Experimental feature: only excite one port when other traces are paused

FPGA/VNA/Sweep.vhd

@@ -77,7 +77,7 @@ end Sweep;
 
 architecture Behavioral of Sweep is
 	signal point_cnt : unsigned(12 downto 0);
-	type Point_states is (TriggerSetup, SettingUp, SettlingPort1, ExcitingPort1, SettlingPort2, ExcitingPort2, Done);
+	type Point_states is (TriggerSetup, SettingUp, SettlingPort1, ExcitingPort1, SettlingPort2, ExcitingPort2, NextPoint, Done);
 	signal state : Point_states;
 	signal settling_cnt : unsigned(15 downto 0);
 	signal settling_time : unsigned(15 downto 0);
@@ -187,7 +187,7 @@ begin
 							if EXCITE_PORT2 = '1' then
 								state <= SettlingPort2;
 							else
-								state <= Done;
+								state <= NextPoint;
 							end if;
 							settling_cnt <= unsigned(SETTLING_TIME);
 						end if;
@@ -206,15 +206,18 @@ begin
 						-- wait for sampling to finish
 						START_SAMPLING <= '0';
 						if SAMPLING_BUSY = '0' then
+							state <= NextPoint;
+						end if;
+					when NextPoint =>
 						if point_cnt < unsigned(NPOINTS) then
 							point_cnt <= point_cnt + 1;
 							state <= TriggerSetup;
-								PORT_SELECT <= '1';
+							-- initial port depends on whether port 1 is exited
+							PORT_SELECT <= EXCITE_PORT1;
 						else 
 							point_cnt <= (others => '0');
 							state <= Done;
 						end if;					
-						end if;
 					when others =>
 				end case;
 			end if;

FPGA/VNA/VNA.gise

@@ -223,7 +223,7 @@
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1600104613" xil_pn:in_ck="-94812602667091528" xil_pn:name="TRANEXT_xstsynthesize_spartan6" xil_pn:prop_ck="3256065936432453276" xil_pn:start_ts="1600104595">
+    <transform xil_pn:end_ts="1600202513" xil_pn:in_ck="-94812602667091528" xil_pn:name="TRANEXT_xstsynthesize_spartan6" xil_pn:prop_ck="3256065936432453276" xil_pn:start_ts="1600202496">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="WarningsGenerated"/>
       <status xil_pn:value="ReadyToRun"/>
@@ -245,7 +245,7 @@
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1600116413" xil_pn:in_ck="490340488621696080" xil_pn:name="TRANEXT_ngdbuild_FPGA" xil_pn:prop_ck="4604875190571501774" xil_pn:start_ts="1600116406">
+    <transform xil_pn:end_ts="1600202519" xil_pn:in_ck="490340488621696080" xil_pn:name="TRANEXT_ngdbuild_FPGA" xil_pn:prop_ck="4604875190571501774" xil_pn:start_ts="1600202513">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_ngo"/>
@@ -254,12 +254,10 @@
       <outfile xil_pn:name="top.ngd"/>
       <outfile xil_pn:name="top_ngdbuild.xrpt"/>
     </transform>
-    <transform xil_pn:end_ts="1600116446" xil_pn:in_ck="8512332261572065657" xil_pn:name="TRANEXT_map_spartan6" xil_pn:prop_ck="1448924893915930207" xil_pn:start_ts="1600116413">
+    <transform xil_pn:end_ts="1600202564" xil_pn:in_ck="8512332261572065657" xil_pn:name="TRANEXT_map_spartan6" xil_pn:prop_ck="1448924893915930207" xil_pn:start_ts="1600202519">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="WarningsGenerated"/>
       <status xil_pn:value="ReadyToRun"/>
-      <status xil_pn:value="OutOfDateForOutputs"/>
-      <status xil_pn:value="OutputChanged"/>
       <outfile xil_pn:name="_xmsgs/map.xmsgs"/>
       <outfile xil_pn:name="top.pcf"/>
       <outfile xil_pn:name="top_map.map"/>
@@ -270,7 +268,7 @@
       <outfile xil_pn:name="top_summary.xml"/>
       <outfile xil_pn:name="top_usage.xml"/>
     </transform>
-    <transform xil_pn:end_ts="1600116473" xil_pn:in_ck="1117507038335044978" xil_pn:name="TRANEXT_par_spartan6" xil_pn:prop_ck="93661965788626211" xil_pn:start_ts="1600116446">
+    <transform xil_pn:end_ts="1600202589" xil_pn:in_ck="1117507038335044978" xil_pn:name="TRANEXT_par_spartan6" xil_pn:prop_ck="93661965788626211" xil_pn:start_ts="1600202564">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_xmsgs/par.xmsgs"/>
@@ -284,7 +282,7 @@
       <outfile xil_pn:name="top_pad.txt"/>
       <outfile xil_pn:name="top_par.xrpt"/>
     </transform>
-    <transform xil_pn:end_ts="1600116486" xil_pn:in_ck="154288912438" xil_pn:name="TRANEXT_bitFile_spartan6" xil_pn:prop_ck="3274353840855015246" xil_pn:start_ts="1600116473">
+    <transform xil_pn:end_ts="1600202602" xil_pn:in_ck="154288912438" xil_pn:name="TRANEXT_bitFile_spartan6" xil_pn:prop_ck="3274353840855015246" xil_pn:start_ts="1600202589">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="WarningsGenerated"/>
       <status xil_pn:value="ReadyToRun"/>
@@ -330,7 +328,7 @@
       <status xil_pn:value="OutputChanged"/>
       <status xil_pn:value="OutputRemoved"/>
     </transform>
-    <transform xil_pn:end_ts="1600116473" xil_pn:in_ck="8512326635937592693" xil_pn:name="TRAN_postRouteTrce" xil_pn:prop_ck="445577401284416184" xil_pn:start_ts="1600116466">
+    <transform xil_pn:end_ts="1600202589" xil_pn:in_ck="8512326635937592693" xil_pn:name="TRAN_postRouteTrce" xil_pn:prop_ck="445577401284416184" xil_pn:start_ts="1600202583">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_xmsgs/trce.xmsgs"/>

