diff --git a/CMakeLists.txt b/CMakeLists.txt
index c29550c..2933ed8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,6 +10,9 @@ idf_component_register(
         "src/decode.cpp"
         "src/device.cpp"
         "src/dt1.cpp"
+        "src/dt4.cpp"
+        "src/dt5.cpp"
+        "src/dt6.cpp"
         "src/dt8.cpp"
         "src/sequence.cpp"
         "src/sequence_store.cpp"
diff --git a/include/dali.hpp b/include/dali.hpp
index 58964b9..f7e5117 100644
--- a/include/dali.hpp
+++ b/include/dali.hpp
@@ -11,6 +11,9 @@
 #include "decode.hpp"
 #include "device.hpp"
 #include "dt1.hpp"
+#include "dt4.hpp"
+#include "dt5.hpp"
+#include "dt6.hpp"
 #include "dt8.hpp"
 #include "addr.hpp"
 #include "gateway_cloud.hpp"
@@ -46,11 +49,15 @@ class Dali {
   DaliBase base;
   DaliDecode decode;
   DaliDT1 dt1;
+  DaliDT4 dt4;
+  DaliDT5 dt5;
+  DaliDT6 dt6;
   DaliDT8 dt8;
   DaliAddr addr;
 
   explicit Dali(DaliComm& comm, int g = 0, const std::string& n = "dali1")
-      : name(n), gw(g), base(comm), decode(), dt1(base), dt8(base), addr(base) {}
+      : name(n), gw(g), base(comm), decode(), dt1(base), dt4(base), dt5(base), dt6(base),
+        dt8(base), addr(base) {}
 
   void open() {}
   void close() {}
diff --git a/include/dali_define.hpp b/include/dali_define.hpp
index 0c4d2f3..8dd86a2 100644
--- a/include/dali_define.hpp
+++ b/include/dali_define.hpp
@@ -92,6 +92,65 @@
 #define DALI_CMD_SPECIAL_SET_DTR_1 0xC3
 #define DALI_CMD_SPECIAL_SET_DTR_2 0xC5
 
+// DT4 commands and queries
+#define DALI_CMD_DT4_REFERENCE_SYSTEM_POWER 0xE0
+#define DALI_CMD_DT4_SELECT_DIMMING_CURVE 0xE1
+#define DALI_CMD_DT4_QUERY_DIMMING_CURVE 0xEE
+#define DALI_CMD_DT4_QUERY_DIMMER_STATUS 0xEF
+#define DALI_CMD_DT4_QUERY_FEATURES 0xF0
+#define DALI_CMD_DT4_QUERY_FAILURE_STATUS 0xF1
+#define DALI_CMD_DT4_QUERY_DIMMER_TEMPERATURE 0xF2
+#define DALI_CMD_DT4_QUERY_RMS_SUPPLY_VOLTAGE 0xF3
+#define DALI_CMD_DT4_QUERY_SUPPLY_FREQUENCY 0xF4
+#define DALI_CMD_DT4_QUERY_RMS_LOAD_VOLTAGE 0xF5
+#define DALI_CMD_DT4_QUERY_RMS_LOAD_CURRENT 0xF6
+#define DALI_CMD_DT4_QUERY_REAL_LOAD_POWER 0xF7
+#define DALI_CMD_DT4_QUERY_LOAD_RATING 0xF8
+#define DALI_CMD_DT4_QUERY_REFERENCE_RUNNING 0xF9
+#define DALI_CMD_DT4_QUERY_REFERENCE_MEASUREMENT_FAILED 0xFA
+#define DALI_CMD_DT4_QUERY_EXTENDED_VERSION 0xFF
+
+// DT5 commands and queries
+#define DALI_CMD_DT5_SET_OUTPUT_RANGE_1_TO_10V 0xE0
+#define DALI_CMD_DT5_SET_OUTPUT_RANGE_0_TO_10V 0xE1
+#define DALI_CMD_DT5_SWITCH_ON_INTERNAL_PULL_UP 0xE2
+#define DALI_CMD_DT5_SWITCH_OFF_INTERNAL_PULL_UP 0xE3
+#define DALI_CMD_DT5_STORE_DTR_AS_PHYSICAL_MINIMUM 0xE4
+#define DALI_CMD_DT5_SELECT_DIMMING_CURVE 0xE5
+#define DALI_CMD_DT5_RESET_CONVERTER_SETTINGS 0xE6
+#define DALI_CMD_DT5_QUERY_DIMMING_CURVE 0xEE
+#define DALI_CMD_DT5_QUERY_OUTPUT_LEVEL 0xEF
+#define DALI_CMD_DT5_QUERY_CONVERTER_FEATURES 0xF0
+#define DALI_CMD_DT5_QUERY_FAILURE_STATUS 0xF1
+#define DALI_CMD_DT5_QUERY_CONVERTER_STATUS 0xF2
+#define DALI_CMD_DT5_QUERY_EXTENDED_VERSION 0xFF
+
+// DT6 commands and queries
+#define DALI_CMD_DT6_REFERENCE_SYSTEM_POWER 0xE0
+#define DALI_CMD_DT6_ENABLE_CURRENT_PROTECTOR 0xE1
+#define DALI_CMD_DT6_DISABLE_CURRENT_PROTECTOR 0xE2
+#define DALI_CMD_DT6_SELECT_DIMMING_CURVE 0xE3
+#define DALI_CMD_DT6_STORE_DTR_AS_FAST_FADE_TIME 0xE4
+#define DALI_CMD_DT6_QUERY_GEAR_TYPE 0xED
+#define DALI_CMD_DT6_QUERY_DIMMING_CURVE 0xEE
+#define DALI_CMD_DT6_QUERY_POSSIBLE_OPERATING_MODES 0xEF
+#define DALI_CMD_DT6_QUERY_FEATURES 0xF0
+#define DALI_CMD_DT6_QUERY_FAILURE_STATUS 0xF1
+#define DALI_CMD_DT6_QUERY_SHORT_CIRCUIT 0xF2
+#define DALI_CMD_DT6_QUERY_OPEN_CIRCUIT 0xF3
+#define DALI_CMD_DT6_QUERY_LOAD_DECREASE 0xF4
+#define DALI_CMD_DT6_QUERY_LOAD_INCREASE 0xF5
+#define DALI_CMD_DT6_QUERY_CURRENT_PROTECTOR_ACTIVE 0xF6
+#define DALI_CMD_DT6_QUERY_THERMAL_SHUTDOWN 0xF7
+#define DALI_CMD_DT6_QUERY_THERMAL_OVERLOAD 0xF8
+#define DALI_CMD_DT6_QUERY_REFERENCE_RUNNING 0xF9
+#define DALI_CMD_DT6_QUERY_REFERENCE_MEASUREMENT_FAILED 0xFA
+#define DALI_CMD_DT6_QUERY_CURRENT_PROTECTOR_ENABLED 0xFB
