diff --git a/jfj-combined/include/JfjFrameCache.hpp b/jfj-combined/include/FrameCache.hpp
similarity index 89%
rename from jfj-combined/include/JfjFrameCache.hpp
rename to jfj-combined/include/FrameCache.hpp
index 609048d..8b7c426 100644
--- a/jfj-combined/include/JfjFrameCache.hpp
+++ b/jfj-combined/include/FrameCache.hpp
@@ -12,6 +12,8 @@
 #include "../../core-buffer/include/formats.hpp"
 #include "Watchdog.hpp"
 
+#define MAX_FIFO_LENGTH 32
+
 
 /** Frame Cache
 
@@ -39,9 +41,8 @@ public:
         // Initialize buffer metadata
         for(auto& it: m_buffer){ memset(&it.meta, 0, sizeof(it.meta)); }
 
-
+        // Initialize the watchdog
         std::function<void()> wd_callback = std::bind(&FrameCache::flush_all, this);
-
         m_watchdog = new Watchdog(500, wd_callback);
         m_watchdog->Start();
 
@@ -83,8 +84,9 @@ public:
 
         // Queue for draining
         if(m_fill[idx]==m_MOD-1){
-            // std::cout << "Complete frame at " << idx << "\t(queued for draining)\tqueue size: " << drain_queue.size() << std::endl;
-            drain_queue.push_back(idx);
+            if(m_fill.size() > MAX_FIFO_LENGTH) {
+                m_drain_queue.push_back(idx);
+            }
         }
     }
 
@@ -128,13 +130,16 @@ protected:
     }
 
     /** Drain loop
-    Flushes a valid cache line and invalidates the associated buffer.
-    NOTE : It does not lock, that must be done externally!        **/
+
+    Flushes queued frames from the cache buffer and invalidates line.
+    It also locks the frame for the duration of flushing!        **/
     void drain_loop(){
         while(true){
-            if(!drain_queue.empty()){
-                uint32_t idx = drain_queue.front();
-                drain_queue.pop_front();
+            if(!m_drain_queue.empty()){
+                uint32_t idx = m_drain_queue.front();
+                m_drain_queue.pop_front();
+                // Lock and flush the frame
+                std::unique_lock<std::shared_mutex> p_guard(m_lock[idx]);
                 flush_line(idx);
             } else {
                 std::this_thread::sleep_for(std::chrono::milliseconds(2));
@@ -159,7 +164,7 @@ protected:
     /** Watchdog timer and flush queue **/
     Watchdog *m_watchdog;
      std::thread m_drainer;
-    std::deque<uint32_t> drain_queue;
+    std::deque<uint32_t> m_drain_queue;
 
 };
 
diff --git a/jfj-combined/include/JfjFrameStats.hpp b/jfj-combined/include/FrameStats.hpp
similarity index 100%
rename from jfj-combined/include/JfjFrameStats.hpp
rename to jfj-combined/include/FrameStats.hpp
diff --git a/jfj-combined/include/JfjFrameWorker.hpp b/jfj-combined/include/FrameWorker.hpp
similarity index 100%
rename from jfj-combined/include/JfjFrameWorker.hpp
rename to jfj-combined/include/FrameWorker.hpp
diff --git a/jfj-combined/src/main.cpp b/jfj-combined/src/main.cpp
index 1006f1d..d8d17a1 100644
--- a/jfj-combined/src/main.cpp
+++ b/jfj-combined/src/main.cpp
@@ -14,12 +14,13 @@ int main (int argc, char *argv[]) {
     if (argc != 2) {
         std::cout << "\nUsage: jf_buffer_writer [detector_json_filename]\n";
         std::cout << "\tdetector_json_filename: detector config file path." << std::endl;
+        std::cout << "\tZMQ publisher port:     5200 (high data rate)" << std::endl;
         exit(-1);
     }
     const auto config = BufferUtils::read_json_config(std::string(argv[1]));
 
