diff --git a/bus_protocols/isotp_handler.cpp b/bus_protocols/isotp_handler.cpp
index 3dbcfd8..5d8e559 100644
--- a/bus_protocols/isotp_handler.cpp
+++ b/bus_protocols/isotp_handler.cpp
@@ -18,6 +18,8 @@ ISOTP_HANDLER::ISOTP_HANDLER()
 {
     useExtendedAddressing = false;
     isReceiving = false;
+
+    connect(&frameTimer, SIGNAL(timeout()), this, SLOT(frameTimerTick()));
 }
 
 void ISOTP_HANDLER::setExtendedAddressing(bool mode)
@@ -61,7 +63,7 @@ void ISOTP_HANDLER::sendISOTPFrame(int bus, int ID, QVector<unsigned char> data)
         for (int i = 0; i < frame.data[0]; i++) frame.data[i + 1] = data[i];
         CANConManager::getInstance()->sendFrame(frame);
     }
-    else //need to send a multi-part ISO_TP message - no flow control possible right now. TODO - Add flow control
+    else //need to send a multi-part ISO_TP message - Respects timing and frame number based flow control
     {
         frame.bus = bus;
         frame.ID = ID;
@@ -72,6 +74,11 @@ void ISOTP_HANDLER::sendISOTPFrame(int bus, int ID, QVector<unsigned char> data)
         frame.data[1] = data.length() & 0xFF;
         for (int i = 0; i < 6; i++) frame.data[2 + i] = data[currByte++];
         CANConManager::getInstance()->sendFrame(frame);
+        //Queue up the rest of the frames
+        waitingForFlow = true;
+        frameTimer.setInterval(200); //wait a while for the flow frame to come in
+        frameTimer.setTimerType(Qt::PreciseTimer);
+        frameTimer.start();
         while (currByte < data.length())
         {
             for (int b = 0; b < 8; b++) frame.data[b] = 0xAA;
@@ -81,7 +88,8 @@ void ISOTP_HANDLER::sendISOTPFrame(int bus, int ID, QVector<unsigned char> data)
             if (bytesToGo > 7) bytesToGo = 7;
             for (int i = 0; i < bytesToGo; i++) frame.data[1 + i] = data[currByte++];
             frame.len = 8;
-            CANConManager::getInstance()->sendFrame(frame);
+            sendingFrames.append(frame);
+            //CANConManager::getInstance()->sendFrame(frame);
         }
     }
 }
@@ -100,7 +108,7 @@ void ISOTP_HANDLER::updatedFrames(int numFrames)
     {
         for (int i = modelFrames->count() - numFrames; i < modelFrames->count(); i++)
         {
-            //processFrame(modelFrames->at(i));
+            //processFrame(modelFrames->at(i));  //accepting these frames in rapidFrames instead
         }
     }
 }
@@ -114,7 +122,9 @@ void ISOTP_HANDLER::rapidFrames(const CANConnection* conn, const QVector<CANFram
 
     foreach(const CANFrame& thisFrame, pFrames)
     {
-        processFrame(thisFrame);
+        //only process frames that we've marked are ISOTP frames
+        //unless processAll is true
+        if (isoIDs[thisFrame.ID] || processAll) processFrame(thisFrame);
     }
 }
 