+#define DALI_CMD_DT6_QUERY_OPERATING_MODE 0xFC
+#define DALI_CMD_DT6_QUERY_FAST_FADE_TIME 0xFD
+#define DALI_CMD_DT6_QUERY_MIN_FAST_FADE_TIME 0xFE
+#define DALI_CMD_DT6_QUERY_EXTENDED_VERSION 0xFF
+
 // DT8 commands and queries
 #define DALI_CMD_DT8_STORE_DTR_AS_COLORX 0xE0
 #define DALI_CMD_DT8_STORE_DTR_AS_COLORY 0xE1
diff --git a/include/device.hpp b/include/device.hpp
index 58a2fc0..449d19f 100644
--- a/include/device.hpp
+++ b/include/device.hpp
@@ -17,6 +17,9 @@ struct DaliLongAddress {
 
 struct DaliDeviceCapabilities {
   std::optional<bool> supportsDt1;
+  std::optional<bool> supportsDt4;
+  std::optional<bool> supportsDt5;
+  std::optional<bool> supportsDt6;
   std::optional<bool> supportsDt8;
 
   static DaliDeviceCapabilities fromJson(const DaliValue::Object* json);
diff --git a/include/dt4.hpp b/include/dt4.hpp
new file mode 100644
index 0000000..96d0763
--- /dev/null
+++ b/include/dt4.hpp
@@ -0,0 +1,126 @@
+#pragma once
+
+#include "base.hpp"
+
+#include <optional>
+
+class DaliDT4DimmerStatus {
+ public:
+  explicit DaliDT4DimmerStatus(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool leadingEdgeModeRunning() const { return bit(0x01); }
+  bool trailingEdgeModeRunning() const { return bit(0x02); }
+  bool referenceMeasurementRunning() const { return bit(0x04); }
+  bool nonLogarithmicDimmingCurveActive() const { return bit(0x10); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT4Features {
+ public:
+  DaliDT4Features(int raw1, int raw2, int raw3)
+      : raw1_(raw1 & 0xFF), raw2_(raw2 & 0xFF), raw3_(raw3 & 0xFF) {}
+
+  int raw1() const { return raw1_; }
+  int raw2() const { return raw2_; }
+  int raw3() const { return raw3_; }
+
+  bool canQueryLoadOverCurrentShutdown() const { return bit(raw1_, 0x01); }
+  bool canQueryOpenCircuitDetection() const { return bit(raw1_, 0x02); }
+  bool canQueryLoadDecrease() const { return bit(raw1_, 0x04); }
+  bool canQueryLoadIncrease() const { return bit(raw1_, 0x08); }
+  bool canQueryThermalShutdown() const { return bit(raw1_, 0x20); }
+  bool canQueryThermalOverloadReduction() const { return bit(raw1_, 0x40); }
+  bool physicalSelectionSupported() const { return bit(raw1_, 0x80); }
+
+  bool canQueryTemperature() const { return bit(raw2_, 0x01); }
+  bool canQuerySupplyVoltage() const { return bit(raw2_, 0x02); }
+  bool canQuerySupplyFrequency() const { return bit(raw2_, 0x04); }
+  bool canQueryLoadVoltage() const { return bit(raw2_, 0x08); }
+  bool canQueryLoadCurrent() const { return bit(raw2_, 0x10); }
+  bool canQueryRealLoadPower() const { return bit(raw2_, 0x20); }
+  bool canQueryLoadRating() const { return bit(raw2_, 0x40); }
+  bool canQueryCurrentOverloadReduction() const { return bit(raw2_, 0x80); }
+
+  bool canSelectNonLogarithmicDimmingCurve() const { return bit(raw3_, 0x08); }
+  bool canQueryUnsuitableLoad() const { return bit(raw3_, 0x80); }
+  int dimmingMethodCode() const { return raw3_ & 0x03; }
+
+ private:
+  int raw1_ = 0;
+  int raw2_ = 0;
+  int raw3_ = 0;
+
+  static bool bit(int value, int mask) { return (value & mask) != 0; }
+};
+
+class DaliDT4FailureStatus {
+ public:
+  DaliDT4FailureStatus(int raw1, int raw2)
+      : raw1_(raw1 & 0xFF), raw2_(raw2 & 0xFF) {}
+
+  int raw1() const { return raw1_; }
+  int raw2() const { return raw2_; }
+
+  bool loadOverCurrentShutdown() const { return bit(raw1_, 0x01); }
+  bool openCircuitDetected() const { return bit(raw1_, 0x02); }
+  bool loadDecreaseDetected() const { return bit(raw1_, 0x04); }
+  bool loadIncreaseDetected() const { return bit(raw1_, 0x08); }
+  bool thermalShutdown() const { return bit(raw1_, 0x20); }
+  bool thermalOverloadReduction() const { return bit(raw1_, 0x40); }
+  bool referenceMeasurementFailed() const { return bit(raw1_, 0x80); }
+
+  bool loadUnsuitableForSelectedMethod() const { return bit(raw2_, 0x01); }
+  bool supplyVoltageOutOfLimits() const { return bit(raw2_, 0x02); }
+  bool supplyFrequencyOutOfLimits() const { return bit(raw2_, 0x04); }
+  bool loadVoltageOutOfLimits() const { return bit(raw2_, 0x08); }
