diff --git a/numass-core/src/main/kotlin/inr/numass/data/NumassDataUtils.kt b/numass-core/src/main/kotlin/inr/numass/data/NumassDataUtils.kt
index 505c3315..be21e448 100644
--- a/numass-core/src/main/kotlin/inr/numass/data/NumassDataUtils.kt
+++ b/numass-core/src/main/kotlin/inr/numass/data/NumassDataUtils.kt
@@ -3,9 +3,11 @@ package inr.numass.data
 import hep.dataforge.io.envelopes.Envelope
 import hep.dataforge.meta.Meta
 import hep.dataforge.meta.MetaBuilder
+import inr.numass.data.api.NumassBlock
 import inr.numass.data.api.NumassPoint
 import inr.numass.data.api.NumassSet
 import inr.numass.data.api.SimpleNumassPoint
+import inr.numass.data.storage.ProtoBlock
 import java.io.InputStream
 import java.util.stream.Collectors
 import java.util.stream.Stream
@@ -43,9 +45,16 @@ object NumassDataUtils {
 /**
  * Get valid data stream utilizing compression if it is present
  */
-val Envelope.dataStream : InputStream
-    get() = if(this.meta.getString("compression", "none") == "zlib"){
+val Envelope.dataStream: InputStream
+    get() = if (this.meta.getString("compression", "none") == "zlib") {
         ZipInputStream(this.data.stream)
     } else {
         this.data.stream
     }
+
+val NumassBlock.channel: Int
+    get() = if (this is ProtoBlock) {
+        this.channel
+    } else {
+        0
+    }
diff --git a/numass-core/src/main/kotlin/inr/numass/data/storage/ProtoNumassPoint.kt b/numass-core/src/main/kotlin/inr/numass/data/storage/ProtoNumassPoint.kt
index 2990db7b..c98c4b78 100644
--- a/numass-core/src/main/kotlin/inr/numass/data/storage/ProtoNumassPoint.kt
+++ b/numass-core/src/main/kotlin/inr/numass/data/storage/ProtoNumassPoint.kt
@@ -43,36 +43,6 @@ class ProtoNumassPoint(private val envelope: Envelope) : NumassPoint {
         return envelope.meta
     }
 
-    class ProtoBlock(val channel: Int, private val block: NumassProto.Point.Channel.Block, private val meta: Meta) : NumassBlock {
-
-        override fun getStartTime(): Instant {
-            return ofEpochNanos(block.time)
-        }
-
-        override fun getLength(): Duration {
-            return Duration.ofNanos((meta.getDouble("params.b_size") / meta.getDouble("params.sample_freq") * 1e9).toLong())
-        }
-
-        override fun getEvents(): Stream<NumassEvent> {
-            val blockTime = startTime
-            if (block.hasEvents()) {
-                val events = block.events
-                return IntStream.range(0, events.timesCount).mapToObj { i -> NumassEvent(events.getAmplitudes(i).toShort(), blockTime, events.getTimes(i)) }
-            } else {
-                return Stream.empty()
-            }
-        }
-
-        override fun getFrames(): Stream<NumassFrame> {
-            val tickSize = Duration.ofNanos((1e9 / meta.getInt("params.sample_freq")).toLong())
-            return block.framesList.stream().map { frame ->
-                val time = startTime.plusNanos(frame.time)
-                val data = frame.data.asReadOnlyByteBuffer()
-                NumassFrame(time, tickSize, data.asShortBuffer())
-            }
-        }
-    }
-
     companion object {
         fun readFile(path: Path): ProtoNumassPoint {
             return ProtoNumassPoint(NumassFileEnvelope.open(path, true))
@@ -85,3 +55,33 @@ class ProtoNumassPoint(private val envelope: Envelope) : NumassPoint {
         }
     }
 }
+
+class ProtoBlock(val channel: Int, private val block: NumassProto.Point.Channel.Block, private val meta: Meta) : NumassBlock {
+
+    override fun getStartTime(): Instant {
+        return ProtoNumassPoint.ofEpochNanos(block.time)
+    }
+
+    override fun getLength(): Duration {
+        return Duration.ofNanos((meta.getDouble("params.b_size") / meta.getDouble("params.sample_freq") * 1e9).toLong())
+    }
+
+    override fun getEvents(): Stream<NumassEvent> {
+        val blockTime = startTime
+        if (block.hasEvents()) {
+            val events = block.events
+            return IntStream.range(0, events.timesCount).mapToObj { i -> NumassEvent(events.getAmplitudes(i).toShort(), blockTime, events.getTimes(i)) }
+        } else {
+            return Stream.empty()
+        }
+    }
+
+    override fun getFrames(): Stream<NumassFrame> {
+        val tickSize = Duration.ofNanos((1e9 / meta.getInt("params.sample_freq")).toLong())
+        return block.framesList.stream().map { frame ->
+            val time = startTime.plusNanos(frame.time)
+            val data = frame.data.asReadOnlyByteBuffer()
+            NumassFrame(time, tickSize, data.asShortBuffer())
+        }
+    }
+}
\ No newline at end of file
diff --git a/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt b/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt
index f168ff12..0fce05e5 100644
--- a/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt
+++ b/numass-viewer/src/main/kotlin/inr/numass/viewer/AmplitudeView.kt
@@ -55,7 +55,7 @@ class AmplitudeView(
 
 
     private val container = PlotContainer(frame).apply {
-        val binnintSelector: ChoiceBox<Int> = ChoiceBox(FXCollections.observableArrayList(1, 2, 5, 10, 20, 50)).apply {
+        val binningSelector: ChoiceBox<Int> = ChoiceBox(FXCollections.observableArrayList(1, 2, 5, 10, 20, 50)).apply {
             minWidth = 0.0
             selectionModel.selectLast()
             binningProperty.bind(this.selectionModel.selectedItemProperty())
@@ -64,7 +64,7 @@ class AmplitudeView(
             minWidth = 0.0
             this.selectedProperty().bindBidirectional(normalizeProperty)
         }
-        addToSideBar(0, binnintSelector, normalizeSwitch)
+        addToSideBar(0, binningSelector, normalizeSwitch)
     }
 
     private val data: ObservableMap<String, NumassPoint> = FXCollections.observableHashMap()