Software/PC_Application/Calibration/calibration.cpp

@@ -279,7 +279,12 @@ Calibration::InterpolationType Calibration::getInterpolation(Protocol::SweepSett
         return InterpolationType::Extrapolate;
     }
     // Either exact or interpolation, check individual frequencies
-    uint32_t f_step = (settings.f_stop - settings.f_start) / (settings.points - 1);
+    uint32_t f_step;
+    if(settings.points > 1) {
+        f_step = (settings.f_stop - settings.f_start) / (settings.points - 1);
+    } else {
+        f_step = settings.f_stop - settings.f_start;
+    }
     for(uint64_t f = settings.f_start; f <= settings.f_stop; f += f_step) {
         if(find_if(points.begin(), points.end(), [&f](const Point& p){
             return abs(f - p.frequency) < 100;
@@ -549,10 +554,10 @@ istream& operator >>(istream &in, Calibration &c)
                 } else {
                     throw runtime_error("Incomplete calibration data, the requested \"" + line + "\"-Calibration could not be performed.");
                 }
-            }
                 break;
             }
         }
+    }
     return in;
 }
 

Software/PC_Application/Traces/tracemodel.cpp

@@ -51,6 +51,7 @@ void TraceModel::togglePause(unsigned int index)
             traces[index]->pause();
         }
         emit dataChanged(createIndex(index, 1), createIndex(index, 1));
+        emit requiredExcitation(PortExcitationRequired(1), PortExcitationRequired(2));
     }
 }
 
@@ -109,6 +110,23 @@ std::vector<Trace *> TraceModel::getTraces()
     return traces;
 }
 
+bool TraceModel::PortExcitationRequired(int port)
+{
+    for(auto t : traces) {
+        if(t->isLive() && !t->isPaused()) {
+            // this trace needs measurements from VNA, check if port has to be excited for its measurement
+            auto param = t->liveParameter();
+            if(port == 1 && (param == Trace::LiveParameter::S11 || param == Trace::LiveParameter::S21)) {
+                return true;
+            } else if(port == 2 && (param == Trace::LiveParameter::S22 || param == Trace::LiveParameter::S12)) {
+                return true;
+            }
+        }
+    }
+    // checked all traces, none requires this port to be excited
+    return false;
+}
+
 void TraceModel::clearVNAData()
 {
     for(auto t : traces) {

Software/PC_Application/Traces/tracemodel.h

@@ -23,9 +23,12 @@ public:
     QVariant data(const QModelIndex &index, int role) const override;
 
     std::vector<Trace*> getTraces();
+
+    bool PortExcitationRequired(int port);
 signals:
     void traceAdded(Trace *t);
     void traceRemoved(Trace *t);
+    void requiredExcitation(bool excitePort1, bool excitePort2);
 
 public slots:
     void clearVNAData();