+  bool loadCurrentOverloadReduction() const { return bit(raw2_, 0x10); }
+
+ private:
+  int raw1_ = 0;
+  int raw2_ = 0;
+
+  static bool bit(int value, int mask) { return (value & mask) != 0; }
+};
+
+class DaliDT4 {
+ public:
+  explicit DaliDT4(DaliBase& base);
+
+  bool enableDT4();
+  bool referenceSystemPower(int a);
+  bool selectDimmingCurve(int a, int curve);
+
+  std::optional<int> getDimmingCurve(int a);
+  std::optional<DaliDT4DimmerStatus> getDimmerStatus(int a);
+  std::optional<DaliDT4Features> getFeatures(int a);
+  std::optional<DaliDT4FailureStatus> getFailureStatus(int a);
+  std::optional<int> getDimmerTemperatureRaw(int a);
+  std::optional<int> getDimmerTemperatureCelsius(int a);
+  std::optional<int> getRmsSupplyVoltageRaw(int a);
+  std::optional<double> getRmsSupplyVoltageVolts(int a);
+  std::optional<int> getSupplyFrequencyRaw(int a);
+  std::optional<double> getSupplyFrequencyHertz(int a);
+  std::optional<int> getRmsLoadVoltageRaw(int a);
+  std::optional<double> getRmsLoadVoltageVolts(int a);
+  std::optional<int> getRmsLoadCurrentRaw(int a);
+  std::optional<double> getRmsLoadCurrentPercent(int a);
+  std::optional<int> getRealLoadPowerRaw(int a);
+  std::optional<double> getRealLoadPowerWatts(int a);
+  std::optional<int> getLoadRatingRaw(int a);
+  std::optional<double> getLoadRatingAmps(int a);
+  std::optional<bool> isReferenceRunning(int a);
+  std::optional<bool> isReferenceMeasurementFailed(int a);
+  std::optional<int> getExtendedVersion(int a);
+
+ private:
+  DaliBase& base_;
+
+  bool enable();
+  static int addrOf(int a);
+  std::optional<int> query(int a, int code);
+  std::optional<bool> queryYesNo(int a, int code);
+};
\ No newline at end of file
diff --git a/include/dt5.hpp b/include/dt5.hpp
new file mode 100644
index 0000000..74445b9
--- /dev/null
+++ b/include/dt5.hpp
@@ -0,0 +1,78 @@
+#pragma once
+
+#include "base.hpp"
+
+#include <optional>
+
+class DaliDT5ConverterFeatures {
+ public:
+  explicit DaliDT5ConverterFeatures(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool outputRange0To10VSelectable() const { return bit(0x01); }
+  bool internalPullUpSelectable() const { return bit(0x02); }
+  bool outputFaultDetectionSelectable() const { return bit(0x04); }
+  bool mainsRelay() const { return bit(0x08); }
+  bool outputLevelQueryable() const { return bit(0x10); }
+  bool nonLogarithmicDimmingCurveSupported() const { return bit(0x20); }
+  bool physicalSelectionByOutputLossSupported() const { return bit(0x40); }
+  bool physicalSelectionSwitchSupported() const { return bit(0x80); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT5FailureStatus {
+ public:
+  explicit DaliDT5FailureStatus(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool outputFaultDetected() const { return (raw_ & 0x01) != 0; }
+
+ private:
+  int raw_ = 0;
+};
+
+class DaliDT5ConverterStatus {
+ public:
+  explicit DaliDT5ConverterStatus(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool zeroToTenVoltOperation() const { return (raw_ & 0x01) != 0; }
+  bool internalPullUpOn() const { return (raw_ & 0x02) != 0; }
+  bool nonLogarithmicDimmingCurveActive() const { return (raw_ & 0x04) != 0; }
+
+ private:
+  int raw_ = 0;
+};
+
+class DaliDT5 {
+ public:
+  explicit DaliDT5(DaliBase& base);
+
+  bool enableDT5();
+  bool setOutputRange1To10V(int a);
+  bool setOutputRange0To10V(int a);
+  bool switchOnInternalPullUp(int a);
+  bool switchOffInternalPullUp(int a);
+  bool storePhysicalMinimum(int a, int level);
+  bool selectDimmingCurve(int a, int curve);
+  bool resetConverterSettings(int a);
+
+  std::optional<int> getDimmingCurve(int a);
+  std::optional<int> getOutputLevelRaw(int a);
+  std::optional<double> getOutputLevelVolts(int a);
+  std::optional<DaliDT5ConverterFeatures> getConverterFeatures(int a);
+  std::optional<DaliDT5FailureStatus> getFailureStatus(int a);
+  std::optional<DaliDT5ConverterStatus> getConverterStatus(int a);
+  std::optional<int> getExtendedVersion(int a);
+
+ private:
+  DaliBase& base_;
+
+  bool enable();
+  static int addrOf(int a);
+  bool send(int a, int code, bool twice = false);
+  std::optional<int> query(int a, int code);
+};
\ No newline at end of file
diff --git a/include/dt6.hpp b/include/dt6.hpp
new file mode 100644
index 0000000..adf1d49
--- /dev/null
+++ b/include/dt6.hpp
@@ -0,0 +1,130 @@
+#pragma once
+
+#include "base.hpp"
+
+#include <optional>
+
+class DaliDT6GearType {
+ public:
+  explicit DaliDT6GearType(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool ledPowerSupplyIntegrated() const { return bit(0x01); }
+  bool ledModuleIntegrated() const { return bit(0x02); }
+  bool acSupplyPossible() const { return bit(0x04); }
+  bool dcSupplyPossible() const { return bit(0x08); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT6OperatingModes {
+ public:
+  explicit DaliDT6OperatingModes(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool pwmModePossible() const { return bit(0x01); }
+  bool amModePossible() const { return bit(0x02); }
+  bool currentControlledOutput() const { return bit(0x04); }
+  bool highCurrentPulseMode() const { return bit(0x08); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT6Features {
+ public:
+  explicit DaliDT6Features(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool canQueryShortCircuit() const { return bit(0x01); }
+  bool canQueryOpenCircuit() const { return bit(0x02); }
+  bool canQueryLoadDecrease() const { return bit(0x04); }
+  bool canQueryLoadIncrease() const { return bit(0x08); }
+  bool canQueryCurrentProtector() const { return bit(0x10); }
+  bool canQueryThermalShutdown() const { return bit(0x20); }
+  bool canQueryThermalOverloadReduction() const { return bit(0x40); }
+  bool physicalSelectionSupported() const { return bit(0x80); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT6FailureStatus {
+ public:
+  explicit DaliDT6FailureStatus(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool shortCircuit() const { return bit(0x01); }
+  bool openCircuit() const { return bit(0x02); }
+  bool loadDecrease() const { return bit(0x04); }
+  bool loadIncrease() const { return bit(0x08); }
+  bool currentProtectorActive() const { return bit(0x10); }
+  bool thermalShutdown() const { return bit(0x20); }
+  bool thermalOverloadReduction() const { return bit(0x40); }
+  bool referenceMeasurementFailed() const { return bit(0x80); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT6OperatingMode {
+ public:
+  explicit DaliDT6OperatingMode(int raw) : raw_(raw & 0xFF) {}
+
+  int raw() const { return raw_; }
+  bool pwmModeActive() const { return bit(0x01); }
+  bool amModeActive() const { return bit(0x02); }
+  bool currentControlledOutput() const { return bit(0x04); }
+  bool highCurrentPulseModeActive() const { return bit(0x08); }
+  bool nonLogarithmicDimmingCurveActive() const { return bit(0x10); }
+
+ private:
+  int raw_ = 0;
+  bool bit(int mask) const { return (raw_ & mask) != 0; }
+};
+
+class DaliDT6 {
+ public:
+  explicit DaliDT6(DaliBase& base);
+
+  bool enableDT6();
+  bool referenceSystemPower(int a);
+  bool enableCurrentProtector(int a);
+  bool disableCurrentProtector(int a);
+  bool selectDimmingCurve(int a, int curve);
+  bool storeFastFadeTime(int a, int value);
+
+  std::optional<DaliDT6GearType> getGearType(int a);
+  std::optional<int> getDimmingCurve(int a);
+  std::optional<DaliDT6OperatingModes> getPossibleOperatingModes(int a);
+  std::optional<DaliDT6Features> getFeatures(int a);
+  std::optional<DaliDT6FailureStatus> getFailureStatus(int a);
+  std::optional<bool> hasShortCircuit(int a);
+  std::optional<bool> hasOpenCircuit(int a);
+  std::optional<bool> hasLoadDecrease(int a);
+  std::optional<bool> hasLoadIncrease(int a);
+  std::optional<bool> isCurrentProtectorActive(int a);
+  std::optional<bool> hasThermalShutDown(int a);
+  std::optional<bool> hasThermalOverload(int a);
+  std::optional<bool> isReferenceRunning(int a);
+  std::optional<bool> isReferenceMeasurementFailed(int a);
+  std::optional<bool> isCurrentProtectorEnabled(int a);
