Owon xdm driver fixes

scopehal/OwonXDMMultimeter.cpp

@@ -55,6 +55,9 @@ OwonXDMMultimeter::OwonXDMMultimeter(SCPITransport* transport)
 
 	// Set speed to high
 	m_transport->SendCommandQueued("RATE F");
+
+	// Rate limit to 65 Hz (which is the highest measurement supported by the metter)
+	m_transport->EnableRateLimiting(chrono::milliseconds(1000/65));
 }
 
 OwonXDMMultimeter::~OwonXDMMultimeter()
@@ -115,10 +118,10 @@ bool OwonXDMMultimeter::GetMeterAutoRange()
 void OwonXDMMultimeter::SetMeterAutoRange(bool enable)
 {
 	if(enable)
-		m_transport->SendCommandQueued("AUTO");
+		m_transport->SendCommandImmediate("AUTO");
 	else
 	{
-		m_transport->SendCommandQueued("RANGE 1");
+		m_transport->SendCommandImmediate("RANGE 1");
 	}
 }
 
@@ -143,6 +146,9 @@ double OwonXDMMultimeter::GetMeterValue()
 			LogWarning("Failed to read value: got '%s'\n",value.c_str());
 			continue;
 		}
+		else if(value == "1E+9") // Overload
+			return std::numeric_limits<double>::max();
+
 		istringstream os(value);
     	double result;
     	os >> result;
@@ -165,7 +171,9 @@ double OwonXDMMultimeter::GetSecondaryMeterValue()
 			// No secondary reading at this point
 			return 0;
 		}
-		if(value.empty()||(value.find("NON")!=std::string::npos))
+		else if(value == "1E+9")
+			return std::numeric_limits<double>::max(); // Overload
+		if(value.empty())
 		{
 			LogWarning("Failed to read value: got '%s'\n",value.c_str());
 			continue;
@@ -259,43 +267,43 @@ void OwonXDMMultimeter::SetMeterMode(Multimeter::MeasurementTypes type)
 	switch(type)
 	{
 		case DC_VOLTAGE:
-			m_transport->SendCommandQueued("CONF:VOLT:DC");
+			m_transport->SendCommandImmediate("CONF:VOLT:DC");
 			break;
 
 		case AC_RMS_AMPLITUDE:
-			m_transport->SendCommandQueued("CONF:VOLT:AC");
+			m_transport->SendCommandImmediate("CONF:VOLT:AC");
 			break;
 
 		case DC_CURRENT:
-			m_transport->SendCommandQueued("CONF:CURR:DC");
+			m_transport->SendCommandImmediate("CONF:CURR:DC");
 			break;
 
 		case AC_CURRENT:
-			m_transport->SendCommandQueued("CONF:CURR:AC");
+			m_transport->SendCommandImmediate("CONF:CURR:AC");
 			break;
 
 		case RESISTANCE:
-			m_transport->SendCommandQueued("CONF:RES");
+			m_transport->SendCommandImmediate("CONF:RES");
 			break;
 
 		case CAPACITANCE:
-			m_transport->SendCommandQueued("CONF:CAP");
+			m_transport->SendCommandImmediate("CONF:CAP");
 			break;
 
 		case FREQUENCY:
-			m_transport->SendCommandQueued("CONF:FREQ");
+			m_transport->SendCommandImmediate("CONF:FREQ");
 			break;
 
 		case DIODE:
-			m_transport->SendCommandQueued("CONF:DIOD");
+			m_transport->SendCommandImmediate("CONF:DIOD");
 			break;
 
 		case CONTINUITY:
-			m_transport->SendCommandQueued("CONF:CONT");
+			m_transport->SendCommandImmediate("CONF:CONT");
 			break;
 
 		case TEMPERATURE:
-			m_transport->SendCommandQueued("CONF:TEMP");
+			m_transport->SendCommandImmediate("CONF:TEMP");
 			break;
 
 		//whatever it is, not supported
@@ -313,11 +321,11 @@ void OwonXDMMultimeter::SetSecondaryMeterMode(Multimeter::MeasurementTypes type)
 	switch(type)
 	{
 		case FREQUENCY:
-			m_transport->SendCommandQueued("FUNC2 \"FREQ\"");
+			m_transport->SendCommandImmediate("FUNC2 \"FREQ\"");
 			break;
 
 		case NONE:
-			m_transport->SendCommandQueued("FUNC2 \"NONe\"");
+			m_transport->SendCommandImmediate("FUNC2 \"NONe\"");
 			break;
 
 		//not supported

scopehal/Unit.cpp

@@ -602,6 +602,10 @@ void Unit::GetUnitSuffix(UnitType type, double num, double& scaleFactor, string&
  */
 string Unit::PrettyPrint(double value, int sigfigs, bool useDisplayLocale) const
 {
+	// Special handling for overload value
+	if(value >= std::numeric_limits<double>::max())
+		return UNIT_OVERLOAD_LABEL;
+
 	if(useDisplayLocale)
 		SetPrintingLocale();
 
@@ -981,6 +985,10 @@ string Unit::PrettyPrintRange(double pixelMin, double pixelMax, double rangeMin,
  */
 double Unit::ParseString(const string& str, bool useDisplayLocale)
 {
+	// Special handling for overload value
+	if(str == UNIT_OVERLOAD_LABEL)
+		return std::numeric_limits<double>::max();
+
 	if(useDisplayLocale)
 		SetPrintingLocale();
 

scopehal/Unit.h

@@ -46,6 +46,8 @@
 
 #endif
 
+#define UNIT_OVERLOAD_LABEL "Overload"
+
 /**
 	@brief A unit of measurement, plus conversion to pretty-printed output