Software/PC_Application/VNA/vna.cpp

@@ -43,13 +43,9 @@
 
 VNA::VNA(AppWindow *window)
     : Mode(window, "Vector Network Analyzer"),
+      pref(window->getPreferenceRef()),
       central(new TileWidget(traceModel))
 {
-    QCoreApplication::setOrganizationName("VNA");
-    QCoreApplication::setApplicationName("Application");
-
-    pref.load();
-
     averages = 1;
     calValid = false;
     calMeasuring = false;
@@ -79,6 +75,8 @@ VNA::VNA(AppWindow *window)
     auto tracebode2 = new TraceBodePlot(traceModel);
     tracebode2->enableTrace(tS21, true);
 
+    connect(&traceModel, &TraceModel::requiredExcitation, this, &VNA::ExcitationRequired);
+
     central->splitVertically();
     central->Child1()->splitHorizontally();
     central->Child2()->splitHorizontally();
@@ -422,6 +420,13 @@ VNA::VNA(AppWindow *window)
     qRegisterMetaType<Protocol::Datapoint>("Datapoint");
 
     // Set initial sweep settings
+    if(pref.Acquisition.alwaysExciteBothPorts) {
+        settings.excitePort1 = 1;
+        settings.excitePort2 = 1;
+    } else {
+        settings.excitePort1 = traceModel.PortExcitationRequired(1);
+        settings.excitePort2 = traceModel.PortExcitationRequired(2);
+    }
     if(pref.Startup.RememberSweepSettings) {
         LoadSweepSettings();
     } else {
@@ -654,6 +659,22 @@ void VNA::SetAveraging(unsigned int averages)
     SettingsChanged();
 }
 
+void VNA::ExcitationRequired(bool port1, bool port2)
+{
+    qDebug() << pref.Acquisition.alwaysExciteBothPorts;
+    if(pref.Acquisition.alwaysExciteBothPorts) {
+        port1 = true;
+        port2 = true;
+    }
+    // check if settings actually changed
+    if(settings.excitePort1 != port1
+        || settings.excitePort2 != port2) {
+        settings.excitePort1 = port1;
+        settings.excitePort2 = port2;
+        SettingsChanged();
+    }
+}
+
 void VNA::DisableCalibration(bool force)
 {
     if(calValid || force) {

Software/PC_Application/VNA/vna.h

@@ -32,6 +32,7 @@ private slots:
     void SetPoints(unsigned int points);
     void SetIFBandwidth(double bandwidth);
     void SetAveraging(unsigned int averages);
+    void ExcitationRequired(bool port1, bool port2);
     // Calibration
     void DisableCalibration(bool force = false);
     void ApplyCalibration(Calibration::Type type);
@@ -47,9 +48,8 @@ private:
     void LoadSweepSettings();
     void StoreSweepSettings();
 
-    Preferences pref;
+    Preferences &pref;
 
-    QActionGroup *deviceActionGroup;
     Protocol::SweepSettings settings;
     unsigned int averages;
     TraceModel traceModel;

Software/PC_Application/appwindow.cpp

@@ -105,7 +105,9 @@ AppWindow::AppWindow(QWidget *parent)
         }
     });
     connect(ui->actionPreferences, &QAction::triggered, [=](){
+       qDebug() << pref.Acquisition.alwaysExciteBothPorts;
        pref.edit();
+       qDebug() << pref.Acquisition.alwaysExciteBothPorts;
     });
 
     setWindowTitle("VNA");
@@ -248,6 +250,11 @@ void AppWindow::CreateToolbars()
     addToolBar(tb_reference);
 }
 
+Preferences &AppWindow::getPreferenceRef()
+{
+    return pref;
+}
+
 int AppWindow::UpdateDeviceList()
 {
     deviceActionGroup->setExclusive(true);

Software/PC_Application/appwindow.h

@@ -34,6 +34,8 @@ public:
     QStackedWidget *getCentral() const;
     Device *getDevice() const;
 
+    Preferences &getPreferenceRef();
+
 protected:
     void closeEvent(QCloseEvent *event) override;
 private slots:

Software/PC_Application/preferences.cpp

@@ -66,6 +66,7 @@ PreferencesDialog::PreferencesDialog(Preferences *pref, QWidget *parent) :
         p->Startup.DefaultSweep.bandwidth = ui->StartupSweepBandwidth->value();
         p->Startup.DefaultSweep.points = ui->StartupSweepPoints->value();
         p->Startup.DefaultSweep.excitation = ui->StartupSweepLevel->value();
+        p->Acquisition.alwaysExciteBothPorts = ui->AcquisitionAlwaysExciteBoth->isChecked();
         accept();
     });
 