+  std::optional<DaliDT6OperatingMode> getOperatingMode(int a);
+  std::optional<int> getFastFadeTime(int a);
+  std::optional<int> getMinFastFadeTime(int a);
+  std::optional<int> getExtendedVersion(int a);
+
+ private:
+  DaliBase& base_;
+
+  bool enable();
+  static int addrOf(int a);
+  bool send(int a, int code, bool twice = false);
+  std::optional<int> query(int a, int code);
+  std::optional<bool> queryYesNo(int a, int code);
+};
\ No newline at end of file
diff --git a/src/decode.cpp b/src/decode.cpp
index bf08dd0..2b47831 100644
--- a/src/decode.cpp
+++ b/src/decode.cpp
@@ -383,7 +383,10 @@ std::string DaliDecode::whoLabel(int addr, bool even) {
 std::string DaliDecode::deviceTypeName(int v) {
   static const std::map<int, std::string> map = {{0x00, "general control gear"},
                                                   {0x01, "self-contained emergency"},
+                                                  {0x04, "incandescent/halogen"},
+                                                  {0x05, "converter (0/1-10 V)"},
                                                   {0x06, "LED control gear"},
+                                                  {0x07, "switching / OLED control gear"},
                                                   {0x08, "colour control (DT8)"}};
   const auto it = map.find(v);
   return it == map.end() ? "" : it->second;
diff --git a/src/device.cpp b/src/device.cpp
index d424e03..40e7338 100644
--- a/src/device.cpp
+++ b/src/device.cpp
@@ -49,6 +49,9 @@ DaliDeviceCapabilities DaliDeviceCapabilities::fromJson(const DaliValue::Object*
   DaliDeviceCapabilities c;
   if (!json) return c;
   c.supportsDt1 = getObjectBool(*json, "dt1");
+  c.supportsDt4 = getObjectBool(*json, "dt4");
+  c.supportsDt5 = getObjectBool(*json, "dt5");
+  c.supportsDt6 = getObjectBool(*json, "dt6");
   c.supportsDt8 = getObjectBool(*json, "dt8");
   return c;
 }
@@ -56,12 +59,18 @@ DaliDeviceCapabilities DaliDeviceCapabilities::fromJson(const DaliValue::Object*
 DaliValue::Object DaliDeviceCapabilities::toJson() const {
   DaliValue::Object out;
   if (supportsDt1.has_value()) out["dt1"] = supportsDt1.value();
+  if (supportsDt4.has_value()) out["dt4"] = supportsDt4.value();
+  if (supportsDt5.has_value()) out["dt5"] = supportsDt5.value();
+  if (supportsDt6.has_value()) out["dt6"] = supportsDt6.value();
   if (supportsDt8.has_value()) out["dt8"] = supportsDt8.value();
   return out;
 }
 
 void DaliDeviceCapabilities::merge(const DaliDeviceCapabilities& other) {
   if (!supportsDt1.has_value()) supportsDt1 = other.supportsDt1;
+  if (!supportsDt4.has_value()) supportsDt4 = other.supportsDt4;
+  if (!supportsDt5.has_value()) supportsDt5 = other.supportsDt5;
+  if (!supportsDt6.has_value()) supportsDt6 = other.supportsDt6;
   if (!supportsDt8.has_value()) supportsDt8 = other.supportsDt8;
 }
 
diff --git a/src/dt4.cpp b/src/dt4.cpp
new file mode 100644
index 0000000..ad6745a
--- /dev/null
+++ b/src/dt4.cpp
@@ -0,0 +1,147 @@
+#include "dt4.hpp"
+
+#include "dali_define.hpp"
+
+#include <algorithm>
+
+DaliDT4::DaliDT4(DaliBase& base) : base_(base) {}
+
+bool DaliDT4::enable() { return base_.dtSelect(4); }
+
+int DaliDT4::addrOf(int a) { return a * 2 + 1; }
+
+std::optional<int> DaliDT4::query(int a, int code) {
+  if (!enable()) return std::nullopt;
+  return base_.queryCmd(static_cast<uint8_t>(addrOf(a)), static_cast<uint8_t>(code));
+}
+
+std::optional<bool> DaliDT4::queryYesNo(int a, int code) {
+  const auto value = query(a, code);
+  if (!value.has_value()) return std::nullopt;
+  return value.value() != 0;
+}
+
+bool DaliDT4::enableDT4() { return enable(); }
+
+bool DaliDT4::referenceSystemPower(int a) {
+  return enable() && base_.sendExtCmd(addrOf(a), DALI_CMD_DT4_REFERENCE_SYSTEM_POWER) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT4_REFERENCE_SYSTEM_POWER);
+}
+
+bool DaliDT4::selectDimmingCurve(int a, int curve) {
+  const int value = std::clamp(curve, 0, 255);