 
-    std::cout << "Creating ZMQ socket..." << std::endl;
+    std::cout << "Creating ZMQ sockets..." << std::endl;
     ZmqImagePublisher pub("*", 5200, 2);
     // ... and extracting sender function
     std::function<void(ImageBinaryFormat&)> zmq_publish =
diff --git a/jfj-combined/test/SimulatedZmqReceiver.cpp b/jfj-combined/test/SimulatedZmqReceiver.cpp
deleted file mode 100644
index 499785d..0000000
--- a/jfj-combined/test/SimulatedZmqReceiver.cpp
+++ /dev/null
@@ -1,51 +0,0 @@
-//
-//  Weather update client in C++
-//  Connects SUB socket to tcp://localhost:5556
-//  Collects weather updates and finds avg temp in zipcode
-//
-
-#include <zmq.hpp>
-#include <iostream>
-#include <sstream>
-
-int main (int argc, char *argv[]){
-    if (argc != 2) {
-        std::cout << "\nERROR\nUsage: jf_buffer_writer [zmq_port]\n";
-        exit(-1);
-    }
-
-    int zmq_port = atoi(argv[1]);
-    std::string addr("tcp://localhost:" + std::to_string(zmq_port));
-    
-    zmq::context_t context (1);
-
-    //  Socket to talk to server
-    std::cout << "Subscribing to server...\n" << std::endl;
-    zmq::socket_t subscriber (context, ZMQ_SUB);
-    subscriber.connect(addr.c_str());
-
-    //  Subscribe to IMAGEDATA
-	const char *filter = "IMAGEDATA";
-    subscriber.setsockopt(ZMQ_SUBSCRIBE, filter, strlen (filter));
-
-    //  Process 100 updates
-    int num_img = 0;
-    long total_temp = 0;
-    zmq::message_t msg_topic;
-    zmq::message_t msg_meta;
-    zmq::message_t msg_image;
-    std::cout << "I'm listening...\n" << std::endl;
-    for (int idx = 0; idx < 100000; idx++) {
-        subscriber.recv(&msg_topic);
-        if(msg_topic.size()==strlen(filter)){
-            subscriber.recv(&msg_meta);
-            subscriber.recv(&msg_image);
-            num_img++;
-        }
-
-        if(idx%500==0){ 
-            std::cout << "Received " << idx << " (at size " << msg_image.size() << " )\t Received: " << num_img << std::endl;
-        }
-    }
-    return 0;
-}
diff --git a/jfj-combined/test/SimulatedDetector.cpp b/jfj-combined/test/mock/SimulatedDetector.cpp
similarity index 100%
rename from jfj-combined/test/SimulatedDetector.cpp
rename to jfj-combined/test/mock/SimulatedDetector.cpp
diff --git a/jfj-combined/test/dummy_detector.json b/jfj-combined/test/mock/dummy_detector.json
similarity index 100%
rename from jfj-combined/test/dummy_detector.json
rename to jfj-combined/test/mock/dummy_detector.json
diff --git a/jfj-combined/test/test_Watchdog.cpp b/jfj-combined/test/test_Watchdog.cpp
new file mode 100644
index 0000000..df18012
--- /dev/null
+++ b/jfj-combined/test/test_Watchdog.cpp
@@ -0,0 +1,51 @@
+#include "gtest/gtest.h"
+#include "Watchdog.hpp"
+
+#include <thread>
+#include <chrono>
+#include <future>
+
+using namespace std;
+
+
+uint64_t tick_counter = 0;
+// Dummy callback to increase tick counter
+void mock_callback(){
+    tick_counter++;
+};
+
+
+TEST(WatchdogTimer, timer_test){
+    Watchdog wDog(100, &mock_callback);
+
+    // Free running
+    wDog.Start();
+    std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    ASSERT_EQ(tick_counter, 0);
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    ASSERT_EQ(tick_counter, 5);
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    ASSERT_EQ(tick_counter, 10);
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    ASSERT_EQ(tick_counter, 15);
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    ASSERT_EQ(tick_counter, 20);
+
+    // Test Stop()
+    wDog.Stop();
+    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    ASSERT_EQ(tick_counter, 20);
+
+    // Test Kick()
+    tick_counter = 0;
+    wDog.Start();
+    std::this_thread::sleep_for(std::chrono::milliseconds(250));
+    ASSERT_EQ(tick_counter, 2);
+    for(int ii=0; ii<20 ii++){
+        wDog.Kick();
+        ASSERT_EQ(tick_counter, 2);
+        std::this_thread::sleep_for(std::chrono::milliseconds(50));
+    }
+    std::this_thread::sleep_for(std::chrono::milliseconds(150));
+    ASSERT_EQ(tick_counter, 4);
+}
diff --git a/zmq-receiver/src/SimulatedZmqReceiver.cpp b/zmq-receiver/src/SimulatedZmqReceiver.cpp
deleted file mode 100644
index 499785d..0000000
--- a/zmq-receiver/src/SimulatedZmqReceiver.cpp
+++ /dev/null
@@ -1,51 +0,0 @@
-//
-//  Weather update client in C++
-//  Connects SUB socket to tcp://localhost:5556
-//  Collects weather updates and finds avg temp in zipcode
-//
-
-#include <zmq.hpp>
-#include <iostream>
-#include <sstream>
-
-int main (int argc, char *argv[]){
-    if (argc != 2) {
-        std::cout << "\nERROR\nUsage: jf_buffer_writer [zmq_port]\n";
-        exit(-1);
-    }
-
-    int zmq_port = atoi(argv[1]);
-    std::string addr("tcp://localhost:" + std::to_string(zmq_port));
-    
-    zmq::context_t context (1);
-
-    //  Socket to talk to server
-    std::cout << "Subscribing to server...\n" << std::endl;
-    zmq::socket_t subscriber (context, ZMQ_SUB);
-    subscriber.connect(addr.c_str());
-
-    //  Subscribe to IMAGEDATA
-	const char *filter = "IMAGEDATA";
-    subscriber.setsockopt(ZMQ_SUBSCRIBE, filter, strlen (filter));
-
-    //  Process 100 updates
-    int num_img = 0;
-    long total_temp = 0;
-    zmq::message_t msg_topic;
-    zmq::message_t msg_meta;
-    zmq::message_t msg_image;
-    std::cout << "I'm listening...\n" << std::endl;
-    for (int idx = 0; idx < 100000; idx++) {
-        subscriber.recv(&msg_topic);
-        if(msg_topic.size()==strlen(filter)){
-            subscriber.recv(&msg_meta);
-            subscriber.recv(&msg_image);
-            num_img++;
-        }
-
-        if(idx%500==0){ 
-            std::cout << "Received " << idx << " (at size " << msg_image.size() << " )\t Received: " << num_img << std::endl;
-        }
-    }
-    return 0;
-}
diff --git a/zmq-receiver/src/main.cpp b/zmq-receiver/src/main.cpp
index 83c5dc9..5c6470c 100644
--- a/zmq-receiver/src/main.cpp
+++ b/zmq-receiver/src/main.cpp
@@ -62,7 +62,6 @@ int main (int argc, char *argv[]){
     for (int idx = 0; idx < 100000; idx++) {
         // ZMQ guarantees full delivery of multipart massages!
         // Packets are sent as three part messages:  topic + meta + data
-        // Blocks until recv succesfull!
         subscriber.recv(&msg_topic, 0);
         subscriber.recv(&msg_meta, 0);
         subscriber.recv(&msg_data, 0);