@@ -220,7 +230,30 @@ void ISOTP_HANDLER::processFrame(const CANFrame &frame)
             emit newISOMessage(*pMsg);
         }
         break;
-    case 3: //flow control messages -ignored for now
+    case 3: //flow control messages
+        switch (frameLen) //actually flow control type in this case
+        {
+        case 0: //continue to send frames but maybe change inter-frame delay
+            waitingForFlow = false;
+            //data[1] contains number of frames to send before waiting for next flow control
+            framesUntilFlow = frame.data[1];
+            if (framesUntilFlow == 0) framesUntilFlow = -1; //-1 means don't count frames and just keep going
+            //data[2] contains the interframe delay to use (0xF1 through 0xF9 are special through)
+            if (frame.data[2] < 0xF1) frameTimer.start(frame.data[2]); //set proper delay between frames
+            else frameTimer.start(1); //can't do sub-millisecond sending with this code so just use 1ms timing
+            break;
+        case 1: //wait - do not send any more frames until other side says so
+            waitingForFlow = true;
+            frameTimer.stop(); //quit sending frames for now
+            break;
+        case 2: //overflow or abort. Assume this means abort and quit sending
+            frameTimer.stop();
+            sendingFrames.clear();
+            waitingForFlow = false;
+            break;
+        }
+        waitingForFlow = false;
+
         break;
     }
 }
@@ -231,13 +264,7 @@ void ISOTP_HANDLER::checkNeedFlush(uint64_t ID)
     {
         if (messageBuffer[i].ID == ID)
         {
-            //warning... this code will work for direct signals as emit turns into a function call
-            //and thus the other side will have time to do its processing before control returns
-            //and we delete the message on our side. But, if this code were used cross thread the
-            //emit would be a queued message instead and control would immediately return
-            //here and then the message would be deleted before being delivered.
-            //To fix that the message would have to be passed by value instead which I'd like to avoid.
-            //Thus, don't use this across threads unless you like to debug strange issues.
+            //used to pass by reference but now newISOMessage should pass by value which makes it easier to use cross thread
             qDebug() << "Flushing a partial frame";
             emit newISOMessage(messageBuffer[i]);
             messageBuffer.removeAt(i);
@@ -245,3 +272,52 @@ void ISOTP_HANDLER::checkNeedFlush(uint64_t ID)
         }
     }
 }
+
+void ISOTP_HANDLER::frameTimerTick()
+{
+    CANFrame frame;
+    if (!waitingForFlow)
+    {
+        if (!sendingFrames.isEmpty())
+        {
+            frame = sendingFrames.takeFirst();
+            CANConManager::getInstance()->sendFrame(frame);
+            if (framesUntilFlow > -1) framesUntilFlow--;
+            if (framesUntilFlow == 0) //stop sending and wait for another flow control message
+            {
+                frameTimer.stop(); //we absolutely will not send anything until other side says to.
+                waitingForFlow = true;
+            }
+        }
+        else //no more frames to send
+        {
+            frameTimer.stop();
+        }
+    }
+    else //while waiting for a flow frame we didn't get one during timeout period. Try to send anyway with default timeout
+    {
+        waitingForFlow = false;
+        frameTimer.setInterval(20); //pretty slow sending which should be OK as a default
+    }
+}
+
+void ISOTP_HANDLER::setProcessAll(bool state)
+{
+    processAll = state;
+}
+
+void ISOTP_HANDLER::addID(uint32_t id)
+{
+    isoIDs[id] = true;
+}
+
+void ISOTP_HANDLER::removeID(uint32_t id)
+{
+    isoIDs.remove(id);
+}
+
+void ISOTP_HANDLER::clearAllIDs()
+{
+    isoIDs.clear();
+}
+
diff --git a/bus_protocols/isotp_handler.h b/bus_protocols/isotp_handler.h
index 5d22c21..cce3628 100644
--- a/bus_protocols/isotp_handler.h
+++ b/bus_protocols/isotp_handler.h
@@ -4,6 +4,7 @@
 #include <Qt>
 #include <QObject>
 #include <QDebug>
+#include <QTimer>
 #include "can_structs.h"
 #include "mainwindow.h"
 #include "canframemodel.h"
@@ -19,19 +20,30 @@ public:
     static ISOTP_HANDLER* getInstance();
     void setReception(bool mode); //set whether to accept and forward frames or not
     void sendISOTPFrame(int bus, int ID, QVector<unsigned char> data);
+    void setProcessAll(bool state);
+    void addID(uint32_t id);
+    void removeID(uint32_t id);
+    void clearAllIDs();
 
 public slots:
     void updatedFrames(int);
     void rapidFrames(const CANConnection* conn, const QVector<CANFrame>& pFrames);
+    void frameTimerTick();
 
 signals:
-    void newISOMessage(ISOTP_MESSAGE &msg);
+    void newISOMessage(ISOTP_MESSAGE msg);
 
 private:
     QList<ISOTP_MESSAGE> messageBuffer;
+    QList<CANFrame> sendingFrames;
+    QMap<uint32_t, bool> isoIDs;
     const QVector<CANFrame> *modelFrames;
     bool useExtendedAddressing;
     bool isReceiving;
+    bool waitingForFlow;
+    int framesUntilFlow;
+    bool processAll;
+    QTimer frameTimer;
 
     void processFrame(const CANFrame &frame);
     void checkNeedFlush(uint64_t ID);
diff --git a/bus_protocols/uds_handler.cpp b/bus_protocols/uds_handler.cpp
index 112eb06..9aa4070 100644
--- a/bus_protocols/uds_handler.cpp
+++ b/bus_protocols/uds_handler.cpp
@@ -150,7 +150,7 @@ UDS_HANDLER::UDS_HANDLER()
     useExtendedAddressing = false;
 }
 
-void UDS_HANDLER::gotISOTPFrame(ISOTP_MESSAGE &msg)
+void UDS_HANDLER::gotISOTPFrame(ISOTP_MESSAGE msg)
 {
     qDebug() << "UDS handler got ISOTP frame";
     UDS_MESSAGE udsMsg;
@@ -195,13 +195,13 @@ void UDS_HANDLER::setReception(bool mode)
 
     if (isReceiving)
     {
-        connect(ISOTP_HANDLER::getInstance(), SIGNAL(newISOMessage(ISOTP_MESSAGE&)), this, SLOT(gotISOTPFrame(ISOTP_MESSAGE&)));
+        connect(ISOTP_HANDLER::getInstance(), SIGNAL(newISOMessage(ISOTP_MESSAGE)), this, SLOT(gotISOTPFrame(ISOTP_MESSAGE)));
         ISOTP_HANDLER::getInstance()->setReception(true); //must enable ISOTP reception too.
         qDebug() << "Enabling reception of ISO-TP frames in UDS handler";
     }
     else
     {
-        disconnect(ISOTP_HANDLER::getInstance(), SIGNAL(newISOMessage(ISOTP_MESSAGE&)), this, SLOT(gotISOTPFrame(ISOTP_MESSAGE&)));
+        disconnect(ISOTP_HANDLER::getInstance(), SIGNAL(newISOMessage(ISOTP_MESSAGE)), this, SLOT(gotISOTPFrame(ISOTP_MESSAGE)));
         //can't disable ISOTP reception because something else might be using it.
         qDebug() << "Disabling reception of ISOTP frames in UDS handler";
     }
@@ -264,3 +264,25 @@ QString UDS_HANDLER::getNegativeResponseLong(int respCode)
     return QString();
 }
 
+//Little shim functions that drop straight through to the ISO_TP handler
+void UDS_HANDLER::setProcessAllIDs(bool state)
+{
+    ISOTP_HANDLER::getInstance()->setProcessAll(state);
+}
+
+void UDS_HANDLER::addID(uint32_t id)
+{
+    ISOTP_HANDLER::getInstance()->addID(id);
+}
+
+void UDS_HANDLER::removeID(uint32_t id)
+{
+    ISOTP_HANDLER::getInstance()->removeID(id);
+}
+
+void UDS_HANDLER::clearAllIDs()
+{
+    ISOTP_HANDLER::getInstance()->clearAllIDs();
+}
+
+
diff --git a/bus_protocols/uds_handler.h b/bus_protocols/uds_handler.h
index 8e745a3..e2133bb 100644
--- a/bus_protocols/uds_handler.h
+++ b/bus_protocols/uds_handler.h
@@ -89,16 +89,20 @@ public:
     static UDS_HANDLER* getInstance();
     void setReception(bool mode); //set whether to accept and forward frames or not
     void sendUDSFrame(const UDS_MESSAGE &msg);
+    void setProcessAllIDs(bool state);
+    void addID(uint32_t id);
+    void removeID(uint32_t id);
+    void clearAllIDs();
     QString getServiceShortDesc(int service);
     QString getServiceLongDesc(int service);
     QString getNegativeResponseShort(int respCode);
     QString getNegativeResponseLong(int respCode);
 
 public slots:
-    void gotISOTPFrame(ISOTP_MESSAGE &msg);
+    void gotISOTPFrame(ISOTP_MESSAGE msg);
 
 signals:
-    void newUDSMessage(UDS_MESSAGE &msg);
+    void newUDSMessage(UDS_MESSAGE msg);
 
 private:
     QList<ISOTP_MESSAGE> messageBuffer;
diff --git a/frameplaybackwindow.cpp b/frameplaybackwindow.cpp
index 10e8dd4..45db837 100644
--- a/frameplaybackwindow.cpp
+++ b/frameplaybackwindow.cpp
@@ -36,6 +36,7 @@ FramePlaybackWindow::FramePlaybackWindow(const QVector<CANFrame> *frames, QWidge
     modelFrames = frames;
 
     playbackTimer = new QTimer();
+    playbackTimer->setTimerType(Qt::PreciseTimer);
 
     currentPosition = 0;
     playbackActive = false;
@@ -499,7 +500,7 @@ void FramePlaybackWindow::btnSelectNoneClick()
 }
 
 void FramePlaybackWindow::timerTriggered()
-{    
+{
     sendingBuffer.clear();
     for (int count = 0; count < ui->spinBurstSpeed->value(); count++)
     {
diff --git a/framesenderwindow.cpp b/framesenderwindow.cpp
index e91d12b..1108e20 100644
--- a/framesenderwindow.cpp
+++ b/framesenderwindow.cpp
@@ -23,6 +23,7 @@ FrameSenderWindow::FrameSenderWindow(const QVector<CANFrame> *frames, QWidget *p
     modelFrames = frames;
 
     intervalTimer = new QTimer();
+    intervalTimer->setTimerType(Qt::PreciseTimer);
     intervalTimer->setInterval(1);
 
     QStringList headers;
@@ -45,7 +46,7 @@ FrameSenderWindow::FrameSenderWindow(const QVector<CANFrame> *frames, QWidget *p
     connect(ui->btnDisableAll, SIGNAL(clicked(bool)), this, SLOT(disableAll()));
     connect(ui->btnEnableAll, SIGNAL(clicked(bool)), this, SLOT(enableAll()));
     connect(ui->btnLoadGrid, SIGNAL(clicked(bool)), this, SLOT(loadGrid()));
-    connect(ui->btnSaveGrid, SIGNAL(clicked(bool)), this, SLOT(saveGrid()));    
+    connect(ui->btnSaveGrid, SIGNAL(clicked(bool)), this, SLOT(saveGrid()));
     connect(MainWindow::getReference(), SIGNAL(framesUpdated(int)), this, SLOT(updatedFrames(int)));
 
     intervalTimer->start();
@@ -56,7 +57,7 @@ FrameSenderWindow::~FrameSenderWindow()
 {
     delete ui;
 
-    intervalTimer->stop();    
+    intervalTimer->stop();
     delete intervalTimer;
 }
 
@@ -110,7 +111,7 @@ void FrameSenderWindow::updatedFrames(int numFrames)
         buildFrameCache();
     }
     else //just got some new frames. See if they are relevant.
-    {        
+    {
         if (numFrames > modelFrames->count()) return;
         qDebug() << "New frames in sender window";
         //run through the supposedly new frames in order
@@ -134,7 +135,7 @@ void FrameSenderWindow::processIncomingFrame(CANFrame *frame)
 {
     for (int sd = 0; sd < sendingData.count(); sd++)
     {
-        if (sendingData[sd].triggers.count() == 0) continue;        
+        if (sendingData[sd].triggers.count() == 0) continue;
         for (int trig = 0; trig < sendingData[sd].triggers.count(); trig++)
         {
             Trigger *thisTrigger = &sendingData[sd].triggers[trig];
diff --git a/re/isotp_interpreterwindow.cpp b/re/isotp_interpreterwindow.cpp
index 54ccd52..3a1bc45 100644
--- a/re/isotp_interpreterwindow.cpp
+++ b/re/isotp_interpreterwindow.cpp
@@ -11,6 +11,9 @@ ISOTP_InterpreterWindow::ISOTP_InterpreterWindow(const QVector<CANFrame> *frames
 
     decoder = ISOTP_HANDLER::getInstance();
 
+    decoder->setReception(true);
+    decoder->setProcessAll(true);
+
     connect(MainWindow::getReference(), &MainWindow::framesUpdated, this, &ISOTP_InterpreterWindow::updatedFrames);
     connect(MainWindow::getReference(), &MainWindow::framesUpdated, decoder, &ISOTP_HANDLER::updatedFrames);
     connect(decoder, &ISOTP_HANDLER::newISOMessage, this, &ISOTP_InterpreterWindow::newISOMessage);
@@ -123,7 +126,7 @@ void ISOTP_InterpreterWindow::showDetailView()
 
 }
 
-void ISOTP_InterpreterWindow::newISOMessage(ISOTP_MESSAGE &msg)
+void ISOTP_InterpreterWindow::newISOMessage(ISOTP_MESSAGE msg)
 {
     int rowNum;
     QString tempString;
diff --git a/re/isotp_interpreterwindow.h b/re/isotp_interpreterwindow.h
index 354cef0..5430ef2 100644
--- a/re/isotp_interpreterwindow.h
+++ b/re/isotp_interpreterwindow.h
@@ -21,7 +21,7 @@ public:
     void showEvent(QShowEvent*);
 
 private slots:
-    void newISOMessage(ISOTP_MESSAGE &msg);
+    void newISOMessage(ISOTP_MESSAGE msg);
     void showDetailView();
     void updatedFrames(int);
 
diff --git a/re/udsscanwindow.cpp b/re/udsscanwindow.cpp
index b2088b0..6c9100b 100644
--- a/re/udsscanwindow.cpp
+++ b/re/udsscanwindow.cpp
@@ -19,6 +19,7 @@ UDSScanWindow::UDSScanWindow(const QVector<CANFrame> *frames, QWidget *parent) :
     waitTimer->setInterval(100);
 
     UDS_HANDLER::getInstance()->setReception(true);
+    UDS_HANDLER::getInstance()->setProcessAllIDs(true);
 
     connect(MainWindow::getReference(), SIGNAL(framesUpdated(int)), this, SLOT(updatedFrames(int)));
     connect(UDS_HANDLER::getInstance(), &UDS_HANDLER::newUDSMessage, this, &UDSScanWindow::gotUDSReply);
@@ -317,7 +318,7 @@ void UDSScanWindow::updatedFrames(int numFrames)
     }
 }
 
-void UDSScanWindow::gotUDSReply(UDS_MESSAGE &msg)
+void UDSScanWindow::gotUDSReply(UDS_MESSAGE msg)
 {
     QString result;
     QString serviceShortName;
diff --git a/re/udsscanwindow.h b/re/udsscanwindow.h
index 33bea56..b89498f 100644
--- a/re/udsscanwindow.h
+++ b/re/udsscanwindow.h
@@ -23,7 +23,7 @@ public:
 
 private slots:
     void updatedFrames(int numFrames);
-    void gotUDSReply(UDS_MESSAGE &msg);
+    void gotUDSReply(UDS_MESSAGE msg);
     void scanUDS();
     void saveResults();
     void timeOut();