diff --git a/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp b/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp
index 775d312..a341fc6 100644
--- a/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp
+++ b/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp
@@ -298,6 +298,7 @@ nlohmann::json SpectrumAnalyzer::toJSON()
     nlohmann::json j;
     j["traces"] = traceModel.toJSON();
     j["tiles"] = central->toJSON();
+    j["markers"] = markerModel->toJSON();
     return j;
 }
 
@@ -309,6 +310,9 @@ void SpectrumAnalyzer::fromJSON(nlohmann::json j)
     if(j.contains("tiles")) {
         central->fromJSON(j["tiles"]);
     }
+    if(j.contains("markers")) {
+        markerModel->fromJSON(j["markers"]);
+    }
 }
 
 using namespace std;
diff --git a/Software/PC_Application/Traces/markerwidget.cpp b/Software/PC_Application/Traces/markerwidget.cpp
index a9957d9..8bb2d11 100644
--- a/Software/PC_Application/Traces/markerwidget.cpp
+++ b/Software/PC_Application/Traces/markerwidget.cpp
@@ -19,6 +19,13 @@ MarkerWidget::MarkerWidget(TraceMarkerModel &model, QWidget *parent) :
     connect(&model.getModel(), &TraceModel::traceAdded, this, &MarkerWidget::updatePersistentEditors);
     connect(&model.getModel(), &TraceModel::traceRemoved, this, &MarkerWidget::updatePersistentEditors);
     connect(&model.getModel(), &TraceModel::traceNameChanged, this, &MarkerWidget::updatePersistentEditors);
+    connect(&model, &TraceMarkerModel::markerAdded, [=](TraceMarker *m) {
+        connect(m, &TraceMarker::typeChanged, this, &MarkerWidget::updatePersistentEditors);
+        connect(m, &TraceMarker::traceChanged, this, &MarkerWidget::updatePersistentEditors);
+        connect(m, &TraceMarker::assignedDeltaChanged, this, &MarkerWidget::updatePersistentEditors);
+        updatePersistentEditors();
+    });
+    connect(&model, &TraceMarkerModel::setupLoadComplete, this, &MarkerWidget::updatePersistentEditors);
 }
 
 MarkerWidget::~MarkerWidget()
@@ -46,18 +53,13 @@ void MarkerWidget::on_bDelete_clicked()
         // can't delete child markers directly
         return;
     }
-    model.removeMarker(marker);
-    marker->blockSignals(true);
     delete marker;
 }
 
 void MarkerWidget::on_bAdd_clicked()
 {
     auto marker = model.createDefaultMarker();
-    connect(marker, &TraceMarker::typeChanged, this, &MarkerWidget::updatePersistentEditors);
-    connect(marker, &TraceMarker::traceChanged, this, &MarkerWidget::updatePersistentEditors);
     model.addMarker(marker);
-    updatePersistentEditors();
 }
 
 void MarkerWidget::updatePersistentEditors()
diff --git a/Software/PC_Application/Traces/tracemarker.cpp b/Software/PC_Application/Traces/tracemarker.cpp
index 30f46ac..dc2eed6 100644
--- a/Software/PC_Application/Traces/tracemarker.cpp
+++ b/Software/PC_Application/Traces/tracemarker.cpp
@@ -127,7 +127,7 @@ QString TraceMarker::readableData()
                 return QString::number(toDecibel(), 'g', 4) + "db@" + QString::number(phase*180/M_PI, 'g', 4);
             }
         case Type::Delta:
-            if(!delta && delta->isTimeDomain()) {
+            if(!delta || delta->isTimeDomain()) {
                 return "Invalid delta marker";
             } else {
                 // calculate difference between markers
@@ -288,10 +288,21 @@ void TraceMarker::parentTraceDeleted(Trace *t)
 
 void TraceMarker::traceDataChanged()
 {
-    // some data of the parent trace changed, check if marker data also changed
     complex<double> newdata;
-    auto sampleType = isTimeDomain() ? Trace::SampleType::TimeImpulse : Trace::SampleType::Frequency;
-    newdata = parentTrace->sample(parentTrace->index(position), sampleType).y;
+    if(!parentTrace || parentTrace->numSamples() == 0) {
+        // no data, invalidate
+        newdata = numeric_limits<complex<double>>::quiet_NaN();
+    } else {
+        if(position < parentTrace->minX() || position > parentTrace->maxX()) {
+            // this normally should not happen because the position is constrained to the trace X range.
+            // However, when loading a setup, the trace might have been just created and essentially empty
+            newdata = numeric_limits<complex<double>>::quiet_NaN();
+        } else {
+            // some data of the parent trace changed, check if marker data also changed
+            auto sampleType = isTimeDomain() ? Trace::SampleType::TimeImpulse : Trace::SampleType::Frequency;
+            newdata = parentTrace->sample(parentTrace->index(position), sampleType).y;
+        }
+    }
     if (newdata != data) {
         data = newdata;
         update();
@@ -328,7 +339,7 @@ void TraceMarker::checkDeltaMarker()
         return;
     }
     // Check if type of delta marker is still okay
-    if(delta->isTimeDomain() != isTimeDomain()) {
+    if(!delta || delta->isTimeDomain() != isTimeDomain()) {
         // not the same domain anymore, adjust delta
         assignDeltaMarker(bestDeltaCandidate());
     }
@@ -418,6 +429,10 @@ TraceMarker *TraceMarker::bestDeltaCandidate()
 
 void TraceMarker::assignDeltaMarker(TraceMarker *m)
 {
+    if(type != Type::Delta) {
+        // ignore
+        return;
+    }
     if(delta) {
         disconnect(delta, &TraceMarker::dataChanged, this, &TraceMarker::update);
     }
@@ -427,10 +442,13 @@ void TraceMarker::assignDeltaMarker(TraceMarker *m)
         connect(delta, &TraceMarker::rawDataChanged, this, &TraceMarker::update);
         connect(delta, &TraceMarker::domainChanged, this, &TraceMarker::checkDeltaMarker);
         connect(delta, &TraceMarker::deleted, [=](){
+            delta = nullptr;
+            qDebug() << "assigned delta deleted";
             assignDeltaMarker(bestDeltaCandidate());
             update();
         });
     }
+    emit assignedDeltaChanged(this);
 }
 
 void TraceMarker::deleteHelperMarkers()
@@ -507,11 +525,104 @@ bool TraceMarker::isVisible()
     }
 }
 
+TraceMarker::Type TraceMarker::getType() const
+{
+    return type;
+}
+
 QString TraceMarker::getSuffix() const
 {
     return suffix;
 }
 
