diff --git a/documentation/pvDataCpp.html b/documentation/pvDataCpp.html
index 868e6d7..baf7a71 100644
--- a/documentation/pvDataCpp.html
+++ b/documentation/pvDataCpp.html
@@ -13,7 +13,7 @@
 
 <p>TODO</p>
 <ul>
-  <li>rename epicsException to exception. Do we want assert under pvData? I
+  <li>rename epicsException to Exception. Do we want assert under pvData? I
     think yes. Can it generate stack trace?</li>
   <li>pvMiscBitSetUtil has not been tested.</li>
   <li>Change all throw statements so that they generated stack trace.</li>
diff --git a/pvDataApp/Makefile b/pvDataApp/Makefile
index 3db7ce6..75d4a47 100644
--- a/pvDataApp/Makefile
+++ b/pvDataApp/Makefile
@@ -89,6 +89,8 @@ LIBSRCS += bitSetUtil.cpp
 
 SRC_DIRS += $(PVDATA)/monitor
 INC += monitor.h
+INC += monitorQueue.h
+LIBSRCS += monitorQueue.cpp
 
 
 LIBRARY=pvData
diff --git a/pvDataApp/factory/Convert.cpp b/pvDataApp/factory/Convert.cpp
index 1397e63..e4a9a40 100644
--- a/pvDataApp/factory/Convert.cpp
+++ b/pvDataApp/factory/Convert.cpp
@@ -315,49 +315,49 @@ void Convert::copyScalar(PVScalar *from, PVScalar *to)
                 PVBoolean *dataTo = static_cast<PVBoolean*>(to);
                 dataTo->put(value);
             }
-            break;
+            return;
         }
     case pvByte : {
             PVByte *data = static_cast<PVByte*>(from);
             int8 value = data->get();
             convert->fromByte(to,value);
-            break;
+            return;
         }
     case pvShort : {
             PVShort *data = static_cast<PVShort*>(from);
             short value = data->get();
             convert->fromShort(to,value);
-            break;
+            return;
         } 
     case pvInt :{
             PVInt *data = static_cast<PVInt*>(from);
             int value = data->get();
             convert->fromInt(to,value);
-            break;
+            return;
         }    
     case pvLong : {
             PVLong *data = static_cast<PVLong*>(from);
             long value = data->get();
             convert->fromLong(to,value);
-            break;
+            return;
         }  
     case pvFloat : {
             PVFloat *data = static_cast<PVFloat*>(from);
             float value = data->get();
             convert->fromFloat(to,value);
-            break;
+            return;
         }     
     case pvDouble : {
             PVDouble *data = static_cast<PVDouble*>(from);
             double value = data->get();
             convert->fromDouble(to,value);
-            break;
+            return;
         }  
     case pvString: {
             PVString *data = static_cast<PVString*>(from);
             String value = data->get();
             convert->fromString(to,value);
-            break;
+            return;
         }
     }
     String message("Convert::copyScalar should never get here");
diff --git a/pvDataApp/factory/StandardPVField.cpp b/pvDataApp/factory/StandardPVField.cpp
index 1ba7cb1..c1254f2 100644
--- a/pvDataApp/factory/StandardPVField.cpp
+++ b/pvDataApp/factory/StandardPVField.cpp
@@ -223,7 +223,6 @@ PVStructure * StandardPVField::enumeratedValue(PVStructure *parent,
     PVStringArray *pvChoices = static_cast<PVStringArray *>(pvScalarArray);
     pvChoices->put(0,number,choices,0);
     return pvStructure;
-    return pvDataCreate->createPVStructure(parent,field);
 }
 
 PVStructure * StandardPVField::alarm(PVStructure *parent)
diff --git a/pvDataApp/misc/queueVoid.cpp b/pvDataApp/misc/queueVoid.cpp
index c263758..f94ee1f 100644
--- a/pvDataApp/misc/queueVoid.cpp
+++ b/pvDataApp/misc/queueVoid.cpp
@@ -92,7 +92,7 @@ QueueElementVoid * QueueVoid::getFree()
 void QueueVoid::setUsed(QueueElementVoid *queueElement)
 {
     if(queueElement!=array[nextSetUsed++]) {
-        throw std::logic_error(String("not correcect queueElement"));
+        throw std::logic_error(String("not correct queueElement"));
     }
     numberUsed++;
     if(nextSetUsed>=number) nextSetUsed = 0;
diff --git a/pvDataApp/monitor/monitor.h b/pvDataApp/monitor/monitor.h
index 0ed7b68..5454329 100644
--- a/pvDataApp/monitor/monitor.h
+++ b/pvDataApp/monitor/monitor.h
@@ -9,86 +9,39 @@
 