+  return enable() && base_.setDTR(value) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT4_SELECT_DIMMING_CURVE) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT4_SELECT_DIMMING_CURVE);
+}
+
+std::optional<int> DaliDT4::getDimmingCurve(int a) { return query(a, DALI_CMD_DT4_QUERY_DIMMING_CURVE); }
+
+std::optional<DaliDT4DimmerStatus> DaliDT4::getDimmerStatus(int a) {
+  const auto raw = query(a, DALI_CMD_DT4_QUERY_DIMMER_STATUS);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT4DimmerStatus(raw.value());
+}
+
+std::optional<DaliDT4Features> DaliDT4::getFeatures(int a) {
+  const auto raw1 = query(a, DALI_CMD_DT4_QUERY_FEATURES);
+  if (!raw1.has_value()) return std::nullopt;
+  const auto raw2 = base_.getDTR(a);
+  const auto raw3 = base_.getDTR1(a);
+  if (!raw2.has_value() || !raw3.has_value()) return std::nullopt;
+  return DaliDT4Features(raw1.value(), raw2.value(), raw3.value());
+}
+
+std::optional<DaliDT4FailureStatus> DaliDT4::getFailureStatus(int a) {
+  const auto raw1 = query(a, DALI_CMD_DT4_QUERY_FAILURE_STATUS);
+  if (!raw1.has_value()) return std::nullopt;
+  const auto raw2 = base_.getDTR1(a);
+  if (!raw2.has_value()) return std::nullopt;
+  return DaliDT4FailureStatus(raw1.value(), raw2.value());
+}
+
+std::optional<int> DaliDT4::getDimmerTemperatureRaw(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_DIMMER_TEMPERATURE);
+}
+
+std::optional<int> DaliDT4::getDimmerTemperatureCelsius(int a) {
+  const auto raw = getDimmerTemperatureRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() - 40;
+}
+
+std::optional<int> DaliDT4::getRmsSupplyVoltageRaw(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_RMS_SUPPLY_VOLTAGE);
+}
+
+std::optional<double> DaliDT4::getRmsSupplyVoltageVolts(int a) {
+  const auto raw = getRmsSupplyVoltageRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() * 2.0;
+}
+
+std::optional<int> DaliDT4::getSupplyFrequencyRaw(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_SUPPLY_FREQUENCY);
+}
+
+std::optional<double> DaliDT4::getSupplyFrequencyHertz(int a) {
+  const auto raw = getSupplyFrequencyRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() * 0.5;
+}
+
+std::optional<int> DaliDT4::getRmsLoadVoltageRaw(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_RMS_LOAD_VOLTAGE);
+}
+
+std::optional<double> DaliDT4::getRmsLoadVoltageVolts(int a) {
+  const auto raw = getRmsLoadVoltageRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() * 2.0;
+}
+
+std::optional<int> DaliDT4::getRmsLoadCurrentRaw(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_RMS_LOAD_CURRENT);
+}
+
+std::optional<double> DaliDT4::getRmsLoadCurrentPercent(int a) {
+  const auto raw = getRmsLoadCurrentRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() * 0.5;
+}
+
+std::optional<int> DaliDT4::getRealLoadPowerRaw(int a) {
+  const auto high = query(a, DALI_CMD_DT4_QUERY_REAL_LOAD_POWER);
+  if (!high.has_value()) return std::nullopt;
+  const auto low = base_.getDTR(a);
+  if (!low.has_value()) return std::nullopt;
+  return ((high.value() & 0xFF) << 8) | (low.value() & 0xFF);
+}
+
+std::optional<double> DaliDT4::getRealLoadPowerWatts(int a) {
+  const auto raw = getRealLoadPowerRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFFFF) return std::nullopt;
+  return raw.value() * 0.25;
+}
+
+std::optional<int> DaliDT4::getLoadRatingRaw(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_LOAD_RATING);
+}
+
+std::optional<double> DaliDT4::getLoadRatingAmps(int a) {
+  const auto raw = getLoadRatingRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() * 0.15;
+}
+
+std::optional<bool> DaliDT4::isReferenceRunning(int a) {
+  return queryYesNo(a, DALI_CMD_DT4_QUERY_REFERENCE_RUNNING);
+}
+
+std::optional<bool> DaliDT4::isReferenceMeasurementFailed(int a) {
+  return queryYesNo(a, DALI_CMD_DT4_QUERY_REFERENCE_MEASUREMENT_FAILED);
+}
+
+std::optional<int> DaliDT4::getExtendedVersion(int a) {
+  return query(a, DALI_CMD_DT4_QUERY_EXTENDED_VERSION);
+}
\ No newline at end of file
diff --git a/src/dt5.cpp b/src/dt5.cpp
new file mode 100644
index 0000000..74b689e
--- /dev/null
