diff --git a/kn/constants.go b/kn/constants.go
index 5ab2fce..07b41f6 100644
--- a/kn/constants.go
+++ b/kn/constants.go
@@ -8,13 +8,22 @@ const REG_MODE = 2
 const REG_TARGET_TEMP = 3
 const REG_CURRENT_TEMP = 4
 
+const REG_AIRFLOW = 65
+const REG_AC_TARGET_TEMP = 69
+const REG_AC_TARGET_FAN_MODE = 73
+const REG_SERIAL_CONFIG = 77
+const REG_SLAVE_ID = 78
+const REG_EFFICIENCY = 79
+const REG_SYSTEM_ENABLED = 81
+const REG_SYS_HVAC_MODE = 82
+
 type FanMode byte
 
-const FAN_OFF FanMode = 0x00
-const FAN_LOW FanMode = 0x10
-const FAN_MED FanMode = 0x20
-const FAN_HIGH FanMode = 0x30
-const FAN_AUTO FanMode = 0x40
+const FAN_OFF FanMode = 0
+const FAN_LOW FanMode = 1
+const FAN_MED FanMode = 2
+const FAN_HIGH FanMode = 3
+const FAN_AUTO FanMode = 4
 
 type HvacMode byte
 
@@ -39,3 +48,28 @@ var HvacModes = bimap.New(map[interface{}]interface{}{
 	"underfloor air cooling": MODE_UNDERFLOOR_AIR_COOLING,
 	"underfloor air heating": MODE_UNDERFLOOR_AIR_HEATING,
 })
+
+type ACMachine int
+
+const ACMachines = 4
+
+const AC1 ACMachine = 1
+const AC2 ACMachine = 2
+const AC3 ACMachine = 3
+const AC4 ACMachine = 4
+
+func FanMode2Str(fm FanMode) string {
+	st, ok := FanModes.GetInverse(fm)
+	if !ok {
+		st = "unknown"
+	}
+	return st.(string)
+}
+
+func HvacMode2Str(hm HvacMode) string {
+	st, ok := HvacModes.GetInverse(hm)
+	if !ok {
+		st = "unknown"
+	}
+	return st.(string)
+}
diff --git a/kn/sys.go b/kn/sys.go
new file mode 100644
index 0000000..824b50d
--- /dev/null
+++ b/kn/sys.go
@@ -0,0 +1,156 @@
+package kn
+
+import "errors"
+
+type SysConfig struct {
+	Watcher Watcher
+}
+
+type Sys struct {
+	SysConfig
+	OnACAirflowChange       func(ac ACMachine)
+	OnACTargetTempChange    func(ac ACMachine)
+	OnACTargetFanModeChange func(ac ACMachine)
+	OnEfficiencyChange      func()
+	OnSystemEnabledChange   func()
+	OnHvacModeChange        func()
+}
+
+var ErrUnknownSerialConfig = errors.New("Uknown serial configuration")
+
+func NewSys(config *SysConfig) *Sys {
+	s := &Sys{
+		SysConfig: *config,
+	}
+	for n := byte(0); n < ACMachines; n++ {
+		func(ac ACMachine) {
+			s.Watcher.RegisterCallback(uint16(REG_AIRFLOW+ac-1), func(address uint16) {
+				if s.OnACAirflowChange != nil {
+					s.OnACAirflowChange(ac)
+				}
+			})
+			s.Watcher.RegisterCallback(uint16(REG_AC_TARGET_TEMP+ac-1), func(address uint16) {
+				if s.OnACTargetTempChange != nil {
+					s.OnACTargetTempChange(ac)
+				}
+			})
+			s.Watcher.RegisterCallback(uint16(REG_AC_TARGET_FAN_MODE+ac-1), func(address uint16) {
+				if s.OnACTargetFanModeChange != nil {
+					s.OnACTargetFanModeChange(ac)
+				}
+			})
+		}(ACMachine(n + 1))
+	}
+
+	s.Watcher.RegisterCallback(REG_EFFICIENCY, func(address uint16) {
+		if s.OnEfficiencyChange != nil {
+			s.OnEfficiencyChange()
+		}
+	})
+