 #include <status.h>
 #include <destroyable.h>
+#include <sharedPtr.h>
+#include <pvData.h>
 
 namespace epics { namespace pvData { 
 
-    /**
-     * Class instance representing monitor element.
-     * @author mrk
-     */
-    class MonitorElement {
-        public:
-        /**
-         * Get the PVStructure.
-         * @return The PVStructure.
-         */
-        virtual PVStructure* getPVStructure() = 0;
-        /**
-         * Get the bitSet showing which fields have changed.
-         * @return The bitSet.
-         */
-        virtual BitSet* getChangedBitSet() = 0;
-        /**
-         * Get the bitSet showing which fields have been changed more than once.
-         * @return The bitSet.
-         */
-        virtual BitSet* getOverrunBitSet() = 0;
-    };
-    
-    
-    /**
-     * Interface for Monitor.
-     * @author mrk
-     */
-    class Monitor : public Destroyable, private NoDefaultMethods {
-        public:
-        /**
-         * Start monitoring.
-         * @return completion status.
-         */
-        virtual Status start() = 0;
-        /**
-         * Stop Monitoring.
-         * @return completion status.
-         */
-        virtual Status stop() = 0;
-        /**
-         * If monitor has occurred return data.
-         * @return monitorElement for modified data on null if no monitors have occurred.
-         */
-        virtual MonitorElement* poll() = 0;
-        /**
-         * Release a MonitorElement that was returned by poll.
-         * @param monitorElement
-         */
-        virtual void release(MonitorElement* monitorElement) = 0;
-    };
-    
-    
-    /**
-     * Requester for ChannelMonitor.
-     * @author mrk
-     */
-    class MonitorRequester : public virtual Requester {
-        public:
-        /**
-         * The client and server have both completed the createMonitor request.
-         * @param status Completion status.
-         * @param monitor The monitor
-         * @param structure The structure defining the data.
-         */
-        virtual void monitorConnect(const Status &status, Monitor* monitor, Structure* structure) = 0;
-        /**
-         * A monitor event has occurred. The requester must call Monitor.poll to get data.
-         * @param monitor The monitor.
-         */
-        virtual void monitorEvent(Monitor* monitor) = 0;
-        /**
-         * The data source is no longer available.
-         * @param monitor The monitor.
-         */
-        virtual void unlisten(Monitor* monitor) = 0;
-    };
+class MonitorElement {
+public:
+    MonitorElement(){}
+    virtual ~MonitorElement(){}
+    virtual PVStructure* getPVStructure() = 0;
+    virtual BitSet* getChangedBitSet() = 0;
+    virtual BitSet* getOverrunBitSet() = 0;
+};
+
+class Monitor : public virtual Destroyable{
+    public:
+    Monitor(){}
+    virtual ~Monitor(){}
+    virtual Status start() = 0;
+    virtual Status stop() = 0;
+    virtual MonitorElement* poll() = 0;
+    virtual void release(MonitorElement* monitorElement) = 0;
+};
+
+class MonitorRequester : public virtual Requester {
+    public:
+    MonitorRequester() {}
+    virtual ~MonitorRequester() {}
+    virtual void monitorConnect(
+        const Status &status, Monitor* monitor, StructureConstPtr structure) = 0;
+    virtual void monitorEvent(Monitor* monitor) = 0;
+    virtual void unlisten(Monitor* monitor) = 0;
+};
 
