diff --git a/Software/PC_Application/Generator/generator.cpp b/Software/PC_Application/Generator/generator.cpp
index b3fc876..04dbc6f 100644
--- a/Software/PC_Application/Generator/generator.cpp
+++ b/Software/PC_Application/Generator/generator.cpp
@@ -55,12 +55,8 @@ void Generator::updateDevice()
 void Generator::setupSCPI()
 {
     add(new SCPICommand("FREQuency", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toUInt(&ok);
-        if(!ok) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             central->setFrequency(newval);
@@ -70,12 +66,9 @@ void Generator::setupSCPI()
         return QString::number(central->getDeviceStatus().frequency);
     }));
     add(new SCPICommand("LVL", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toDouble(&ok);
-        if(!ok) {
+        double newval;
+        if(!SCPI::paramToDouble(params, 0, newval)) {
+
             return "ERROR";
         } else {
             central->setLevel(newval);
@@ -85,12 +78,8 @@ void Generator::setupSCPI()
         return QString::number(central->getDeviceStatus().cdbm_level / 100.0);
     }));
     add(new SCPICommand("PORT", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toUInt(&ok);
-        if(!ok || newval > 2) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval) || newval > 2) {
             return "ERROR";
         } else {
             central->setPort(newval);
diff --git a/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp b/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp
index 2b4c4ec..310fd5c 100644
--- a/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp
+++ b/Software/PC_Application/SpectrumAnalyzer/spectrumanalyzer.cpp
@@ -658,21 +658,9 @@ void SpectrumAnalyzer::SetupSCPI()
 {
     auto scpi_freq = new SCPINode("FREQuency");
     SCPINode::add(scpi_freq);
-    auto toULong = [](QStringList params) {
-        bool ok;
-        if(params.size() != 1) {
-            return std::numeric_limits<unsigned long>::max();
-        }
-        auto newval = params[0].toULong(&ok);
-        if(!ok) {
-            return std::numeric_limits<unsigned long>::max();
-        } else {
-            return newval;
-        }
-    };
     scpi_freq->add(new SCPICommand("SPAN", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetSpan(newval);
@@ -682,8 +670,8 @@ void SpectrumAnalyzer::SetupSCPI()
         return QString::number(settings.f_stop - settings.f_start);
     }));
     scpi_freq->add(new SCPICommand("START", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetStartFreq(newval);
@@ -693,8 +681,8 @@ void SpectrumAnalyzer::SetupSCPI()
         return QString::number(settings.f_start);
     }));
     scpi_freq->add(new SCPICommand("CENTer", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetCenterFreq(newval);
@@ -704,8 +692,8 @@ void SpectrumAnalyzer::SetupSCPI()
         return QString::number((settings.f_start + settings.f_stop)/2);
     }));
     scpi_freq->add(new SCPICommand("STOP", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetStopFreq(newval);
@@ -722,8 +710,8 @@ void SpectrumAnalyzer::SetupSCPI()
     auto scpi_acq = new SCPINode("ACQuisition");
     SCPINode::add(scpi_acq);
     scpi_acq->add(new SCPICommand("RBW", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetRBW(newval);
@@ -786,8 +774,8 @@ void SpectrumAnalyzer::SetupSCPI()
         }
     }));
     scpi_acq->add(new SCPICommand("AVG", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetAveraging(newval);
@@ -844,12 +832,9 @@ void SpectrumAnalyzer::SetupSCPI()
         return settings.trackingGeneratorPort ? "2" : "1";
     }));
     scpi_tg->add(new SCPICommand("LVL", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toDouble(&ok);
-        if(!ok) {
+        double newval;
+        if(!SCPI::paramToDouble(params, 0, newval)) {
+
             return "ERROR";
         } else {
             SetTGLevel(newval);
@@ -859,12 +844,8 @@ void SpectrumAnalyzer::SetupSCPI()
         return QString::number(settings.trackingPower / 100.0);
     }));
     scpi_tg->add(new SCPICommand("OFFset", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toLong(&ok);
-        if(!ok) {
+        long newval;
+        if(!SCPI::paramToLong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetTGOffset(newval);
@@ -896,12 +877,8 @@ void SpectrumAnalyzer::SetupSCPI()
         return "";
     }, nullptr));
     scpi_norm->add(new SCPICommand("LVL", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toDouble(&ok);
-        if(!ok) {
+        double newval;
+        if(!SCPI::paramToDouble(params, 0, newval)) {
             return "ERROR";
         } else {
             SetNormalizationLevel(newval);
diff --git a/Software/PC_Application/Traces/trace.cpp b/Software/PC_Application/Traces/trace.cpp
index 928d8db..0f55b9d 100644
--- a/Software/PC_Application/Traces/trace.cpp
+++ b/Software/PC_Application/Traces/trace.cpp
@@ -78,6 +78,7 @@ void Trace::addData(const Trace::Data& d) {
                 *lower = d;
             }
             break;
+        default: break;
         }
     } else {
         // insert at this position
@@ -512,6 +513,94 @@ std::vector<Protocol::Datapoint> Trace::assembleDatapoints(const Trace &S11, con
     return ret;
 }
 