+	s.Watcher.RegisterCallback(REG_SYSTEM_ENABLED, func(address uint16) {
+		if s.OnSystemEnabledChange != nil {
+			s.OnSystemEnabledChange()
+		}
+	})
+
+	s.Watcher.RegisterCallback(REG_SYS_HVAC_MODE, func(address uint16) {
+		if s.OnHvacModeChange != nil {
+			s.OnHvacModeChange()
+		}
+	})
+
+	return s
+}
+
+func (s *Sys) ReadRegister(n int) (int, error) {
+	r, err := s.Watcher.ReadRegister(uint16(n))
+	if err != nil || len(r) != 2 {
+		return 0, nil
+	}
+	return int(r[1]), nil
+}
+
+func (s *Sys) GetAirflow(ac ACMachine) (int, error) {
+	r, err := s.ReadRegister(REG_AIRFLOW + int(ac) - 1)
+	if err != nil {
+		return 0, err
+	}
+	return r, nil
+}
+
+func (s *Sys) GetMachineTargetTemp(ac ACMachine) (float32, error) {
+	r, err := s.ReadRegister(REG_AC_TARGET_TEMP + int(ac) - 1)
+	if err != nil {
+		return 0, err
+	}
+	return reg2temp(uint16(r)), nil
+}
+
+func (s *Sys) GetTargetFanMode(ac ACMachine) (FanMode, error) {
+	r, err := s.ReadRegister(REG_AC_TARGET_FAN_MODE + int(ac) - 1)
+	if err != nil {
+		return 0, err
+	}
+	return FanMode(r), nil
+}
+
+func (s *Sys) GetBaudRate() (int, error) {
+	r, err := s.ReadRegister(REG_SERIAL_CONFIG)
+	if err != nil {
+		return 0, err
+	}
+	switch r {
+	case 2, 6:
+		return 9600, nil
+	case 3, 7:
+		return 19200, nil
+	}
+	return 0, ErrUnknownSerialConfig
+}
+
+func (s *Sys) GetParity() (string, error) {
+	r, err := s.ReadRegister(REG_SERIAL_CONFIG)
+	if err != nil {
+		return "", err
+	}
+	switch r {
+	case 2, 3:
+		return "even", nil
+	case 6, 7:
+		return "none", nil
+	}
+	return "", ErrUnknownSerialConfig
+}
+
+func (s *Sys) GetSlaveID() (int, error) {
+	r, err := s.ReadRegister(REG_SLAVE_ID)
+	if err != nil {
+		return 0, err
+	}
+	return r, nil
+}
+
+func (s *Sys) GetEfficiency() (int, error) {
+	r, err := s.ReadRegister(REG_EFFICIENCY)
+	if err != nil {
+		return 0, err
+	}
+	return r, nil
+}
+
+func (s *Sys) GetSystemEnabled() (bool, error) {
+	r, err := s.ReadRegister(REG_SYSTEM_ENABLED)
+	if err != nil {
+		return false, err
+	}
+	return r != 0, nil
+}
+
+func (s *Sys) GetSystemHVACMode() (HvacMode, error) {
+	r, err := s.ReadRegister(REG_SYS_HVAC_MODE)
+	if err != nil {
+		return 0, err
+	}
+	return HvacMode(r), nil
+}
diff --git a/kn/zone.go b/kn/zone.go
index 9c94e05..20b1ab5 100644
--- a/kn/zone.go
+++ b/kn/zone.go
@@ -93,7 +93,7 @@ func (z *Zone) IsOn() (bool, error) {
 		return false, err
 	}
 
-	return r1&uint16(0x1) != 0, nil
+	return r1&0x1 != 0, nil
 }
 
 func (z *Zone) IsPresent() (bool, error) {
@@ -102,7 +102,7 @@ func (z *Zone) IsPresent() (bool, error) {
 		return false, err
 	}
 
-	return r1&uint16(0x2) != 0, nil
+	return r1&0x2 != 0, nil
 }
 
 func (z *Zone) GetCurrentTemperature() (float32, error) {
@@ -111,7 +111,7 @@ func (z *Zone) GetCurrentTemperature() (float32, error) {
 		return 0.0, err
 	}
 
