diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/Device.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/Device.kt
index 230872d..c64af12 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/Device.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/Device.kt
@@ -47,7 +47,7 @@ public interface Device : Closeable, ContextAware, CoroutineScope {
      * Set property [value] for a property with name [propertyName].
      * In rare cases could suspend if the [Device] supports command queue and it is full at the moment.
      */
-    public suspend fun writeItem(propertyName: String, value: Meta)
+    public suspend fun writeProperty(propertyName: String, value: Meta)
 
     /**
      * A subscription-based [Flow] of [DeviceMessage] provided by device. The flow is guaranteed to be readable
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/DeviceHub.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/DeviceHub.kt
index 16d5970..aba8517 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/DeviceHub.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/api/DeviceHub.kt
@@ -59,8 +59,8 @@ public operator fun DeviceHub.get(nameString: String): Device =
 public suspend fun DeviceHub.readProperty(deviceName: Name, propertyName: String): Meta =
     this[deviceName].readProperty(propertyName)
 
-public suspend fun DeviceHub.writeItem(deviceName: Name, propertyName: String, value: Meta) {
-    this[deviceName].writeItem(propertyName, value)
+public suspend fun DeviceHub.writeProperty(deviceName: Name, propertyName: String, value: Meta) {
+    this[deviceName].writeProperty(propertyName, value)
 }
 
 public suspend fun DeviceHub.execute(deviceName: Name, command: String, argument: Meta?): Meta? =
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/base/DeviceBase.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/base/DeviceBase.kt
index 7b4d59c..52d37bf 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/base/DeviceBase.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/base/DeviceBase.kt
@@ -164,7 +164,7 @@ public abstract class DeviceBase(final override val context: Context) : Device {
         (_properties[propertyName] ?: error("Property with name $propertyName not defined")).invalidate()
     }
 
-    override suspend fun writeItem(propertyName: String, value: Meta) {
+    override suspend fun writeProperty(propertyName: String, value: Meta) {
         (_properties[propertyName] as? DeviceProperty ?: error("Property with name $propertyName not defined")).write(
             value
         )
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/controllers/deviceMessages.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/controllers/deviceMessages.kt
index bd71182..75781e6 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/controllers/deviceMessages.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/controllers/deviceMessages.kt
@@ -25,7 +25,7 @@ public suspend fun Device.respondMessage(deviceTarget: Name, request: DeviceMess
             if (request.value == null) {
                 invalidate(request.property)
             } else {
-                writeItem(request.property, request.value)
+                writeProperty(request.property, request.value)
             }
             PropertyChangedMessage(
                 property = request.property,
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceBySpec.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceBySpec.kt
index 91f0d61..2d8ce2a 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceBySpec.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceBySpec.kt
@@ -11,11 +11,7 @@ import ru.mipt.npm.controls.api.*
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.meta.Meta
-import space.kscience.dataforge.meta.transformations.MetaConverter
 import kotlin.coroutines.CoroutineContext
-import kotlin.properties.Delegates.observable
-import kotlin.properties.ReadWriteProperty
-import kotlin.reflect.KProperty
 
 /**
  * A device generated from specification
@@ -58,7 +54,7 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
 
     private val stateLock = Mutex()
 
-    private suspend fun updateLogical(propertyName: String, value: Meta?) {
+    protected suspend fun updateLogical(propertyName: String, value: Meta?) {
         if (value != logicalState[propertyName]) {
             stateLock.withLock {
                 logicalState[propertyName] = value
@@ -74,7 +70,7 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
      * The logical state is updated after read
      */
     override suspend fun readProperty(propertyName: String): Meta {
-        val newValue = properties[propertyName]?.readItem(self)
+        val newValue = properties[propertyName]?.readMeta(self)
             ?: error("A property with name $propertyName is not registered in $this")
         updateLogical(propertyName, newValue)
         return newValue
@@ -88,10 +84,10 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
         }
     }
 