+Trace::LiveParameter Trace::ParameterFromString(QString s)
+{
+    s = s.toUpper();
+    if(s == "S11") {
+        return LiveParameter::S11;
+    } else if(s == "S12") {
+        return LiveParameter::S12;
+    } else if(s == "S21") {
+        return LiveParameter::S21;
+    } else if(s == "S22") {
+        return LiveParameter::S22;
+    } else if(s == "PORT1") {
+        return LiveParameter::Port1;
+    } else if(s == "PORT2") {
+        return LiveParameter::Port2;
+    } else {
+        return LiveParameter::Invalid;
+    }
+}
+
+QString Trace::ParameterToString(LiveParameter p)
+{
+    switch(p) {
+    case Trace::LiveParameter::S11: return "S11";
+    case Trace::LiveParameter::S12: return "S12";
+    case Trace::LiveParameter::S21: return "S21";
+    case Trace::LiveParameter::S22: return "S22";
+    case Trace::LiveParameter::Port1: return "Port1";
+    case Trace::LiveParameter::Port2: return "Port2";
+    default: return "Invalid";
+    }
+}
+
+bool Trace::isVNAParameter(Trace::LiveParameter p)
+{
+    switch(p) {
+    case Trace::LiveParameter::S11:
+    case Trace::LiveParameter::S12:
+    case Trace::LiveParameter::S21:
+    case Trace::LiveParameter::S22:
+        return true;
+    case Trace::LiveParameter::Port1:
+    case Trace::LiveParameter::Port2:
+    default:
+        return false;
+    }
+}
+
+bool Trace::isSAParamater(Trace::LiveParameter p)
+{
+    switch(p) {
+    case Trace::LiveParameter::S11:
+    case Trace::LiveParameter::S12:
+    case Trace::LiveParameter::S21:
+    case Trace::LiveParameter::S22:
+        return false;
+    case Trace::LiveParameter::Port1:
+    case Trace::LiveParameter::Port2:
+        return true;
+    default:
+        return false;
+    }
+}
+
+Trace::LivedataType Trace::TypeFromString(QString s)
+{
+    s = s.toUpper();
+    if(s == "OVERWRITE") {
+        return LivedataType::Overwrite;
+    } else if(s == "MAXHOLD") {
+        return LivedataType::MaxHold;
+    } else if(s == "MINHOLD") {
+        return LivedataType::MinHold;
+    } else {
+        return LivedataType::Invalid;
+    }
+}
+
+QString Trace::TypeToString(Trace::LivedataType t)
+{
+    switch(t) {
+    case Trace::LivedataType::Overwrite: return "Overwrite";
+    case Trace::LivedataType::MaxHold: return "MaxHold";
+    case Trace::LivedataType::MinHold: return "MinHold";
+    default: return "Invalid";
+    }
+}
+
 void Trace::updateLastMath(vector<MathInfo>::reverse_iterator start)
 {
     TraceMath *newLast = nullptr;
@@ -579,12 +668,18 @@ bool Trace::isVisible()
 
 void Trace::pause()
 {
-    paused = true;
+    if(!paused) {
+        paused = true;
+        emit pauseChanged();
+    }
 }
 
 void Trace::resume()
 {
-    paused = false;
+    if(paused) {
+        paused = false;
+        emit pauseChanged();
+    }
 }
 
 bool Trace::isPaused()
@@ -811,6 +906,12 @@ Trace::Data Trace::sample(unsigned int index, SampleType type) const
     return data;
 }
 
+Trace::Data Trace::interpolatedSample(double x)
+{
+    auto data = lastMath->getInterpolatedSample(x);
+    return data;
+}
+
 QString Trace::getFilename() const
 {
     return filename;
diff --git a/Software/PC_Application/Traces/trace.h b/Software/PC_Application/Traces/trace.h
index 2410682..8f51b31 100644
--- a/Software/PC_Application/Traces/trace.h
+++ b/Software/PC_Application/Traces/trace.h
@@ -27,6 +27,7 @@ public:
         S22,
         Port1,
         Port2,
+        Invalid,
     };
 