-	return float32(r4) / 2.0, nil
+	return reg2temp(r4), nil
 }
 
 func (z *Zone) GetTargetTemperature() (float32, error) {
@@ -119,7 +119,7 @@ func (z *Zone) GetTargetTemperature() (float32, error) {
 	if err != nil {
 		return 0.0, err
 	}
-	return float32(r3) / 2.0, nil
+	return reg2temp(r3), nil
 }
 
 func (z *Zone) GetFanMode() (FanMode, error) {
@@ -127,7 +127,7 @@ func (z *Zone) GetFanMode() (FanMode, error) {
 	if err != nil {
 		return 0, err
 	}
-	return (FanMode)(r2 & 0x00F0), nil
+	return (FanMode)(r2&0x00F0) >> 4, nil
 }
 
 func (z *Zone) GetHvacMode() (HvacMode, error) {
@@ -137,3 +137,7 @@ func (z *Zone) GetHvacMode() (HvacMode, error) {
 	}
 	return (HvacMode)(r2 & 0x000F), nil
 }
+
+func reg2temp(r uint16) float32 {
+	return float32(0x00FF&r) / 2.0
+}
diff --git a/main.go b/main.go
index c2cc9c9..772c49c 100644
--- a/main.go
+++ b/main.go
@@ -83,25 +83,52 @@ func main() {
 
 	nodeName := "topFloors"
 
-	getTopic := func(zoneNum int, subtopic string) string {
+	getZoneTopic := func(zoneNum int, subtopic string) string {
 		return fmt.Sprintf("%s/%s/zone%d/%s", *prefix, nodeName, zoneNum, subtopic)
 	}
 
-	w := watcher.New(&watcher.Config{
+	getSysTopic := func(subtopic string) string {
+		return fmt.Sprintf("%s/%s/sys/%s", *prefix, nodeName, subtopic)
+	}
+
+	getACTopic := func(ac kn.ACMachine, subtopic string) string {
+		return getSysTopic(fmt.Sprintf("ac%d/%s", ac, subtopic))
+	}
+
+	registerReader := buildReader(handler, client)
+
+	zw := watcher.New(&watcher.Config{
 		Address:      1,
 		Quantity:     64,
 		RegisterSize: 2,
 		SlaveID:      49,
-		Read:         buildReader(handler, client),
+		Read:         registerReader,
 	})
 
-	err = w.Poll()
+	sysw := watcher.New(&watcher.Config{
+		Address:      kn.REG_AIRFLOW,
+		Quantity:     18,
+		RegisterSize: 2,
+		SlaveID:      49,
+		Read:         registerReader,
+	})
+
+	err = zw.Poll()
 	if err != nil {
 		fmt.Println(err)
 		return
 	}
 
-	zones, err := getActiveZones(w)
+	err = sysw.Poll()
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	zones, err := getActiveZones(zw)
+	sys := kn.NewSys(&kn.SysConfig{
+		Watcher: sysw,
+	})
 
 	connOpts := MQTT.NewClientOptions().AddBroker(*server).SetClientID(*clientid).SetCleanSession(true)
 	if *username != "" {
@@ -117,35 +144,92 @@ func main() {
 		/* 		if token := c.Subscribe(*topic, byte(*qos), onMessageReceived); token.Wait() && token.Error() != nil {
 			panic(token.Error())
 		} */
-		w.TriggerCallbacks()
-	}
+		zw.TriggerCallbacks()
+		sysw.TriggerCallbacks()
+		bauds, err := sys.GetBaudRate()
+		if err != nil {
+			log.Printf("Error reading configured serial baud rate: %s", err)
+		}
+		parity, err := sys.GetParity()
+		if err != nil {
+			log.Printf("Error reading configured serial parity: %s", err)
+		}
+		slaveID, err := sys.GetSlaveID()
+		if err != nil {
+			log.Printf("Error reading configured modbus slave ID: %s", err)
+		}
+		c.Publish(getSysTopic("serialBaud"), 0, false, strconv.Itoa(bauds))
+		c.Publish(getSysTopic("serialParity"), 0, false, parity)
+		c.Publish(getSysTopic("slaveId"), 0, false, slaveID)
 
