diff --git a/src/factory/FieldCreateFactory.cpp b/src/factory/FieldCreateFactory.cpp
index d6d4c33..c4335a6 100644
--- a/src/factory/FieldCreateFactory.cpp
+++ b/src/factory/FieldCreateFactory.cpp
@@ -532,15 +532,6 @@ string Structure::getID() const
 	return id;
 }
 
-FieldConstPtr  Structure::getField(string const & fieldName) const {
-    for(size_t i=0, N=fields.size(); i<N; i++) {
-        if(fieldName==fieldNames[i]) {
-            return fields[i];
-        }
-    }
-    return FieldConstPtr();
-}
-
 size_t Structure::getFieldIndex(string const &fieldName) const {
     size_t numberFields = fields.size();
     for(size_t i=0; i<numberFields; i++) {
@@ -551,6 +542,35 @@ size_t Structure::getFieldIndex(string const &fieldName) const {
     return -1;
 }
 
+FieldConstPtr Structure::getFieldImpl(string const & fieldName, bool throws) const {
+    for(size_t i=0, N=fields.size(); i<N; i++)
+        if(fieldName==fieldNames[i])
+            return fields[i];
+
+    if (throws) {
+        std::stringstream ss;
+        ss << "Failed to get field: "
+           << fieldName << " (not found)";
+        throw std::runtime_error(ss.str());
+    } else {
+        return FieldConstPtr();
+    }
+}
+
+FieldConstPtr Structure::getFieldImpl(size_t fieldOffset, bool throws) const {
+    if (fieldOffset < fields.size())
+        return fields[fieldOffset];
+
+    if (throws) {
+        std::stringstream ss;
+        ss << "Failed to get field with offset "
+           << fieldOffset << " (Invalid offset)";
+        throw std::runtime_error(ss.str());
+    } else {
+        return FieldConstPtr();
+    }
+}
+
 std::ostream& Structure::dump(std::ostream& o) const
 {
     o << format::indent() << getID() << std::endl;
@@ -730,16 +750,6 @@ string Union::getID() const
 	return id;
 }
 
-FieldConstPtr  Union::getField(string const & fieldName) const {
-    size_t numberFields = fields.size();
-    for(size_t i=0; i<numberFields; i++) {
-        FieldConstPtr pfield = fields[i];
-        int result = fieldName.compare(fieldNames[i]);
-        if(result==0) return pfield;
-    }
-    return FieldConstPtr();
-}
-
 size_t Union::getFieldIndex(string const &fieldName) const {
     size_t numberFields = fields.size();
     for(size_t i=0; i<numberFields; i++) {
@@ -750,6 +760,35 @@ size_t Union::getFieldIndex(string const &fieldName) const {
     return -1;
 }
 
+FieldConstPtr Union::getFieldImpl(string const & fieldName, bool throws) const {
+    for(size_t i=0, N=fields.size(); i<N; i++)
+        if(fieldName==fieldNames[i])
+            return fields[i];
+
+    if (throws) {
+        std::stringstream ss;
+        ss << "Failed to get field: "
+           << fieldName << " (not found)";
+        throw std::runtime_error(ss.str());
+    } else {
+        return FieldConstPtr();
+    }
+}
+
+FieldConstPtr Union::getFieldImpl(size_t fieldOffset, bool throws) const {
+    if (fieldOffset < fields.size())
+        return fields[fieldOffset];
+
+    if (throws) {
+        std::stringstream ss;
+        ss << "Failed to get field with offset "
+           << fieldOffset << " (Invalid offset)";
+        throw std::runtime_error(ss.str());
+    } else {
+        return FieldConstPtr();
+    }
+}
+
 std::ostream& Union::dump(std::ostream& o) const
 {
     o << format::indent() << getID() << std::endl;
diff --git a/src/pv/pvIntrospect.h b/src/pv/pvIntrospect.h
index 682914e..99492bd 100644
--- a/src/pv/pvIntrospect.h
+++ b/src/pv/pvIntrospect.h
@@ -719,7 +719,7 @@ public:
      * @return The introspection interface.
      * This will hold a null pointer if the field is not in the structure.
      */
-    FieldConstPtr getField(std::string const &fieldName) const;
+    FieldConstPtr getField(std::string const &fieldName) const {return getFieldImpl(fieldName, false);};
 
     template<typename FT>
     std::tr1::shared_ptr<const FT> getField(std::string const &fieldName) const
@@ -731,13 +731,27 @@ public:
             return std::tr1::shared_ptr<const FT>();
     }
 