+++ b/src/dt5.cpp
@@ -0,0 +1,93 @@
+#include "dt5.hpp"
+
+#include "dali_define.hpp"
+
+#include <algorithm>
+
+DaliDT5::DaliDT5(DaliBase& base) : base_(base) {}
+
+bool DaliDT5::enable() { return base_.dtSelect(5); }
+
+int DaliDT5::addrOf(int a) { return a * 2 + 1; }
+
+bool DaliDT5::send(int a, int code, bool twice) {
+  if (!enable()) return false;
+  if (!base_.sendExtCmd(addrOf(a), code)) return false;
+  if (twice && !base_.sendExtCmd(addrOf(a), code)) return false;
+  return true;
+}
+
+std::optional<int> DaliDT5::query(int a, int code) {
+  if (!enable()) return std::nullopt;
+  return base_.queryCmd(static_cast<uint8_t>(addrOf(a)), static_cast<uint8_t>(code));
+}
+
+bool DaliDT5::enableDT5() { return enable(); }
+
+bool DaliDT5::setOutputRange1To10V(int a) {
+  return send(a, DALI_CMD_DT5_SET_OUTPUT_RANGE_1_TO_10V, true);
+}
+
+bool DaliDT5::setOutputRange0To10V(int a) {
+  return send(a, DALI_CMD_DT5_SET_OUTPUT_RANGE_0_TO_10V, true);
+}
+
+bool DaliDT5::switchOnInternalPullUp(int a) {
+  return send(a, DALI_CMD_DT5_SWITCH_ON_INTERNAL_PULL_UP, true);
+}
+
+bool DaliDT5::switchOffInternalPullUp(int a) {
+  return send(a, DALI_CMD_DT5_SWITCH_OFF_INTERNAL_PULL_UP, true);
+}
+
+bool DaliDT5::storePhysicalMinimum(int a, int level) {
+  const int value = std::clamp(level, 0, 254);
+  return enable() && base_.setDTR(value) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT5_STORE_DTR_AS_PHYSICAL_MINIMUM) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT5_STORE_DTR_AS_PHYSICAL_MINIMUM);
+}
+
+bool DaliDT5::selectDimmingCurve(int a, int curve) {
+  const int value = std::clamp(curve, 0, 255);
+  return enable() && base_.setDTR(value) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT5_SELECT_DIMMING_CURVE) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT5_SELECT_DIMMING_CURVE);
+}
+
+bool DaliDT5::resetConverterSettings(int a) {
+  return send(a, DALI_CMD_DT5_RESET_CONVERTER_SETTINGS, true);
+}
+
+std::optional<int> DaliDT5::getDimmingCurve(int a) { return query(a, DALI_CMD_DT5_QUERY_DIMMING_CURVE); }
+
+std::optional<int> DaliDT5::getOutputLevelRaw(int a) {
+  return query(a, DALI_CMD_DT5_QUERY_OUTPUT_LEVEL);
+}
+
+std::optional<double> DaliDT5::getOutputLevelVolts(int a) {
+  const auto raw = getOutputLevelRaw(a);
+  if (!raw.has_value() || raw.value() == 0xFF) return std::nullopt;
+  return raw.value() * 0.04;
+}
+
+std::optional<DaliDT5ConverterFeatures> DaliDT5::getConverterFeatures(int a) {
+  const auto raw = query(a, DALI_CMD_DT5_QUERY_CONVERTER_FEATURES);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT5ConverterFeatures(raw.value());
+}
+
+std::optional<DaliDT5FailureStatus> DaliDT5::getFailureStatus(int a) {
+  const auto raw = query(a, DALI_CMD_DT5_QUERY_FAILURE_STATUS);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT5FailureStatus(raw.value());
+}
+
+std::optional<DaliDT5ConverterStatus> DaliDT5::getConverterStatus(int a) {
+  const auto raw = query(a, DALI_CMD_DT5_QUERY_CONVERTER_STATUS);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT5ConverterStatus(raw.value());
+}
+
+std::optional<int> DaliDT5::getExtendedVersion(int a) {
+  return query(a, DALI_CMD_DT5_QUERY_EXTENDED_VERSION);
+}
\ No newline at end of file
diff --git a/src/dt6.cpp b/src/dt6.cpp
new file mode 100644
index 0000000..df1f527
--- /dev/null
+++ b/src/dt6.cpp
@@ -0,0 +1,139 @@
+#include "dt6.hpp"
+
+#include "dali_define.hpp"
+
+#include <algorithm>
+
+DaliDT6::DaliDT6(DaliBase& base) : base_(base) {}
+
+bool DaliDT6::enable() { return base_.dtSelect(6); }
+
+int DaliDT6::addrOf(int a) { return a * 2 + 1; }
+
+bool DaliDT6::send(int a, int code, bool twice) {
+  if (!enable()) return false;
+  if (!base_.sendExtCmd(addrOf(a), code)) return false;
+  if (twice && !base_.sendExtCmd(addrOf(a), code)) return false;
+  return true;
+}
+
+std::optional<int> DaliDT6::query(int a, int code) {
+  if (!enable()) return std::nullopt;
+  return base_.queryCmd(static_cast<uint8_t>(addrOf(a)), static_cast<uint8_t>(code));
+}
+
+std::optional<bool> DaliDT6::queryYesNo(int a, int code) {