@@ -90,6 +91,8 @@ void PreferencesDialog::setInitialGUIState()
     ui->StartupSweepBandwidth->setValueQuiet(p->Startup.DefaultSweep.bandwidth);
     ui->StartupSweepPoints->setValue(p->Startup.DefaultSweep.points);
     ui->StartupSweepLevel->setValue(p->Startup.DefaultSweep.excitation);
+
+    ui->AcquisitionAlwaysExciteBoth->setChecked(p->Acquisition.alwaysExciteBothPorts);
 }
 
 void Preferences::load()

Software/PC_Application/preferences.h

@@ -46,13 +46,16 @@ public:
             double excitation;
         } DefaultSweep;
     } Startup;
+    struct {
+        bool alwaysExciteBothPorts;
+    } Acquisition;
 private:
     using SettingDescription = struct {
         QPointerVariant var;
         QString name;
         QVariant def;
     };
-    const std::array<SettingDescription, 7> descr = {{
+    const std::array<SettingDescription, 8> descr = {{
         {&Startup.ConnectToFirstDevice, "Startup.ConnectToFirstDevice", true},
         {&Startup.RememberSweepSettings, "Startup.RememberSweepSettings", false},
         {&Startup.DefaultSweep.start, "Startup.DefaultSweep.start", 1000000.0},
@@ -60,6 +63,7 @@ private:
         {&Startup.DefaultSweep.points, "Startup.DefaultSweep.points", 501},
         {&Startup.DefaultSweep.bandwidth, "Startup.DefaultSweep.bandwidth", 1000.0},
         {&Startup.DefaultSweep.excitation, "Startup.DefaultSweep.excitation", -10.00},
+        {&Acquisition.alwaysExciteBothPorts, "Acquisition.alwaysExciteBothPorts", false},
     }};
 };
 

Software/PC_Application/preferencesdialog.ui

@@ -232,7 +232,7 @@
        <widget class="QWidget" name="Acquisition">
         <layout class="QVBoxLayout" name="verticalLayout_5">
          <item>
-          <widget class="QCheckBox" name="checkBox">
+          <widget class="QCheckBox" name="AcquisitionAlwaysExciteBoth">
            <property name="toolTip">
             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;If only S11/S21 or S22/S12 are enabled, faster sweeps are possible by only exciting one port. Checking this option forces the device to always excite both ports even when the measurements from one port will not be used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
            </property>

Software/VNA_embedded/Application/App.cpp

@@ -178,8 +178,7 @@ void App_Start() {
 				case Protocol::PacketType::SweepSettings:
 					LOG_INFO("New settings received");
 					settings = packet.settings;
-					VNA::ConfigureSweep(settings, VNACallback);
+					sweepActive = VNA::ConfigureSweep(settings, VNACallback);
-					sweepActive = true;
 					lastNewPoint = HAL_GetTick();
 					Communication::SendWithoutPayload(Protocol::PacketType::Ack);
 					break;

Software/VNA_embedded/Application/Communication/Protocol.cpp

@@ -174,6 +174,8 @@ static Protocol::SweepSettings DecodeSweepSettings(uint8_t *buf) {
     e.get<uint16_t>(d.points);
     e.get<uint32_t>(d.if_bandwidth);
     e.get<int16_t>(d.cdbm_excitation);
+    d.excitePort1 = e.getBits(1);
+    d.excitePort2 = e.getBits(1);
     return d;
 }
 static int16_t EncodeSweepSettings(Protocol::SweepSettings d, uint8_t *buf,
@@ -184,6 +186,8 @@ static int16_t EncodeSweepSettings(Protocol::SweepSettings d, uint8_t *buf,
     e.add<uint16_t>(d.points);
     e.add<uint32_t>(d.if_bandwidth);
     e.add<int16_t>(d.cdbm_excitation);
+    e.addBits(d.excitePort1, 1);
+    e.addBits(d.excitePort2, 1);
     return e.getSize();
 }
 

Software/VNA_embedded/Application/Communication/Protocol.hpp

@@ -21,6 +21,8 @@ using SweepSettings = struct _sweepSettings {
     uint16_t points;
     uint32_t if_bandwidth;
     int16_t cdbm_excitation; // in 1/100 dbm
+	uint8_t excitePort1:1;
+	uint8_t excitePort2:1;
 };
 