+    /**
+     * Get the field for the specified fieldName.
+     * @param fieldName The name of the field to get;
+     * @return The introspection interface.
+     * This will throw a runtime_error exception if the field is not in the structure.
+     */
+    FieldConstPtr getFieldT(std::string const &fieldName) const {return getFieldImpl(fieldName, true);};
+
+    template<typename FT>
+    std::tr1::shared_ptr<const FT> getFieldT(std::string const &fieldName) const
+    {
+        return std::tr1::dynamic_pointer_cast<const FT>(getFieldT(fieldName));
+    }
+
     /**
      * Get the field for the specified fieldName.
      * @param index The index of the field to get;
      * @return The introspection interface.
      * This will hold a null pointer if the field is not in the structure.
      */
-    const FieldConstPtr& getField(std::size_t index) const {return fields.at(index);}
+    FieldConstPtr getField(std::size_t index) const {return getFieldImpl(index, false);}
 
     template<typename FT>
     std::tr1::shared_ptr<const FT> getField(std::size_t index) const
@@ -749,6 +763,20 @@ public:
             return std::tr1::shared_ptr<const FT>();
     }
 
+    /**
+     * Get the field for the specified fieldName.
+     * @param index The index of the field to get;
+     * @return The introspection interface.
+     * This will throw a runtime_error exception if the field is not in the structure.
+     */
+    FieldConstPtr getFieldT(std::size_t index) const {return getFieldImpl(index, true);}
+
+    template<typename FT>
+    std::tr1::shared_ptr<const FT> getFieldT(std::size_t index) const
+    {
+        return std::tr1::dynamic_pointer_cast<const FT>(getFieldT(index));
+    }
+
     /**
      * Get the field index for the specified fieldName.
      * @return The introspection interface.
@@ -790,6 +818,8 @@ private:
     FieldConstPtrArray fields;
     std::string id;
 
+    FieldConstPtr getFieldImpl(const std::string& fieldName, bool throws) const;
+    FieldConstPtr getFieldImpl(const std::size_t fieldOffset, bool throws) const;
     void dumpFields(std::ostream& o) const;
     
     friend class FieldCreate;
@@ -842,7 +872,7 @@ public:
      * @return The introspection interface.
      * This will hold a null pointer if the field is not in the union.
      */
-    FieldConstPtr getField(std::string const &fieldName) const;
+    FieldConstPtr getField(std::string const &fieldName) const {return getFieldImpl(fieldName, false);};
 
     template<typename FT>
     std::tr1::shared_ptr<const FT> getField(std::string const &fieldName) const
@@ -854,13 +884,27 @@ public:
             return std::tr1::shared_ptr<const FT>();
     }
 
+    /**
+     * Get the field for the specified fieldName.
+     * @param fieldName The name of the field to get;
+     * @return The introspection interface.
+     * This will throw a runtime_error exception if the field is not in the union.
+     */
+    FieldConstPtr getFieldT(std::string const &fieldName) const {return getFieldImpl(fieldName, true);};
+
+    template<typename FT>
+    std::tr1::shared_ptr<const FT> getFieldT(std::string const &fieldName) const
+    {
+        return std::tr1::dynamic_pointer_cast<const FT>(getFieldT(fieldName));
+    }
+
     /**
      * Get the field for the specified fieldName.
      * @param index The index of the field to get;
      * @return The introspection interface.
      * This will hold a null pointer if the field is not in the union.
      */
-    FieldConstPtr getField(std::size_t index) const {return fields.at(index);}
+    FieldConstPtr getField(std::size_t index) const {return getFieldImpl(index, false);}
 
     template<typename FT>
     std::tr1::shared_ptr<const FT> getField(std::size_t index) const
@@ -872,6 +916,20 @@ public:
             return std::tr1::shared_ptr<const FT>();
     }
 