     Trace(QString name = QString(), QColor color = Qt::darkYellow, LiveParameter live = LiveParameter::S11);
@@ -36,6 +37,7 @@ public:
         Overwrite,
         MaxHold,
         MinHold,
+        Invalid,
     };
 
 
@@ -79,6 +81,8 @@ public:
     };
 
     Data sample(unsigned int index, SampleType type = SampleType::Frequency) const;
+    // returns a (possibly interpolated sample) at a specified frequency/time
+    Data interpolatedSample(double x);
     QString getFilename() const;
     unsigned int getFileParameter() const;
     /* Returns the noise in dbm/Hz for spectrum analyzer measurements. May return NaN if calculation not possible */
@@ -130,6 +134,14 @@ public:
     // have the same number of samples and their samples must be at the same frequencies across all traces
     static std::vector<Protocol::Datapoint> assembleDatapoints(const Trace &S11, const Trace &S12, const Trace &S21, const Trace &S22);
 
+    static LiveParameter ParameterFromString(QString s);
+    static QString ParameterToString(LiveParameter p);
+    static bool isVNAParameter(LiveParameter p);
+    static bool isSAParamater(LiveParameter p);
+
+    static LivedataType TypeFromString(QString s);
+    static QString TypeToString(LivedataType t);
+
 public slots:
     void setVisible(bool visible);
     void setColor(QColor color);
@@ -143,6 +155,7 @@ signals:
     void visibilityChanged(Trace *t);
     void dataChanged();
     void nameChanged();
+    void pauseChanged();
     void colorChanged(Trace *t);
     void markerAdded(TraceMarker *m);
     void markerRemoved(TraceMarker *m);
diff --git a/Software/PC_Application/Traces/traceeditdialog.cpp b/Software/PC_Application/Traces/traceeditdialog.cpp
index bfc697d..a535794 100644
--- a/Software/PC_Application/Traces/traceeditdialog.cpp
+++ b/Software/PC_Application/Traces/traceeditdialog.cpp
@@ -65,25 +65,18 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
     case Trace::LivedataType::Overwrite: ui->CLiveType->setCurrentIndex(0); break;
     case Trace::LivedataType::MaxHold: ui->CLiveType->setCurrentIndex(1); break;
     case Trace::LivedataType::MinHold: ui->CLiveType->setCurrentIndex(2); break;
+    default: break;
     }
 
-    switch(t.liveParameter()) {
-    case Trace::LiveParameter::S11:
-    case Trace::LiveParameter::S12:
-    case Trace::LiveParameter::S21:
-    case Trace::LiveParameter::S22:
-        VNAtrace = true;
+    VNAtrace = Trace::isVNAParameter(t.liveParameter());
+    if(VNAtrace) {
         ui->CLiveParam->addItem("S11");
         ui->CLiveParam->addItem("S12");
         ui->CLiveParam->addItem("S21");
         ui->CLiveParam->addItem("S22");
-        break;
-    case Trace::LiveParameter::Port1:
-    case Trace::LiveParameter::Port2:
+    } else {
         ui->CLiveParam->addItem("Port 1");
         ui->CLiveParam->addItem("Port 2");
-        VNAtrace = false;
-        break;
     }
 
     switch(t.liveParameter()) {
@@ -93,6 +86,7 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
     case Trace::LiveParameter::S22: ui->CLiveParam->setCurrentIndex(3); break;
     case Trace::LiveParameter::Port1: ui->CLiveParam->setCurrentIndex(0); break;
     case Trace::LiveParameter::Port2: ui->CLiveParam->setCurrentIndex(1); break;
+    default: break;
     }
 