 }}
 #endif  /* MONITOR_H */
diff --git a/pvDataApp/monitor/monitorQueue.cpp b/pvDataApp/monitor/monitorQueue.cpp
new file mode 100644
index 0000000..ef53c56
--- /dev/null
+++ b/pvDataApp/monitor/monitorQueue.cpp
@@ -0,0 +1,146 @@
+/* monitorQueue.cpp */
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * EPICS pvDataCPP is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+/* Marty Kraimer 2011.03 */
+#include <bitSet.h>
+
+#include "monitorQueue.h"
+
+
+namespace epics { namespace pvData { 
+
+typedef QueueElement<MonitorElement> MonitorQueueElement;
+
+class MonitorElementImpl : public MonitorElement {
+public:
+    MonitorElementImpl(PVStructure *pvStructure);
+    ~MonitorElementImpl(){}
+    virtual PVStructure* getPVStructure();
+    virtual BitSet* getChangedBitSet();
+    virtual BitSet* getOverrunBitSet();
+    void setQueueElement(MonitorQueueElement *queueElement);
+    MonitorQueueElement *getQueueElement();
+private:
+    PVStructure *pvStructure;
+    std::auto_ptr<BitSet> changedBitSet;
+    std::auto_ptr<BitSet> overrunBitSet;
+    MonitorQueueElement *queueElement;
+};
+
+MonitorElementImpl::MonitorElementImpl(PVStructure *pvStructure)
+: pvStructure(pvStructure),
+  changedBitSet(std::auto_ptr<BitSet>(new BitSet(pvStructure->getNumberFields()))),
+  overrunBitSet(std::auto_ptr<BitSet>(new BitSet(pvStructure->getNumberFields()))),
+  queueElement(0)
+{}
+
+PVStructure* MonitorElementImpl::getPVStructure()
+{
+    return pvStructure;
+}
+
+BitSet* MonitorElementImpl::getChangedBitSet()
+{
+    return changedBitSet.get();
+}
+
+BitSet* MonitorElementImpl::getOverrunBitSet()
+{
+    return overrunBitSet.get();
+}
+
+void MonitorElementImpl::setQueueElement(MonitorQueueElement *queueElement)
+{
+    this->queueElement = queueElement;
+}
+
+MonitorQueueElement *MonitorElementImpl::getQueueElement()
+{
+    return queueElement;
+}
+
+MonitorQueue::MonitorQueue(MonitorElement** elements,int number)
+: number(number),
+  elements(elements),
+  queue(new Queue<MonitorElement>(elements,number))
+{
+    if(number<2) {
+         throw std::logic_error(String("queueSize must be >=2"));
+    }
+    MonitorQueueElement  *queueElement;
+    for(int i=0; i<number;i++) {
+        queueElement = queue->getFree();
+        MonitorElementImpl *temp = 
+            static_cast<MonitorElementImpl*>(queueElement->getObject());
+        temp->setQueueElement(queueElement);
+        queue->setUsed(queueElement);
+        queue->releaseUsed(queueElement);
+    }
+}
+
+MonitorQueue::~MonitorQueue()
+{
+    delete queue;
+    for(int i=0; i<number; i++) {
+        delete elements[i];
+    }
+    delete[] elements;
+}
+
+MonitorElement** MonitorQueue::createElements(PVStructurePtrArray array,int number)
+{
+    MonitorElement** elements = new MonitorElement*[number];
+    for(int i=0; i<number; i++) {
+        elements[i] = new MonitorElementImpl(array[i]);
+    }
+    return elements;
+}
+
+void MonitorQueue::clear()
+{
+    queue->clear();
+}
+
+int MonitorQueue::getNumberFree()
+{
+    return queue->getNumberFree();
+}
+
+int MonitorQueue::capacity()
+{
+    return number;
+}
+
+MonitorElement * MonitorQueue::getFree()
+{
+    MonitorQueueElement *queueElement = queue->getFree();
+    if(queueElement==0) return 0;
+    return queueElement->getObject();
+}
+
+void MonitorQueue::setUsed(MonitorElement * element)
+{
+    MonitorElementImpl *temp = static_cast<MonitorElementImpl*>(element);
+    MonitorQueueElement *queueElement = temp->getQueueElement();
+    queue->setUsed(temp->getQueueElement());
+}
+
+MonitorElement * MonitorQueue::getUsed()
+{
+    MonitorQueueElement *queueElement = queue->getUsed();
+    if(queueElement==0) return 0;
+    return queueElement->getObject();
+}
+
+void MonitorQueue::releaseUsed(MonitorElement * element)
+{
+    MonitorElementImpl *temp = static_cast<MonitorElementImpl*>(element);
+    queue->releaseUsed(temp->getQueueElement());
+}
+
+
+}}
+
diff --git a/pvDataApp/monitor/monitorQueue.h b/pvDataApp/monitor/monitorQueue.h
new file mode 100644
index 0000000..4ba68bc
--- /dev/null
+++ b/pvDataApp/monitor/monitorQueue.h
@@ -0,0 +1,42 @@
+/* monitorQueue.h */
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * EPICS pvDataCPP is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+/* Marty Kraimer 2011.03 */
+#ifndef MONITORQUEUE_H
+#define MONITORQUEUE_H
+#include <string>
+#include <stdexcept>
+#include <memory>
+#include <vector>
+
+#include <pvData.h>
+#include <monitor.h>
+#include <queue.h>
+#include <sharedPtr.h>
+
+namespace epics { namespace pvData { 
+
+class MonitorQueue {
+public:
+    MonitorQueue(MonitorElement** elements,int number);
+    ~MonitorQueue();
+    static MonitorElement** createElements(PVStructurePtrArray array,int number);
+    void clear();
+    int getNumberFree();
+    int capacity();
+    MonitorElement *getFree();
+    void setUsed(MonitorElement * element);
+    MonitorElement * getUsed();
+    void releaseUsed(MonitorElement * element);
+private:
+    int number;
+    MonitorElement ** elements;
+    Queue<MonitorElement> *queue;
+};
+
+}}
+
+#endif  /* MONITORQUEUE_H */