+    /**
+     * Get the field for the specified fieldName.
+     * @param index The index of the field to get;
+     * @return The introspection interface.
+     * This will throw a runtime_error exception if the field is not in the union.
+     */
+    FieldConstPtr getFieldT(std::size_t index) const {return getFieldImpl(index, true);}
+
+    template<typename FT>
+    std::tr1::shared_ptr<const FT> getFieldT(std::size_t index) const
+    {
+        return std::tr1::dynamic_pointer_cast<const FT>(getFieldT(index));
+    }
+
     /**
      * Get the field index for the specified fieldName.
      * @return The introspection interface.
@@ -929,7 +987,9 @@ private:
    StringArray fieldNames;
    FieldConstPtrArray fields;
    std::string id;
-   
+
+   FieldConstPtr getFieldImpl(const std::string& fieldName, bool throws) const;
+   FieldConstPtr getFieldImpl(const std::size_t fieldOffset, bool throws) const;
    void dumpFields(std::ostream& o) const;
 
    friend class FieldCreate;
diff --git a/testApp/pv/testIntrospect.cpp b/testApp/pv/testIntrospect.cpp
index 4f02086..9a74203 100644
--- a/testApp/pv/testIntrospect.cpp
+++ b/testApp/pv/testIntrospect.cpp
@@ -146,6 +146,28 @@ static void testStructure()
     testOk1(struct1->getFieldName(0)==names1[0]);
     testOk1(struct1->getFieldName(1)==names1[1]);
 
+    testOk1(struct1->getField("nonexistent").get()==NULL);
+    testOk1(struct1->getField(9999).get()==NULL);
+
+    testOk1(struct1->getFieldT("innerA")==fields1[0]);
+    testOk1(struct1->getFieldT("innerB")==fields1[1]);
+    testOk1(struct1->getFieldT(0)==fields1[0]);
+    testOk1(struct1->getFieldT(1)==fields1[1]);
+
+    try {
+        FieldConstPtr field(struct1->getFieldT("nonexistent"));
+        testFail("missing required exception");
+    } catch (std::runtime_error& e) {
+        testPass("caught expected exception: %s", e.what());
+    }
+
+    try {
+        FieldConstPtr field(struct1->getFieldT(9999));
+        testFail("missing required exception");
+    } catch (std::runtime_error& e) {
+        testPass("caught expected exception: %s", e.what());
+    }
+
     testOk1(struct1->getID() == Structure::DEFAULT_ID);
 
     testOk1(fields1 == struct1->getFields()); // vector equality
@@ -190,6 +212,28 @@ static void testUnion()
     testOk1(union1->getFieldName(0)==names1[0]);
     testOk1(union1->getFieldName(1)==names1[1]);
 
+    testOk1(union1->getField("nonexistent").get()==NULL);
+    testOk1(union1->getField(9999).get()==NULL);
+
+    testOk1(union1->getFieldT("innerA")==fields1[0]);
+    testOk1(union1->getFieldT("innerB")==fields1[1]);
+    testOk1(union1->getFieldT(0)==fields1[0]);
+    testOk1(union1->getFieldT(1)==fields1[1]);
+
+    try {
+        FieldConstPtr field(union1->getFieldT("nonexistent"));
+        testFail("missing required exception");
+    } catch (std::runtime_error& e) {
+        testPass("caught expected exception: %s", e.what());
+    }
+
+    try {
+        FieldConstPtr field(union1->getFieldT(9999));
+        testFail("missing required exception");
+    } catch (std::runtime_error& e) {
+        testPass("caught expected exception: %s", e.what());
+    }
+
     testOk1(union1->getID() == Union::DEFAULT_ID);
 
     testOk1(fields1 == union1->getFields()); // vector equality
@@ -311,7 +355,7 @@ static void testMapping()
 
 MAIN(testIntrospect)
 {
-    testPlan(326);
+    testPlan(342);
     fieldCreate = getFieldCreate();
     pvDataCreate = getPVDataCreate();
     standardField = getStandardField();