-    override suspend fun writeItem(propertyName: String, value: Meta): Unit {
+    override suspend fun writeProperty(propertyName: String, value: Meta): Unit {
         //If there is a physical property with given name, invalidate logical property and write physical one
-        (properties[propertyName] as? WritableDevicePropertySpec<D, out Any>)?.let {
-            it.writeItem(self, value)
+        (properties[propertyName] as? WritableDevicePropertySpec<D, out Any?>)?.let {
+            it.writeMeta(self, value)
             invalidate(propertyName)
         } ?: run {
             updateLogical(propertyName, value)
@@ -99,39 +95,23 @@ public open class DeviceBySpec<D : DeviceBySpec<D>>(
     }
 
     override suspend fun execute(action: String, argument: Meta?): Meta? =
-        actions[action]?.executeItem(self, argument)
-
-
-    /**
-     * A delegate that represents the logical-only state of the device
-     */
-    public fun <T : Any> state(
-        converter: MetaConverter<T>,
-        initialValue: T,
-    ): ReadWriteProperty<D, T> = observable(initialValue) { property: KProperty<*>, oldValue: T, newValue: T ->
-        if (oldValue != newValue) {
-            launch {
-                invalidate(property.name)
-                sharedMessageFlow.emit(PropertyChangedMessage(property.name, converter.objectToMeta(newValue)))
-            }
-        }
-    }
+        actions[action]?.executeMeta(self, argument)
 
     /**
      * Read typed value and update/push event if needed
      */
-    public suspend fun <T : Any> DevicePropertySpec<D, T>.read(): T {
+    public suspend fun <T> DevicePropertySpec<D, T>.read(): T {
         val res = read(self)
         updateLogical(name, converter.objectToMeta(res))
         return res
     }
 
-    public fun <T : Any> DevicePropertySpec<D, T>.get(): T? = getProperty(name)?.let(converter::metaToObject)
+    public fun <T> DevicePropertySpec<D, T>.get(): T? = getProperty(name)?.let(converter::metaToObject)
 
     /**
      * Write typed property state and invalidate logical state
      */
-    public suspend fun <T : Any> WritableDevicePropertySpec<D, T>.write(value: T) {
+    public suspend fun <T> WritableDevicePropertySpec<D, T>.write(value: T) {
         write(self, value)
         invalidate(name)
     }
@@ -146,7 +126,7 @@ public suspend fun <D : DeviceBySpec<D>, T : Any> D.read(
     propertySpec: DevicePropertySpec<D, T>
 ): T = propertySpec.read()
 
-public fun <D : DeviceBySpec<D>, T : Any> D.write(
+public fun <D : DeviceBySpec<D>, T> D.write(
     propertySpec: WritableDevicePropertySpec<D, T>,
     value: T
 ): Job = launch {
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DevicePropertySpec.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DevicePropertySpec.kt
index 5184d1d..23ceffb 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DevicePropertySpec.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DevicePropertySpec.kt
@@ -5,8 +5,6 @@ import ru.mipt.npm.controls.api.Device
 import ru.mipt.npm.controls.api.PropertyDescriptor
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.transformations.MetaConverter
-import space.kscience.dataforge.meta.transformations.nullableMetaToObject
-import space.kscience.dataforge.meta.transformations.nullableObjectToMeta
 
 
 /**
@@ -15,8 +13,7 @@ import space.kscience.dataforge.meta.transformations.nullableObjectToMeta
 @RequiresOptIn
 public annotation class InternalDeviceAPI
 
-//TODO relax T restriction after DF 0.4.4
-public interface DevicePropertySpec<in D : Device, T : Any> {
+public interface DevicePropertySpec<in D : Device, T> {
     /**
      * Property name, should be unique in device
      */
@@ -40,11 +37,11 @@ public interface DevicePropertySpec<in D : Device, T : Any> {
 }
 
 @OptIn(InternalDeviceAPI::class)
-public suspend fun <D : Device, T : Any> DevicePropertySpec<D, T>.readItem(device: D): Meta =
+public suspend fun <D : Device, T> DevicePropertySpec<D, T>.readMeta(device: D): Meta =
     converter.objectToMeta(read(device))
 
 
-public interface WritableDevicePropertySpec<in D : Device, T : Any> : DevicePropertySpec<D, T> {
+public interface WritableDevicePropertySpec<in D : Device, T> : DevicePropertySpec<D, T> {
     /**
      * Write physical value to a device
      */
@@ -53,11 +50,11 @@ public interface WritableDevicePropertySpec<in D : Device, T : Any> : DeviceProp
 }
 
 @OptIn(InternalDeviceAPI::class)
-public suspend fun <D : Device, T : Any> WritableDevicePropertySpec<D, T>.writeItem(device: D, item: Meta) {
+public suspend fun <D : Device, T> WritableDevicePropertySpec<D, T>.writeMeta(device: D, item: Meta) {
     write(device, converter.metaToObject(item) ?: error("Meta $item could not be read with $converter"))
 }
 
-public interface DeviceActionSpec<in D : Device, I : Any, O : Any> {
+public interface DeviceActionSpec<in D : Device, I, O> {
     /**
      * Action name, should be unique in device
      */
@@ -78,11 +75,11 @@ public interface DeviceActionSpec<in D : Device, I : Any, O : Any> {
     public suspend fun execute(device: D, input: I?): O?
 }
 
-public suspend fun <D : Device, I : Any, O : Any> DeviceActionSpec<D, I, O>.executeItem(
+public suspend fun <D : Device, I, O> DeviceActionSpec<D, I, O>.executeMeta(
     device: D,
     item: Meta?
 ): Meta? {
-    val arg = inputConverter.nullableMetaToObject(item)
+    val arg = item?.let { inputConverter.metaToObject(item) }
     val res = execute(device, arg)
-    return outputConverter.nullableObjectToMeta(res)
+    return res?.let { outputConverter.objectToMeta(res) }
 }
\ No newline at end of file
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceSpec.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceSpec.kt
index 17d52c7..35e59ba 100644
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceSpec.kt
+++ b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/DeviceSpec.kt
@@ -52,8 +52,9 @@ public abstract class DeviceSpec<D : DeviceBySpec<D>>(
             override val name: String = readWriteProperty.name
             override val descriptor: PropertyDescriptor = PropertyDescriptor(this.name).apply(descriptorBuilder)
             override val converter: MetaConverter<T> = converter
-            override suspend fun read(device: D): T =
-                withContext(device.coroutineContext) { readWriteProperty.get(device) }
+            override suspend fun read(device: D): T = withContext(device.coroutineContext) {
+                readWriteProperty.get(device)
+            }
 
             override suspend fun write(device: D, value: T) = withContext(device.coroutineContext) {
                 readWriteProperty.set(device, value)
@@ -145,12 +146,12 @@ public abstract class DeviceSpec<D : DeviceBySpec<D>>(
     /**
      * The function is executed right after device initialization is finished
      */
-    public open fun D.onStartup(){}
+    public open fun D.onStartup() {}
 
     /**
      * The function is executed before device is shut down
      */
-    public open fun D.onShutdown(){}
+    public open fun D.onShutdown() {}
 
 
     override fun invoke(meta: Meta, context: Context): D = buildDevice().apply {
diff --git a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/deviceStateDelegates.kt b/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/deviceStateDelegates.kt
deleted file mode 100644
index f3f4c69..0000000
--- a/controls-core/src/commonMain/kotlin/ru/mipt/npm/controls/properties/deviceStateDelegates.kt
+++ /dev/null
@@ -1,12 +0,0 @@
-package ru.mipt.npm.controls.properties
-
-import space.kscience.dataforge.meta.transformations.MetaConverter
-import kotlin.properties.ReadWriteProperty
-
-public fun <D : DeviceBySpec<D>> D.state(
-    initialValue: Double,
-): ReadWriteProperty<D, Double> = state(MetaConverter.double, initialValue)
-
-public fun <D : DeviceBySpec<D>> D.state(
-    initialValue: Number,
-): ReadWriteProperty<D, Number> = state(MetaConverter.number, initialValue)
\ No newline at end of file
diff --git a/controls-magix-client/src/commonMain/kotlin/ru/mipt/npm/controls/client/tangoMagix.kt b/controls-magix-client/src/commonMain/kotlin/ru/mipt/npm/controls/client/tangoMagix.kt
index e04a7ed..239089b 100644
--- a/controls-magix-client/src/commonMain/kotlin/ru/mipt/npm/controls/client/tangoMagix.kt
+++ b/controls-magix-client/src/commonMain/kotlin/ru/mipt/npm/controls/client/tangoMagix.kt
@@ -94,7 +94,7 @@ public fun DeviceManager.launchTangoMagix(
                     }
                     TangoAction.write -> {
                         request.payload.value?.let { value ->
-                            device.writeItem(request.payload.name, value)
+                            device.writeProperty(request.payload.name, value)
                         }
                         //wait for value to be written and return final state
                         val value = device.getOrReadItem(request.payload.name)
diff --git a/controls-opcua/build.gradle.kts b/controls-opcua/build.gradle.kts
index caea7f5..c3874f2 100644
--- a/controls-opcua/build.gradle.kts
+++ b/controls-opcua/build.gradle.kts
@@ -8,6 +8,7 @@ val miloVersion: String = "0.6.3"
 