     connect(ui->GSource, qOverload<int>(&QButtonGroup::buttonClicked), updateFileStatus);
diff --git a/Software/PC_Application/Traces/tracemarker.cpp b/Software/PC_Application/Traces/tracemarker.cpp
index 1453807..12e807b 100644
--- a/Software/PC_Application/Traces/tracemarker.cpp
+++ b/Software/PC_Application/Traces/tracemarker.cpp
@@ -396,6 +396,7 @@ std::set<TraceMarker::Type> TraceMarker::getSupportedTypes()
                     supported.insert(Type::TOI);
                     supported.insert(Type::PhaseNoise);
                     break;
+                default: break;
                 }
             }
         }
diff --git a/Software/PC_Application/Traces/tracemodel.cpp b/Software/PC_Application/Traces/tracemodel.cpp
index aa231ab..97ecfd4 100644
--- a/Software/PC_Application/Traces/tracemodel.cpp
+++ b/Software/PC_Application/Traces/tracemodel.cpp
@@ -22,7 +22,11 @@ void TraceModel::addTrace(Trace *t)
 {
     beginInsertRows(QModelIndex(), traces.size(), traces.size());
     connect(t, &Trace::nameChanged, [=]() {
-       emit traceNameChanged(t);
+        emit traceNameChanged(t);
+        emit dataChanged(createIndex(0, 0), createIndex(traces.size() - 1, ColIndexLast - 1));
+    });
+    connect(t, &Trace::pauseChanged, [=](){
+        emit dataChanged(createIndex(0, 0), createIndex(traces.size() - 1, ColIndexLast - 1));
     });
     traces.push_back(t);
     endInsertRows();
diff --git a/Software/PC_Application/Traces/tracewidget.cpp b/Software/PC_Application/Traces/tracewidget.cpp
index c065c82..3cd251b 100644
--- a/Software/PC_Application/Traces/tracewidget.cpp
+++ b/Software/PC_Application/Traces/tracewidget.cpp
@@ -185,4 +185,104 @@ void TraceWidget::SetupSCPI()
         ret.chop(1);
         return ret;
     }));
+    add(new SCPICommand("AT", nullptr, [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        double x;
+        if(!SCPI::paramToDouble(params, 1, x)) {
+            return "ERROR";
+        } else {
+            auto d = t->interpolatedSample(x);
+            if(std::isnan(d.x)) {
+                return "NaN,NaN";
+            } else {
+                return QString::number(d.y.real())+","+QString::number(d.y.imag());
+            }
+        }
+    }));
+    add(new SCPICommand("NEW", [=](QStringList params) -> QString {
+        if(params.size() != 1) {
+            return "ERROR";
+        }
+        createCount++;
+        auto t = new Trace(params[0], Qt::darkYellow, defaultParameter());
+        t->setColor(QColor::fromHsl((createCount * 50) % 360, 250, 128));
+        model.addTrace(t);
+        return "";
+    }, nullptr));
+    add(new SCPICommand("RENAME", [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        if(params.size() != 2) {
+            return "ERROR";
+        }
+        t->setName(params[1]);
+        return "";
+    }, nullptr));
+    add(new SCPICommand("PAUSE", [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        t->pause();
+        return "";
+    }, nullptr));
+    add(new SCPICommand("RESUME", [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        t->resume();
+        return "";
+    }, nullptr));
+    add(new SCPICommand("PAUSED", nullptr, [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        return t->isPaused() ? "TRUE" : "FALSE";
+    }));
+    add(new SCPICommand("PARAMeter", [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t || params.size() < 2) {
+           return "ERROR";
+        }
+        auto newparam = Trace::ParameterFromString(params[1]);
+        if((Trace::isVNAParameter(t->liveParameter()) && Trace::isVNAParameter(newparam))
+                || (Trace::isVNAParameter(t->liveParameter()) && Trace::isVNAParameter(newparam))) {
+            t->fromLivedata(t->liveType(), newparam);
+            return "";
+        } else {
+            return "ERROR";
+        }
+    }, [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        return Trace::ParameterToString(t->liveParameter());
+    }));
+    add(new SCPICommand("TYPE", [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t || params.size() < 2) {
+           return "ERROR";
+        }
+        auto newtype = Trace::TypeFromString(params[1]);
+        if(newtype != Trace::LivedataType::Invalid) {
+            t->fromLivedata(newtype, t->liveParameter());
+            return "";
+        } else {
+            return "ERROR";
+        }
+    }, [=](QStringList params) -> QString {
+        auto t = findTrace(params);
+        if(!t) {
+           return "ERROR";
+        }
+        return Trace::TypeToString(t->liveType());
+    }));
 }
diff --git a/Software/PC_Application/VNA/vna.cpp b/Software/PC_Application/VNA/vna.cpp
index 2badd02..e1a9341 100644
--- a/Software/PC_Application/VNA/vna.cpp
+++ b/Software/PC_Application/VNA/vna.cpp
@@ -883,21 +883,9 @@ void VNA::SetupSCPI()
 {
     auto scpi_freq = new SCPINode("FREQuency");
     SCPINode::add(scpi_freq);
-    auto toULong = [](QStringList params) {
-        bool ok;
-        if(params.size() != 1) {
-            return std::numeric_limits<unsigned long>::max();
-        }
-        auto newval = params[0].toULong(&ok);
-        if(!ok) {
-            return std::numeric_limits<unsigned long>::max();
-        } else {
-            return newval;
-        }
-    };
     scpi_freq->add(new SCPICommand("SPAN", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetSpan(newval);
@@ -907,8 +895,8 @@ void VNA::SetupSCPI()
         return QString::number(settings.f_stop - settings.f_start);
     }));
     scpi_freq->add(new SCPICommand("START", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetStartFreq(newval);
@@ -918,8 +906,8 @@ void VNA::SetupSCPI()
         return QString::number(settings.f_start);
     }));
     scpi_freq->add(new SCPICommand("CENTer", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetCenterFreq(newval);
@@ -929,8 +917,8 @@ void VNA::SetupSCPI()
         return QString::number((settings.f_start + settings.f_stop)/2);
     }));
     scpi_freq->add(new SCPICommand("STOP", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetStopFreq(newval);
@@ -947,8 +935,8 @@ void VNA::SetupSCPI()
     auto scpi_acq = new SCPINode("ACQuisition");
     SCPINode::add(scpi_acq);
     scpi_acq->add(new SCPICommand("IFBW", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetIFBandwidth(newval);
@@ -958,8 +946,8 @@ void VNA::SetupSCPI()
         return QString::number(settings.if_bandwidth);
     }));
     scpi_acq->add(new SCPICommand("POINTS", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetPoints(newval);
@@ -969,8 +957,8 @@ void VNA::SetupSCPI()
         return QString::number(settings.points);
     }));
     scpi_acq->add(new SCPICommand("AVG", [=](QStringList params) -> QString {
-        auto newval = toULong(params);
-        if(newval == std::numeric_limits<unsigned long>::max()) {
+        unsigned long newval;
+        if(!SCPI::paramToULong(params, 0, newval)) {
             return "ERROR";
         } else {
             SetAveraging(newval);
@@ -982,12 +970,8 @@ void VNA::SetupSCPI()
     auto scpi_stim = new SCPINode("STIMulus");
     SCPINode::add(scpi_stim);
     scpi_stim->add(new SCPICommand("LVL", [=](QStringList params) -> QString {
-        bool ok;
-        if(params.size() != 1) {
-            return "ERROR";
-        }
-        auto newval = params[0].toDouble(&ok);
-        if(!ok) {
+        double newval;
+        if(!SCPI::paramToDouble(params, 0, newval)) {
             return "ERROR";
         } else {
             SetSourceLevel(newval);
diff --git a/Software/PC_Application/scpi.cpp b/Software/PC_Application/scpi.cpp
index 552de78..592097e 100644
--- a/Software/PC_Application/scpi.cpp
+++ b/Software/PC_Application/scpi.cpp
@@ -32,6 +32,36 @@ QString SCPI::alternateName(QString name)
     return name;
 }
 