 using ReferenceSettings = struct _referenceSettings {

Software/VNA_embedded/Application/VNA.cpp

@@ -82,9 +82,9 @@ static void ReadComplete(FPGA::SamplingResult result) {
 		auto ref = std::complex<float>(result.RefI, result.RefQ);
 		auto port1 = port1_raw / ref;
 		auto port2 = port2_raw / ref;
-		if(excitingPort1) {
 		data.pointNum = pointCnt;
 		data.frequency = settings.f_start + (settings.f_stop - settings.f_start) * pointCnt / (settings.points - 1);
+		if(excitingPort1) {
 			data.real_S11 = port1.real();
 			data.imag_S11 = port1.imag();
 			data.real_S21 = port2.real();
@@ -94,6 +94,19 @@ static void ReadComplete(FPGA::SamplingResult result) {
 			data.imag_S12 = port1.imag();
 			data.real_S22 = port2.real();
 			data.imag_S22 = port2.imag();
+		}
+		// figure out whether this sweep point is complete and which port gets excited next
+		bool pointComplete = false;
+		if(settings.excitePort1 == 1 && settings.excitePort2 == 1) {
+			// point is complete when port 2 was active
+			pointComplete = !excitingPort1;
+			// next measurement will be from other port
+			excitingPort1 = !excitingPort1;
+		} else {
+			// only one port active, point is complete after every measurement
+			pointComplete = true;
+		}
+		if(pointComplete) {
 			if (sweepCallback) {
 				sweepCallback(data);
 			}
@@ -102,10 +115,8 @@ static void ReadComplete(FPGA::SamplingResult result) {
 				// reached end of sweep, start again
 				pointCnt = 0;
 				IFTableIndexCnt = 0;
-	//			FPGA::StartSweep();
 			}
 		}
-		excitingPort1 = !excitingPort1;
 	} else {
 		// Manual control mode, simply pass on raw result
 		if(statusCallback) {
@@ -218,6 +229,11 @@ bool VNA::ConfigureSweep(Protocol::SweepSettings s, SweepCallback cb) {
 		// was used in manual mode last, do full initialization before starting sweep
 		VNA::Init();
 	}
+	if(s.excitePort1 == 0 && s.excitePort2 == 0) {
+		// both ports disabled, set to idle
+		SetIdle();
+		return false;
+	}
 	sweepCallback = cb;
 	settings = s;
 	// Abort possible active sweep first
@@ -316,7 +332,7 @@ bool VNA::ConfigureSweep(Protocol::SweepSettings s, SweepCallback cb) {
 		}
 		LO1.SetFrequency(freq + used_IF);
 		FPGA::WriteSweepConfig(i, lowband, Source.GetRegisters(),
-				LO1.GetRegisters(), attenuator, freq, FPGA::SettlingTime::us540,
+				LO1.GetRegisters(), attenuator, freq, FPGA::SettlingTime::us20,
 				FPGA::Samples::SPPRegister, needs_halt);
 		last_lowband = lowband;
 	}
@@ -332,10 +348,11 @@ bool VNA::ConfigureSweep(Protocol::SweepSettings s, SweepCallback cb) {
 	FPGA::Enable(FPGA::Periphery::SourceRF);
 	FPGA::Enable(FPGA::Periphery::LO1Chip);
 	FPGA::Enable(FPGA::Periphery::LO1RF);
-	FPGA::Enable(FPGA::Periphery::ExcitePort1);
+	FPGA::Enable(FPGA::Periphery::ExcitePort1, s.excitePort1);
-	FPGA::Enable(FPGA::Periphery::ExcitePort2);
+	FPGA::Enable(FPGA::Periphery::ExcitePort2, s.excitePort2);
 	pointCnt = 0;
-	excitingPort1 = true;
+	// starting port depends on whether port 1 is active in sweep
+	excitingPort1 = s.excitePort1;
 	IFTableIndexCnt = 0;
 	// Start the sweep
 	FPGA::StartSweep();
@@ -461,7 +478,10 @@ bool VNA::Ref::applySettings(Protocol::ReferenceSettings s) {
 			LOG_INFO("External reference output set to %luHz", extOutFreq);
 		}
 	}
-	bool useExternal = s.UseExternalRef || (s.AutomaticSwitch && Ref::available());
+	bool useExternal = s.UseExternalRef;
+	if (s.AutomaticSwitch) {
+		useExternal = Ref::available();
+	}
 	if(useExternal != extRefInUse) {
 		// switch between internal and external reference
 		extRefInUse = useExternal;

Software/VNA_embedded/Application/VNA.hpp

@@ -10,6 +10,7 @@ using SweepCallback = void(*)(Protocol::Datapoint);
 using StatusCallback = void(*)(FPGA::SamplingResult);
 
 bool Init();
+// returns whether the sweep is actually started
 bool ConfigureSweep(Protocol::SweepSettings s, SweepCallback cb);
 bool ConfigureManual(Protocol::ManualControl m, StatusCallback cb);
 bool ConfigureGenerator(Protocol::GeneratorSettings g);