+nlohmann::json TraceMarker::toJSON()
+{
+    nlohmann::json j;
+    j["trace"] = parentTrace->toHash();
+    j["type"] = typeToString(type).toStdString();
+    j["number"] = number;
+    j["position"] = position;
+    switch(type) {
+    case Type::Delta:
+        j["delta_marker"] = delta->toHash();
+        break;
+    case Type::PeakTable:
+        j["peak_threshold"] = peakThreshold;
+        break;
+    case Type::Lowpass:
+    case Type::Highpass:
+    case Type::Bandpass:
+        j["cutoff"] = cutoffAmplitude;
+        break;
+    case Type::PhaseNoise:
+        j["offset"] = offset;
+        break;
+    default:
+        // other types have no settings
+        break;
+    }
+    return j;
+}
+
+void TraceMarker::fromJSON(nlohmann::json j)
+{
+    if(!j.contains("trace")) {
+        throw runtime_error("Marker has no trace assigned");
+    }
+    number = j.value("number", 1);
+    position = j.value("position", 0.0);
+
+    unsigned int hash = j["trace"];
+    // find correct trace
+    bool found = false;
+    for(auto t : model->getModel().getTraces()) {
+        if(t->toHash() == hash) {
+            found = true;
+            assignTrace(t);
+            break;
+        }
+    }
+    if(!found) {
+        throw runtime_error("Unable to find trace with hash " + to_string(hash));
+    }
+    auto typeString = QString::fromStdString(j.value("type", "Manual"));
+    for(unsigned int i=0;i<(int) Type::Last;i++) {
+        if(typeToString((Type) i) == typeString) {
+            setType((Type) i);
+            break;
+        }
+    }
+    switch(type) {
+    case Type::Delta:
+        // can't assign delta marker here, because it might not have been created (if it was below this marker in the table).
+        // Instead it will be correctly assigned in TraceMarkerModel::fromJSON()
+        break;
+    case Type::PeakTable:
+        peakThreshold = j.value("peak_threshold", -40);
+        break;
+    case Type::Lowpass:
+    case Type::Highpass:
+    case Type::Bandpass:
+        cutoffAmplitude = j.value("cutoff", -3.0);
+        break;
+    case Type::PhaseNoise:
+        j.value("offset", 10000);
+        break;
+    default:
+        // other types have no settings
+        break;
+    }
+    update();
+}
+
+unsigned int TraceMarker::toHash()
+{
+    // taking the easy way: create the json string and hash it (already contains all necessary information)
+    // This is slower than it could be, but this function is only used when loading setups, so this isn't a big problem
+    std::string json_string = toJSON().dump();
+    return hash<std::string>{}(json_string);
+}
+
 const std::vector<TraceMarker *> &TraceMarker::getHelperMarkers() const
 {
     return helperMarkers;
diff --git a/Software/PC_Application/Traces/tracemarker.h b/Software/PC_Application/Traces/tracemarker.h
index a212339..3ec7f23 100644
--- a/Software/PC_Application/Traces/tracemarker.h
+++ b/Software/PC_Application/Traces/tracemarker.h
@@ -6,10 +6,11 @@
 #include "trace.h"
 #include <QComboBox>
 #include "CustomWidgets/siunitedit.h"
+#include "savable.h"
 
 class TraceMarkerModel;
 
-class TraceMarker : public QObject
+class TraceMarker : public QObject, public Savable
 {
     Q_OBJECT;
 public:
@@ -35,7 +36,22 @@ public:
     bool editingFrequeny;
     Trace *getTrace() const;
 
-
+    enum class Type {
+        Manual,
+        Maximum,
+        Minimum,
+        Delta,
+        Noise,
+        PeakTable,
+        Lowpass,
+        Highpass,
+        Bandpass,
+        TOI,
+        PhaseNoise,
+        // keep last at end
+        Last,
+    };
+    Type getType() const;
     QWidget *getTypeEditor(QAbstractItemDelegate *delegate = nullptr);
     void updateTypeFromEditor(QWidget *c);
     SIUnitEdit* getSettingsEditor();
@@ -46,8 +62,19 @@ public:
     TraceMarker *getParent() const;
     const std::vector<TraceMarker *>& getHelperMarkers() const;
     TraceMarker *helperMarker(unsigned int i);
+    void assignDeltaMarker(TraceMarker *m);
     QString getSuffix() const;
 
+    virtual nlohmann::json toJSON() override;
+    virtual void fromJSON(nlohmann::json j) override;
+    // Markers are referenced by pointers throughout this project (e.g. when added to a trace)
+    // When saving the current marker configuration, the pointer is not useful (e.g. for determining
+    // the associated delta marker. Instead a marker hash is saved to identify the correct marker.
+    // The hash should be influenced by every setting the marker can have. It should not depend on
+    // the marker data.
+    unsigned int toHash();
+
+
 public slots:
     void setPosition(double freq);
 signals:
@@ -55,6 +82,7 @@ signals:
     void dataChanged(TraceMarker *m);
     void symbolChanged(TraceMarker *m);
     void typeChanged(TraceMarker *m);
+    void assignedDeltaChanged(TraceMarker *m);
     void traceChanged(TraceMarker *m);
     void beginRemoveHelperMarkers(TraceMarker *m);
     void endRemoveHelperMarkers(TraceMarker *m);
@@ -68,20 +96,6 @@ signals:
     void rawDataChanged();
     void domainChanged();
 private:
-
-    enum class Type {
-        Manual,
-        Maximum,
-        Minimum,
-        Delta,
-        Noise,
-        PeakTable,
-        Lowpass,
-        Highpass,
-        Bandpass,
-        TOI,
-        PhaseNoise,
-    };
     std::set<Type> getSupportedTypes();
     static QString typeToString(Type t) {
         switch(t) {
@@ -101,7 +115,6 @@ private:
     }
     void constrainPosition();
     TraceMarker *bestDeltaCandidate();
-    void assignDeltaMarker(TraceMarker *m);
     void deleteHelperMarkers();
     void setType(Type t);
     double toDecibel();
diff --git a/Software/PC_Application/Traces/tracemarkermodel.cpp b/Software/PC_Application/Traces/tracemarkermodel.cpp
index f4d274c..45a7779 100644
--- a/Software/PC_Application/Traces/tracemarkermodel.cpp
+++ b/Software/PC_Application/Traces/tracemarkermodel.cpp
@@ -5,6 +5,8 @@
 #include "CustomWidgets/siunitedit.h"
 #include <QDebug>
 
+using namespace std;
+
 static constexpr int rowHeight = 21;
 
 TraceMarkerModel::TraceMarkerModel(TraceModel &model, QObject *parent)
@@ -268,6 +270,57 @@ TraceMarker *TraceMarkerModel::markerFromIndex(const QModelIndex &index) const
     }
 }
 
+nlohmann::json TraceMarkerModel::toJSON()
+{
+    nlohmann::json j;
+    for(auto m : markers) {
+        j.push_back(m->toJSON());
+    }
+    return j;
+}
+
+void TraceMarkerModel::fromJSON(nlohmann::json j)
+{
+    // remove old markers
+    while(markers.size() > 0) {
+        removeMarker((unsigned int) 0);
+    }
+    for(auto jm : j) {
+        auto m = new TraceMarker(this);
+        try {
+            m->fromJSON(jm);
+            addMarker(m);
+        } catch (const exception &e) {
+            qWarning() << "Failed to creat marker from JSON:" << e.what();
+            delete m;
+        }
+    }
+    // second pass to assign delta markers
+    for(unsigned int i=0;i<markers.size();i++) {
+        if(markers[i]->getType() == TraceMarker::Type::Delta) {
+            if(!j[i].contains("delta_marker")) {
+                qWarning() << "JSON data does not contain assigned delta marker";
+                continue;
+            }
+            unsigned int hash = j[i]["delta_marker"];
+            // attempt to find correct marker
+            unsigned int m_delta = 0;
+            for(;m_delta < markers.size();m_delta++) {
+                auto m = markers[m_delta];
+                if(m->toHash() == hash) {
+                    markers[i]->assignDeltaMarker(m);
+                    break;
+                }
+            }
+            if(m_delta >= markers.size()) {
+                qWarning() << "Unable to find assigned delta marker:" << hash;
+            }
+        }
+    }
+    // All done loading the markers, trigger update of persistent editors
+    emit setupLoadComplete();
+}
+
 QSize MarkerTraceDelegate::sizeHint(const QStyleOptionViewItem &, const QModelIndex &) const
 {
     return QSize(0, rowHeight);
diff --git a/Software/PC_Application/Traces/tracemarkermodel.h b/Software/PC_Application/Traces/tracemarkermodel.h
index 43582dc..13937d2 100644
--- a/Software/PC_Application/Traces/tracemarkermodel.h
+++ b/Software/PC_Application/Traces/tracemarkermodel.h
@@ -6,6 +6,7 @@
 #include <vector>
 #include "tracemodel.h"
 #include <QStyledItemDelegate>
+#include "savable.h"
 
 class MarkerTraceDelegate : public QStyledItemDelegate
 {
@@ -43,7 +44,7 @@ class MarkerSettingsDelegate : public QStyledItemDelegate
     void setModelData(QWidget * editor, QAbstractItemModel * model, const QModelIndex & index) const override;
 };
 
-class TraceMarkerModel : public QAbstractItemModel
+class TraceMarkerModel : public QAbstractItemModel, public Savable
 {
     Q_OBJECT
 public:
@@ -76,6 +77,9 @@ public:
     void updateMarkers();
     TraceMarker *markerFromIndex(const QModelIndex &index) const;
 
+    virtual nlohmann::json toJSON() override;
+    virtual void fromJSON(nlohmann::json j) override;
+
 public slots:
     void addMarker(TraceMarker *t);
     void removeMarker(unsigned int index);
@@ -84,6 +88,7 @@ public slots:
 
 signals:
     void markerAdded(TraceMarker *t);
+    void setupLoadComplete();
 
 private slots:
     void markerDataChanged(TraceMarker *m);
diff --git a/Software/PC_Application/Traces/tracesmithchart.cpp b/Software/PC_Application/Traces/tracesmithchart.cpp
index 7e04091..53e9fce 100644
--- a/Software/PC_Application/Traces/tracesmithchart.cpp
+++ b/Software/PC_Application/Traces/tracesmithchart.cpp
@@ -194,6 +194,10 @@ void TraceSmithChart::draw(QPainter &p) {
                 if (limitToSpan && (m->getPosition() < sweep_fmin || m->getPosition() > sweep_fmax)) {
                     continue;
                 }
+                if(m->getPosition() < trace->minX() || m->getPosition() > trace->maxX()) {
+                    // marker not in trace range
+                    continue;
+                }
                 auto coords = m->getData();
                 coords *= smithCoordMax;
                 auto symbol = m->getSymbol();
diff --git a/Software/PC_Application/Traces/tracexyplot.cpp b/Software/PC_Application/Traces/tracexyplot.cpp
index a3d92d3..279d61f 100644
--- a/Software/PC_Application/Traces/tracexyplot.cpp
+++ b/Software/PC_Application/Traces/tracexyplot.cpp
@@ -465,6 +465,11 @@ void TraceXYPlot::draw(QPainter &p)
                         xPosition = m->getPosition();
 //                    }
                     if (xPosition < XAxis.rangeMin || xPosition > XAxis.rangeMax) {
+                        // marker not in graph range
+                        continue;
+                    }
+                    if(xPosition < t->minX() || xPosition > t->maxX()) {
+                        // marker not in trace range
                         continue;
                     }
                     auto t = m->getTrace();
diff --git a/Software/PC_Application/VNA/vna.cpp b/Software/PC_Application/VNA/vna.cpp
index efeceb7..1ecd786 100644
--- a/Software/PC_Application/VNA/vna.cpp
+++ b/Software/PC_Application/VNA/vna.cpp
@@ -448,6 +448,7 @@ nlohmann::json VNA::toJSON()
     nlohmann::json j;
     j["traces"] = traceModel.toJSON();
     j["tiles"] = central->toJSON();
+    j["markers"] = markerModel->toJSON();
     return j;
 }
 
@@ -459,6 +460,9 @@ void VNA::fromJSON(nlohmann::json j)
     if(j.contains("tiles")) {
         central->fromJSON(j["tiles"]);
     }
+    if(j.contains("markers")) {
+        markerModel->fromJSON(j["markers"]);
+    }
 }
 
 using namespace std;