+bool SCPI::paramToDouble(QStringList params, int index, double &dest)
+{
+    if(index >= params.size()) {
+        return false;
+    }
+    bool okay;
+    dest = params[index].toDouble(&okay);
+    return okay;
+}
+
+bool SCPI::paramToULong(QStringList params, int index, unsigned long &dest)
+{
+    if(index >= params.size()) {
+        return false;
+    }
+    bool okay;
+    dest = params[index].toULong(&okay);
+    return okay;
+}
+
+bool SCPI::paramToLong(QStringList params, int index, long &dest)
+{
+    if(index >= params.size()) {
+        return false;
+    }
+    bool okay;
+    dest = params[index].toLong(&okay);
+    return okay;
+}
+
 void SCPI::input(QString line)
 {
     auto cmds = line.split(";");
diff --git a/Software/PC_Application/scpi.h b/Software/PC_Application/scpi.h
index a20baa9..3017a1b 100644
--- a/Software/PC_Application/scpi.h
+++ b/Software/PC_Application/scpi.h
@@ -51,6 +51,10 @@ public:
     static bool match(QString s1, QString s2);
     static QString alternateName(QString name);
 
+    static bool paramToDouble(QStringList params, int index, double &dest);
+    static bool paramToULong(QStringList params, int index, unsigned long &dest);
+    static bool paramToLong(QStringList params, int index, long &dest);
+
 public slots:
     void input(QString line);
 signals: