diff --git a/DeviceAdapters/DemoCamera/DemoCamera.cpp b/DeviceAdapters/DemoCamera/DemoCamera.cpp
index 54175e2dd..07b3d0fab 100644
--- a/DeviceAdapters/DemoCamera/DemoCamera.cpp
+++ b/DeviceAdapters/DemoCamera/DemoCamera.cpp
@@ -236,6 +236,9 @@ CDemoCamera::CDemoCamera() :
 	fractionOfPixelsToDropOrSaturate_(0.002),
    shouldRotateImages_(false),
    shouldDisplayImageNumber_(false),
+   busy_(false),
+   imageCounter_(0),
+   stopOnOverFlow_(true),
    stripeWidth_(1.0),
    supportsMultiROI_(false),
    multiROIFillValue_(0),
@@ -3061,9 +3064,10 @@ int CDemoStateDevice::OnNumberOfStates(MM::PropertyBase* pProp, MM::ActionType e
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 CDemoLightPath::CDemoLightPath() : 
-numPos_(3), 
-busy_(false), 
-initialized_(false)
+   position_(0),
+   numPos_(3), 
+   busy_(false), 
+   initialized_(false)
 {
    InitializeDefaultErrorMessages();
    // parent ID display
@@ -3180,10 +3184,12 @@ int CDemoLightPath::OnState(MM::PropertyBase* pProp, MM::ActionType eAct)
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 CDemoObjectiveTurret::CDemoObjectiveTurret() : 
+   position_(0),
    numPos_(6), 
    busy_(false), 
    initialized_(false),
    sequenceRunning_(false),
+   sequenceIndex_(0),
    sequenceMaxSize_(10)
 {
    SetErrorText(ERR_IN_SEQUENCE, "Error occurred while executing sequence");
@@ -3594,6 +3600,11 @@ posX_um_(0.0),
 posY_um_(0.0),
 timeOutTimer_(0),
 velocity_(10.0), // in mm per second (= um/ms)
+moveDuration_ms_(100),
+startPosX_um_(0.0),
+startPosY_um_(0.),
+targetPosX_um_(0.0),
+targetPosY_um_(0.),
 initialized_(false),
 lowerLimit_(0.0),
 upperLimit_(20000.0)
@@ -3903,6 +3914,7 @@ int DemoShutter::OnState(MM::PropertyBase* pProp, MM::ActionType eAct)
 
       // apply the value
       state_ = pos == 0 ? false : true;
+      GetCoreCallback()->OnShutterOpenChanged(this, state_);
    }
 
    return DEVICE_OK;
diff --git a/DeviceAdapters/DemoCamera/DemoCamera.h b/DeviceAdapters/DemoCamera/DemoCamera.h
index ef351340a..fd4afab77 100644
--- a/DeviceAdapters/DemoCamera/DemoCamera.h
+++ b/DeviceAdapters/DemoCamera/DemoCamera.h
@@ -631,6 +631,7 @@ class DemoShutter : public CShutterBase<DemoShutter>
    {
       state_ = open;
       changedTime_ = GetCurrentMMTime();
+      GetCoreCallback()->OnShutterOpenChanged(this, open);
       return DEVICE_OK;
    }
    int GetOpen(bool& open)
diff --git a/DeviceAdapters/Utilities/DAShutter.cpp b/DeviceAdapters/Utilities/DAShutter.cpp
index 6841e0b7c..6e0e00304 100644
--- a/DeviceAdapters/Utilities/DAShutter.cpp
+++ b/DeviceAdapters/Utilities/DAShutter.cpp
@@ -118,9 +118,12 @@ bool DAShutter::Busy()
 int DAShutter::SetOpen(bool open)
 {
    MM::SignalIO* da = (MM::SignalIO*)GetDevice(DADeviceName_.c_str());
+   int ret = DEVICE_OK;
    if (da != 0)
-      return da->SetGateOpen(open);
-   return DEVICE_OK;
+      ret = da->SetGateOpen(open);
+   if (ret == DEVICE_OK)
+      GetCoreCallback()->OnShutterOpenChanged(this, open);
+   return ret;
 }
 