 dependencies {
     api(project(":controls-core"))
+    api("org.jetbrains.kotlinx:kotlinx-coroutines-jdk8:${ru.mipt.npm.gradle.KScienceVersions.coroutinesVersion}")
     implementation("org.eclipse.milo:sdk-client:$miloVersion")
     implementation("org.eclipse.milo:bsd-parser:$miloVersion")
     implementation("org.eclipse.milo:dictionary-reader:$miloVersion")
diff --git a/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDevice.kt b/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDevice.kt
index ae79425..7ea36de 100644
--- a/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDevice.kt
+++ b/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDevice.kt
@@ -1,16 +1,12 @@
 package ru.mipt.npm.controls.opcua
 
+import kotlinx.coroutines.future.await
 import org.eclipse.milo.opcua.sdk.client.OpcUaClient
-import org.eclipse.milo.opcua.stack.core.types.builtin.DataValue
-import org.eclipse.milo.opcua.stack.core.types.builtin.ExtensionObject
-import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId
-import org.eclipse.milo.opcua.stack.core.types.builtin.Variant
+import org.eclipse.milo.opcua.stack.core.types.builtin.*
 import org.eclipse.milo.opcua.stack.core.types.enumerated.TimestampsToReturn
 import ru.mipt.npm.controls.api.Device
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.transformations.MetaConverter
-import kotlin.properties.ReadWriteProperty
-import kotlin.reflect.KProperty
 
 
 /**
@@ -28,40 +24,46 @@ public interface MiloDevice : Device {
     }
 }
 
-public inline fun <reified T> MiloDevice.opc(
+public suspend inline fun <reified T> MiloDevice.readOpcWithTime(
     nodeId: NodeId,
     converter: MetaConverter<T>,
     magAge: Double = 500.0
-): ReadWriteProperty<Any?, T> = object : ReadWriteProperty<Any?, T> {
-    override fun getValue(thisRef: Any?, property: KProperty<*>): T {
-        val data = client.readValue(magAge, TimestampsToReturn.Server, nodeId).get()
-        val meta: Meta = when (val content = data.value.value) {
-            is T -> return content
-            content is Meta -> content as Meta
-            content is ExtensionObject -> (content as ExtensionObject).decode(client.dynamicSerializationContext) as Meta
-            else -> error("Incompatible OPC property value $content")
-        }
-
-        return converter.metaToObject(meta) ?: error("Meta $meta could not be converted to ${T::class}")
+): Pair<T, DateTime> {
+    val data = client.readValue(magAge, TimestampsToReturn.Server, nodeId).await()
+    val time = data.serverTime ?: error("No server time provided")
+    val meta: Meta = when (val content = data.value.value) {
+        is T -> return content to time
+        content is Meta -> content as Meta
+        content is ExtensionObject -> (content as ExtensionObject).decode(client.dynamicSerializationContext) as Meta
+        else -> error("Incompatible OPC property value $content")
     }
 
-    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
-        val meta = converter.objectToMeta(value)
-        client.writeValue(nodeId, DataValue(Variant(meta)))
-    }
+    val res = converter.metaToObject(meta) ?: error("Meta $meta could not be converted to ${T::class}")
+    return res to time
 }
 
-public inline fun <reified T> MiloDevice.opcDouble(
+public suspend inline fun <reified T> MiloDevice.readOpc(
     nodeId: NodeId,
-    magAge: Double = 1.0
-): ReadWriteProperty<Any?, Double> = opc(nodeId, MetaConverter.double, magAge)
+    converter: MetaConverter<T>,
+    magAge: Double = 500.0
+): T {
+    val data = client.readValue(magAge, TimestampsToReturn.Neither, nodeId).await()
 
