add total power factor

exporter/exporter.go

@@ -11,6 +11,7 @@ type Exporter struct {
 	ApparantPower    *prometheus.GaugeVec
 	ActivePower      *prometheus.GaugeVec
 	Frequency        *prometheus.GaugeVec
+	TotalPowerFactor *prometheus.GaugeVec
 }
 
 func New() Exporter {
@@ -51,11 +52,19 @@ func New() Exporter {
 		Help:      "Frequency in Hz",
 	}, []string{"device"})
 
+	exporter.TotalPowerFactor = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "siemens",
+		Subsystem: "pac3100",
+		Name:      "total_power_factor",
+		Help:      "Total Power Factor",
+	}, []string{"device"})
+
 	prometheus.MustRegister(exporter.Voltage)
 	prometheus.MustRegister(exporter.Current)
 	prometheus.MustRegister(exporter.ApparantPower)
 	prometheus.MustRegister(exporter.ActivePower)
 	prometheus.MustRegister(exporter.Frequency)
+	prometheus.MustRegister(exporter.TotalPowerFactor)
 
 	return exporter
 }
@@ -82,4 +91,5 @@ func (e Exporter) SetMeasurements(measurement scraper.Measurements, deviceName s
 	e.ActivePower.WithLabelValues(deviceName, "C").Set(float64(measurement.ActivePowerC))
 
 	e.Frequency.WithLabelValues(deviceName).Set(float64(measurement.Frequency))
+	e.TotalPowerFactor.WithLabelValues(deviceName).Set(float64(measurement.TotalPowerFactor))
 }

scraper/scraper.go

@@ -31,6 +31,7 @@ type Measurements struct {
 	ActivePowerB     float32
 	ActivePowerC     float32
 	Frequency        float32
+	TotalPowerFactor float32
 }
 
 func New(address string, logger zerolog.Logger) (*Scraper, error) {
@@ -139,6 +140,11 @@ func (s *Scraper) GetMeasurments() (Measurements, error) {
 		s.logger.Err(err)
 	}
 
+	measurement.TotalPowerFactor, err = s.GetTotalPowerFactor()
+	if err != nil {
+		s.logger.Err(err)
+	}
+
 	return measurement, nil
 }
 
@@ -286,6 +292,15 @@ func (s *Scraper) GetFrequency() (float32, error) {
 	return Float32fromBytes(results), nil
 }
 
+// no Unit
+func (s *Scraper) GetTotalPowerFactor() (float32, error) {
+	results, err := s.modbus.ReadInputRegistersBytes(126, 53, 2)
+	if err != nil {
+		return 0, fmt.Errorf("reading Total Power Factor: %w", err)
+	}
+	return Float32fromBytes(results), nil
+}
+
 func Float32fromBytes(bytes []byte) float32 {
 	bits := binary.BigEndian.Uint32(bytes)
 	float := math.Float32frombits(bits)