlewAsync");
             CheckParked();
-
+            if (Slewing)
-            SharedResourcesWrapper.Lock(() =>
             {
+                LogMessage("DoSlewAsync", "Cannot start a slew whilst slew is in progress.");
+                throw new ASCOM.InvalidOperationException("Cannot start a slew whilst slew is in progress.");
+            }
+
             switch (polar)
             {
                 case true:
@@ -2224,7 +2216,8 @@ namespace ASCOM.Meade.net
                             {
                                 // Update side of pier to destination side of pier
                                 // Assumption: Mount will do meridian flip if required
-                                    SharedResourcesWrapper.SideOfPier = DestinationSideOfPier(TargetRightAscension, TargetDeclination);
+                                SharedResourcesWrapper.SideOfPier =
+                                    DestinationSideOfPier(TargetRightAscension, TargetDeclination);
                             }
 
                             SetSlewingMinEndTime();
@@ -2263,10 +2256,10 @@ namespace ASCOM.Meade.net
                     {
                         throw new InvalidOperationException("fault");
                     }
+
                     SetSlewingMinEndTime();
                     break;
             }
-            });
         }
 
         public void SlewToCoordinates(double rightAscension, double declination)
@@ -2450,17 +2443,15 @@ namespace ASCOM.Meade.net
         public void SyncToCoordinates(double rightAscension, double declination)
         {
             LogMessage("SyncToCoordinates", $"RA={rightAscension} Dec={declination}");
-            LogMessage("SyncToCoordinates", $"RA={_utilitiesExtra.HoursToHMS(rightAscension)} Dec={_utilitiesExtra.HoursToHMS(declination)}");
+            LogMessage("SyncToCoordinates",
+                $"RA={_utilitiesExtra.HoursToHMS(rightAscension)} Dec={_utilitiesExtra.HoursToHMS(declination)}");
             CheckConnected("SyncToCoordinates");
             CheckParked();
 
-            SharedResourcesWrapper.Lock(() =>
-            {
             TargetRightAscension = rightAscension;
             TargetDeclination = declination;
 
             SyncToTarget();
-            });
         }
 
         public void SyncToTarget()
@@ -2612,13 +2603,15 @@ namespace ASCOM.Meade.net
             get
             {
                 LogMessage("Tracking", "Get");
+                bool isTracking = true;
                 if (IsGwCommandSupported())
                 {
                     var alignmentStatus = GetScopeAlignmentStatus();
-                    return alignmentStatus.Tracking;
+                    isTracking = alignmentStatus.Tracking;
                 }
 
-                return true;
+                LogMessage("Tracking", $"Get = {isTracking}");
+                return isTracking;
             }
             set
             {
@@ -2731,9 +2724,7 @@ namespace ASCOM.Meade.net
                 {
                     CheckParked();
 
-                    var telescopeDateDetails = SharedResourcesWrapper.Lock(() =>
+                    var telescopeDateDetails = new TelescopeDateDetails
-                    {
-                        var tdd = new TelescopeDateDetails
                     {
                         TelescopeDate = SharedResourcesWrapper.SendString("GC"),
                         //:GC# Get current date.
@@ -2746,9 +2737,6 @@ namespace ASCOM.Meade.net
                         UtcCorrection = GetUtcCorrection()
                     };
 
-                        return tdd;
-                    });
-
                     int month = telescopeDateDetails.TelescopeDate.Substring(0, 2).ToInteger();
                     int day = telescopeDateDetails.TelescopeDate.Substring(3, 2).ToInteger();
                     int year = telescopeDateDetails.TelescopeDate.Substring(6, 2).ToInteger();
@@ -2783,8 +2771,6 @@ namespace ASCOM.Meade.net
 
                 CheckConnected("UTCDate Set");
 
-                SharedResourcesWrapper.Lock(() =>
-                {
                 var utcCorrection = GetUtcCorrection();
                 var localDateTime = value - utcCorrection;
 
@@ -2816,7 +2802,6 @@ namespace ASCOM.Meade.net
                 //throwing away these two strings which represent
                 SharedResourcesWrapper.ReadTerminated(); //Updating Planetary Data#
                 SharedResourcesWrapper.ReadTerminated(); //                       #
-                });
             }
         }
 

Meade.net.focuser/Focuser.cs

@@ -298,8 +298,6 @@ namespace ASCOM.Meade.net
             if (ReverseFocusDirection)
                 direction = !direction;
             
-            SharedResourcesWrapper.Lock(() =>
-            {
             //backlash compensation.
             var backlashCompensationSteps = direction ? Math.Abs(BacklashCompensation) : 0;
 
@@ -320,7 +318,6 @@ namespace ASCOM.Meade.net
             DynamicBreaking(direction);
             //todo implement dynamic braking
             //dynamic breaking is sending the command to move in the opposite direction immediatly followed by the command to stop.
-            });
         }
 
         private void DynamicBreaking(bool directionOut)

Meade.net/TelescopeList.cs

@@ -23,6 +23,7 @@
         // ReSharper disable once InconsistentNaming
         public const string LX200GPS = "LX2001";
 
+        public const string LX200GPS_42F = "4.2F";
         // ReSharper disable once InconsistentNaming
         public const string LX200GPS_42G = "4.2G";
         #endregion

Meade.net/Wrapper/SharedResourcesWrapper.cs

@@ -13,9 +13,6 @@ namespace ASCOM.Meade.net.Wrapper
 
         string FirmwareVersion { get; }
         
-        void Lock(Action action);
-        T Lock<T>(Func<T> func);
-
         string SendString(string message, bool raw = false);
         void SendBlind(string message, bool raw = false);
         bool SendBool(string command, bool raw = false);
@@ -69,16 +66,6 @@ namespace ASCOM.Meade.net.Wrapper
 
         public string FirmwareVersion => SharedResources.FirmwareVersion;
 
-        public void Lock(Action action)
-        {
-            SharedResources.Lock(action);
-        }
-
-        public T Lock<T>(Func<T> func)
-        {
-            return SharedResources.Lock(func);
-        }
-
         public string SendString(string message, bool raw = false)
         {
             return SharedResources.SendString(message, raw);