-public inline fun <reified T> MiloDevice.opcInt(
-    nodeId: NodeId,
-    magAge: Double = 1.0
-): ReadWriteProperty<Any?, Int> = opc(nodeId, MetaConverter.int, magAge)
+    val meta: Meta = when (val content = data.value.value) {
+        is T -> return content
+        content is Meta -> content as Meta
+        content is ExtensionObject -> (content as ExtensionObject).decode(client.dynamicSerializationContext) as Meta
+        else -> error("Incompatible OPC property value $content")
+    }
 
-public inline fun <reified T> MiloDevice.opcString(
+    return converter.metaToObject(meta) ?: error("Meta $meta could not be converted to ${T::class}")
+}
+
+public suspend inline fun <reified T> MiloDevice.writeOpc(
     nodeId: NodeId,
-    magAge: Double = 1.0
-): ReadWriteProperty<Any?, String> = opc(nodeId, MetaConverter.string, magAge)
\ No newline at end of file
+    converter: MetaConverter<T>,
+    value: T
+): StatusCode {
+    val meta = converter.objectToMeta(value)
+    return client.writeValue(nodeId, DataValue(Variant(meta))).await()
+}
\ No newline at end of file
diff --git a/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDeviceBySpec.kt b/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDeviceBySpec.kt
index 6b98de2..b60498e 100644
--- a/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDeviceBySpec.kt
+++ b/controls-opcua/src/main/kotlin/ru/mipt/npm/controls/opcua/MiloDeviceBySpec.kt
@@ -1,6 +1,9 @@
 package ru.mipt.npm.controls.opcua
 
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 import org.eclipse.milo.opcua.sdk.client.OpcUaClient
+import org.eclipse.milo.opcua.stack.core.types.builtin.NodeId
 import ru.mipt.npm.controls.properties.DeviceBySpec
 import ru.mipt.npm.controls.properties.DeviceSpec
 import space.kscience.dataforge.context.Context
@@ -8,12 +11,15 @@ import space.kscience.dataforge.context.Global
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.get
 import space.kscience.dataforge.meta.string
+import space.kscience.dataforge.meta.transformations.MetaConverter
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
 
-public open class MiloDeviceBySpec<D: MiloDeviceBySpec<D>>(
+public open class MiloDeviceBySpec<D : MiloDeviceBySpec<D>>(
     spec: DeviceSpec<D>,
     context: Context = Global,
     meta: Meta = Meta.EMPTY
-): MiloDevice, DeviceBySpec<D>(spec, context, meta) {
+) : MiloDevice, DeviceBySpec<D>(spec, context, meta) {
 