+  const auto value = query(a, code);
+  if (!value.has_value()) return std::nullopt;
+  return value.value() != 0;
+}
+
+bool DaliDT6::enableDT6() { return enable(); }
+
+bool DaliDT6::referenceSystemPower(int a) {
+  return send(a, DALI_CMD_DT6_REFERENCE_SYSTEM_POWER, true);
+}
+
+bool DaliDT6::enableCurrentProtector(int a) {
+  return send(a, DALI_CMD_DT6_ENABLE_CURRENT_PROTECTOR, true);
+}
+
+bool DaliDT6::disableCurrentProtector(int a) {
+  return send(a, DALI_CMD_DT6_DISABLE_CURRENT_PROTECTOR, true);
+}
+
+bool DaliDT6::selectDimmingCurve(int a, int curve) {
+  const int value = std::clamp(curve, 0, 255);
+  return enable() && base_.setDTR(value) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT6_SELECT_DIMMING_CURVE) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT6_SELECT_DIMMING_CURVE);
+}
+
+bool DaliDT6::storeFastFadeTime(int a, int value) {
+  const int clamped = std::clamp(value, 0, 27);
+  return enable() && base_.setDTR(clamped) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT6_STORE_DTR_AS_FAST_FADE_TIME) &&
+         base_.sendExtCmd(addrOf(a), DALI_CMD_DT6_STORE_DTR_AS_FAST_FADE_TIME);
+}
+
+std::optional<DaliDT6GearType> DaliDT6::getGearType(int a) {
+  const auto raw = query(a, DALI_CMD_DT6_QUERY_GEAR_TYPE);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT6GearType(raw.value());
+}
+
+std::optional<int> DaliDT6::getDimmingCurve(int a) { return query(a, DALI_CMD_DT6_QUERY_DIMMING_CURVE); }
+
+std::optional<DaliDT6OperatingModes> DaliDT6::getPossibleOperatingModes(int a) {
+  const auto raw = query(a, DALI_CMD_DT6_QUERY_POSSIBLE_OPERATING_MODES);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT6OperatingModes(raw.value());
+}
+
+std::optional<DaliDT6Features> DaliDT6::getFeatures(int a) {
+  const auto raw = query(a, DALI_CMD_DT6_QUERY_FEATURES);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT6Features(raw.value());
+}
+
+std::optional<DaliDT6FailureStatus> DaliDT6::getFailureStatus(int a) {
+  const auto raw = query(a, DALI_CMD_DT6_QUERY_FAILURE_STATUS);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT6FailureStatus(raw.value());
+}
+
+std::optional<bool> DaliDT6::hasShortCircuit(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_SHORT_CIRCUIT);
+}
+
+std::optional<bool> DaliDT6::hasOpenCircuit(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_OPEN_CIRCUIT);
+}
+
+std::optional<bool> DaliDT6::hasLoadDecrease(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_LOAD_DECREASE);
+}
+
+std::optional<bool> DaliDT6::hasLoadIncrease(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_LOAD_INCREASE);
+}
+
+std::optional<bool> DaliDT6::isCurrentProtectorActive(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_CURRENT_PROTECTOR_ACTIVE);
+}
+
+std::optional<bool> DaliDT6::hasThermalShutDown(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_THERMAL_SHUTDOWN);
+}
+
+std::optional<bool> DaliDT6::hasThermalOverload(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_THERMAL_OVERLOAD);
+}
+
+std::optional<bool> DaliDT6::isReferenceRunning(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_REFERENCE_RUNNING);
+}
+
+std::optional<bool> DaliDT6::isReferenceMeasurementFailed(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_REFERENCE_MEASUREMENT_FAILED);
+}
+
+std::optional<bool> DaliDT6::isCurrentProtectorEnabled(int a) {
+  return queryYesNo(a, DALI_CMD_DT6_QUERY_CURRENT_PROTECTOR_ENABLED);
+}
+
+std::optional<DaliDT6OperatingMode> DaliDT6::getOperatingMode(int a) {
+  const auto raw = query(a, DALI_CMD_DT6_QUERY_OPERATING_MODE);
+  if (!raw.has_value()) return std::nullopt;
+  return DaliDT6OperatingMode(raw.value());
+}
+
+std::optional<int> DaliDT6::getFastFadeTime(int a) { return query(a, DALI_CMD_DT6_QUERY_FAST_FADE_TIME); }
+
+std::optional<int> DaliDT6::getMinFastFadeTime(int a) {
+  return query(a, DALI_CMD_DT6_QUERY_MIN_FAST_FADE_TIME);
+}
+
+std::optional<int> DaliDT6::getExtendedVersion(int a) {
+  return query(a, DALI_CMD_DT6_QUERY_EXTENDED_VERSION);
+}
\ No newline at end of file