 int DAShutter::GetOpen(bool& open)
diff --git a/DeviceAdapters/Utilities/MultiShutter.cpp b/DeviceAdapters/Utilities/MultiShutter.cpp
index 79773d308..5cdcb96b8 100644
--- a/DeviceAdapters/Utilities/MultiShutter.cpp
+++ b/DeviceAdapters/Utilities/MultiShutter.cpp
@@ -155,6 +155,7 @@ int MultiShutter::SetOpen(bool open)
       }
    }
    open_ = open;
+   GetCoreCallback()->OnShutterOpenChanged(this, open);
    return DEVICE_OK;
 }
 
diff --git a/MMCore/CoreCallback.cpp b/MMCore/CoreCallback.cpp
index 47405ce4f..c5a24d2d3 100644
--- a/MMCore/CoreCallback.cpp
+++ b/MMCore/CoreCallback.cpp
@@ -674,6 +674,19 @@ int CoreCallback::OnMagnifierChanged(const MM::Device* /* device */)
    return DEVICE_OK;
 }
 
+/**
+ * Handler for Shutter State changes.
+ * 
+ */
+int CoreCallback::OnShutterOpenChanged(const MM::Device* device, bool state)
+{
+   if (core_->externalCallback_) {
+      char label[MM::MaxStrLength];
+      device->GetLabel(label);
+      core_->externalCallback_->onShutterOpenChanged(label, state);
+   }
+   return DEVICE_OK;
+}
 
 
 int CoreCallback::SetSerialProperties(const char* portName,
diff --git a/MMCore/CoreCallback.h b/MMCore/CoreCallback.h
index 1711aea7d..451e8a21b 100644
--- a/MMCore/CoreCallback.h
+++ b/MMCore/CoreCallback.h
@@ -120,6 +120,7 @@ class CoreCallback : public MM::Core
    int OnExposureChanged(const MM::Device* device, double newExposure);
    int OnSLMExposureChanged(const MM::Device* device, double newExposure);
    int OnMagnifierChanged(const MM::Device* device);
+   int OnShutterOpenChanged(const MM::Device* device, bool open);
 
 
    void NextPostedError(int& errorCode, char* pMessage, int maxlen, int& messageLength);
diff --git a/MMCore/MMCore.cpp b/MMCore/MMCore.cpp
index 58d5ded1c..676979c03 100644
--- a/MMCore/MMCore.cpp
+++ b/MMCore/MMCore.cpp
@@ -103,7 +103,7 @@
  * (Keep the 3 numbers on one line to make it easier to look at diffs when
  * merging/rebasing.)
  */
-const int MMCore_versionMajor = 11, MMCore_versionMinor = 9, MMCore_versionPatch = 0;
+const int MMCore_versionMajor = 11, MMCore_versionMinor = 10, MMCore_versionPatch = 0;
 
 
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/MMCore/MMEventCallback.h b/MMCore/MMEventCallback.h
index f02cfc6bc..84bf6beb8 100644
--- a/MMCore/MMEventCallback.h
+++ b/MMCore/MMEventCallback.h
@@ -87,6 +87,11 @@ class MMEventCallback
       std::cout << "onExposureChanged()" << name << " " << newExposure << '\n';
    }
 
+   virtual void onShutterOpenChanged(const char* name, bool open)
+   {
+      std::cout << "onShutterOpenChanged()" << name << " " << open << '\n';
+   }
+
    virtual void onSLMExposureChanged(const char* name, double newExposure)
    {
       std::cout << "onSLMExposureChanged()" << name << " " << newExposure << '\n';
diff --git a/MMDevice/MMDevice.h b/MMDevice/MMDevice.h
index 56ace214a..1e7b1117c 100644
--- a/MMDevice/MMDevice.h
+++ b/MMDevice/MMDevice.h
@@ -28,7 +28,7 @@
 // Header version
 // If any of the class definitions changes, the interface version
 // must be incremented
-#define DEVICE_INTERFACE_VERSION 73
+#define DEVICE_INTERFACE_VERSION 74
 ///////////////////////////////////////////////////////////////////////////////
 
 // N.B.
@@ -1571,6 +1571,10 @@ namespace MM {
        * Magnifiers can use this to signal changes in magnification
        */
       virtual int OnMagnifierChanged(const Device* caller) = 0;
+      /**
+       * Signals that the shutter opened or closed
+       */
+      virtual int OnShutterOpenChanged(const Device* caller, bool open) = 0;
 
       // Deprecated: Return value overflows in ~72 minutes on Windows.
       // Prefer std::chrono::steady_clock for time delta measurements.