     override val client: OpcUaClient by lazy {
         val endpointUrl = meta["endpointUrl"].string ?: error("Endpoint url is not defined")
@@ -26,4 +32,38 @@ public open class MiloDeviceBySpec<D: MiloDeviceBySpec<D>>(
         super<MiloDevice>.close()
         super<DeviceBySpec>.close()
     }
-}
\ No newline at end of file
+}
+
+/**
+ * A device-bound OPC-UA property. Does not trigger device properties change.
+ */
+public inline fun <reified T> MiloDeviceBySpec<*>.opc(
+    nodeId: NodeId,
+    converter: MetaConverter<T>,
+    magAge: Double = 500.0
+): ReadWriteProperty<Any?, T> = object : ReadWriteProperty<Any?, T> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): T = runBlocking {
+        readOpc(nodeId, converter, magAge)
+    }
+
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
+        launch {
+            writeOpc(nodeId, converter, value)
+        }
+    }
+}
+
+public inline fun <reified T> MiloDeviceBySpec<*>.opcDouble(
+    nodeId: NodeId,
+    magAge: Double = 1.0
+): ReadWriteProperty<Any?, Double> = opc(nodeId, MetaConverter.double, magAge)
+
+public inline fun <reified T> MiloDeviceBySpec<*>.opcInt(
+    nodeId: NodeId,
+    magAge: Double = 1.0
+): ReadWriteProperty<Any?, Int> = opc(nodeId, MetaConverter.int, magAge)
+
+public inline fun <reified T> MiloDeviceBySpec<*>.opcString(
+    nodeId: NodeId,
+    magAge: Double = 1.0
+): ReadWriteProperty<Any?, String> = opc(nodeId, MetaConverter.string, magAge)
\ No newline at end of file
diff --git a/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoControllerView.kt b/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoControllerView.kt
index 4ef7d4a..4f61194 100644
--- a/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoControllerView.kt
+++ b/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoControllerView.kt
@@ -10,6 +10,9 @@ import ru.mipt.npm.controls.api.DeviceMessage
 import ru.mipt.npm.controls.client.connectToMagix
 import ru.mipt.npm.controls.controllers.DeviceManager
 import ru.mipt.npm.controls.controllers.install
+import ru.mipt.npm.controls.demo.DemoDevice.Companion.cosScale
+import ru.mipt.npm.controls.demo.DemoDevice.Companion.sinScale
+import ru.mipt.npm.controls.demo.DemoDevice.Companion.timeScale
 import ru.mipt.npm.magix.api.MagixEndpoint
 import ru.mipt.npm.magix.rsocket.rSocketWithTcp
 import ru.mipt.npm.magix.rsocket.rSocketWithWebSockets
@@ -97,10 +100,12 @@ class DemoControllerView : View(title = " Demo controller remote") {
         button("Submit") {
             useMaxWidth = true
             action {
-                controller.device?.apply {
-                    timeScale = timeScaleSlider.value
-                    sinScale = xScaleSlider.value
-                    cosScale = yScaleSlider.value
+                controller.device?.run {
+                    launch {
+                        timeScale.write(timeScaleSlider.value)
+                        sinScale.write(xScaleSlider.value)
+                        cosScale.write(yScaleSlider.value)
+                    }
                 }
             }
         }
diff --git a/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoDevice.kt b/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoDevice.kt
index 308bc48..8d88199 100644
--- a/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoDevice.kt
+++ b/demo/src/main/kotlin/ru/mipt/npm/controls/demo/DemoDevice.kt
@@ -9,24 +9,24 @@ import kotlin.time.ExperimentalTime
 
 
 class DemoDevice : DeviceBySpec<DemoDevice>(DemoDevice) {
-    var timeScale by state(5000.0)
-    var sinScale by state(1.0)
-    var cosScale by state(1.0)
+    private var timeScaleState = 5000.0
+    private var sinScaleState = 1.0
+    private var cosScaleState = 1.0
 
     companion object : DeviceSpec<DemoDevice>(::DemoDevice) {
         // register virtual properties based on actual object state
-        val timeScaleProperty = registerProperty(MetaConverter.double, DemoDevice::timeScale)
-        val sinScaleProperty = registerProperty(MetaConverter.double, DemoDevice::sinScale)
-        val cosScaleProperty = registerProperty(MetaConverter.double, DemoDevice::cosScale)
+        val timeScale = registerProperty(MetaConverter.double, DemoDevice::timeScaleState)
+        val sinScale = registerProperty(MetaConverter.double, DemoDevice::sinScaleState)
+        val cosScale = registerProperty(MetaConverter.double, DemoDevice::cosScaleState)
 
         val sin by doubleProperty {
             val time = Instant.now()
-            kotlin.math.sin(time.toEpochMilli().toDouble() / timeScale) * sinScale
+            kotlin.math.sin(time.toEpochMilli().toDouble() / timeScaleState) * sinScaleState
         }
 
         val cos by doubleProperty {
             val time = Instant.now()
-            kotlin.math.cos(time.toEpochMilli().toDouble() / timeScale) * sinScale
+            kotlin.math.cos(time.toEpochMilli().toDouble() / timeScaleState) * sinScaleState
         }
 
         val coordinates by metaProperty {
@@ -39,9 +39,9 @@ class DemoDevice : DeviceBySpec<DemoDevice>(DemoDevice) {
         }
 
         val resetScale by action(MetaConverter.meta, MetaConverter.meta) {
-            timeScale = 5000.0
-            sinScale = 1.0
-            cosScale = 1.0
+            timeScale.write(5000.0)
+            sinScale.write(1.0)
+            cosScale.write(1.0)
             null
         }