+	}
 	mqttClient := MQTT.NewClient(connOpts)
 
 	for _, zone := range zones {
 		zone := zone
 		zone.OnCurrentTempChange = func(currentTemp float32) {
-			mqttClient.Publish(getTopic(zone.ZoneNumber, "currentTemperature"), 0, false, fmt.Sprintf("%g", currentTemp))
+			mqttClient.Publish(getZoneTopic(zone.ZoneNumber, "currentTemp"), 0, false, fmt.Sprintf("%g", currentTemp))
 		}
 		zone.OnTargetTempChange = func(targetTemp float32) {
-			mqttClient.Publish(getTopic(zone.ZoneNumber, "targetTemperature"), 0, false, fmt.Sprintf("%g", targetTemp))
+			mqttClient.Publish(getZoneTopic(zone.ZoneNumber, "targetTemp"), 0, false, fmt.Sprintf("%g", targetTemp))
 		}
 		zone.OnFanModeChange = func(fanMode kn.FanMode) {
-			fanModeStr, found := kn.FanModes.GetInverse(fanMode)
-			if !found {
-				log.Printf("Unknown fan mode %d", fanMode)
-			}
-			mqttClient.Publish(getTopic(zone.ZoneNumber, "fanMode"), 0, false, fanModeStr)
+			mqttClient.Publish(getZoneTopic(zone.ZoneNumber, "fanMode"), 0, false, kn.FanMode2Str(fanMode))
 		}
 		zone.OnHvacModeChange = func(hvacMode kn.HvacMode) {
-			hvacModeStr, found := kn.HvacModes.GetInverse(hvacMode)
-			if !found {
-				log.Printf("Unknown hvac mode %d", hvacMode)
-			}
-			mqttClient.Publish(getTopic(zone.ZoneNumber, "hvacMode"), 0, false, hvacModeStr)
+			mqttClient.Publish(getZoneTopic(zone.ZoneNumber, "hvacMode"), 0, false, kn.HvacMode2Str(hvacMode))
 		}
 	}
 
+	sys.OnACAirflowChange = func(ac kn.ACMachine) {
+		airflow, err := sys.GetAirflow(ac)
+		if err != nil {
+			log.Printf("Error reading airflow of AC %d: %s", ac, err)
+			return
+		}
+		mqttClient.Publish(getACTopic(ac, "airflow"), 0, false, strconv.Itoa(airflow))
+	}
+	sys.OnACTargetTempChange = func(ac kn.ACMachine) {
+		targetTemp, err := sys.GetMachineTargetTemp(ac)
+		if err != nil {
+			log.Printf("Error reading target temp of AC %d: %s", ac, err)
+			return
+		}
+		mqttClient.Publish(getACTopic(ac, "targetTemp"), 0, false, fmt.Sprintf("%g", targetTemp))
+	}
+	sys.OnACTargetFanModeChange = func(ac kn.ACMachine) {
+		targetAirflow, err := sys.GetTargetFanMode(ac)
+		if err != nil {
+			log.Printf("Error reading target airflow of AC %d: %s", ac, err)
+			return
+		}
+		mqttClient.Publish(getACTopic(ac, "fanMode"), 0, false, kn.FanMode2Str(targetAirflow))
+	}
+	sys.OnEfficiencyChange = func() {
+		efficiency, err := sys.GetEfficiency()
+		if err != nil {
+			log.Printf("Error reading efficiency value: %s", err)
+			return
+		}
+		mqttClient.Publish(getSysTopic("efficiency"), 0, false, strconv.Itoa(efficiency))
+	}
+	sys.OnSystemEnabledChange = func() {
+		enabled, err := sys.GetSystemEnabled()
+		if err != nil {
+			log.Printf("Error reading enabled value: %s", err)
+			return
+		}
+		mqttClient.Publish(getSysTopic("enabled"), 0, false, fmt.Sprintf("%t", enabled))
+	}
+	sys.OnHvacModeChange = func() {
+		mode, err := sys.GetSystemHVACMode()
+		if err != nil {
+			log.Printf("Error reading hvac mode: %s", err)
+			return
+		}
+		mqttClient.Publish(getSysTopic("hvacMode"), 0, false, kn.HvacMode2Str(mode))
+	}
+
 	if token := mqttClient.Connect(); token.Wait() && token.Error() != nil {
 		panic(token.Error())
 	} else {
@@ -156,9 +240,14 @@ func main() {
 
 	go func() {
 		for range ticker.C {
-			err := w.Poll()
+			err := zw.Poll()
 			if err != nil {
-				log.Printf("Error polling modbus: %s\n", err)
+				log.Printf("Error polling zones over modbus: %s\n", err)
+			}
+
+			err = sysw.Poll()
+			if err != nil {
+				log.Printf("Error polling system config over modbus: %s\n", err)
 			}
 		}
 	}()