diff --git a/server/src/Hubs/DigitalTubesHub.cs b/server/src/Hubs/DigitalTubesHub.cs
index 30627ba..ab82713 100644
--- a/server/src/Hubs/DigitalTubesHub.cs
+++ b/server/src/Hubs/DigitalTubesHub.cs
@@ -100,7 +100,7 @@ public class DigitalTubesHub : Hub<IDigitalTubesReceiver>, IDigitalTubesHub
         return Task.Run(async () =>
         {
             var cntError = 0;
-            while (info.IsRunning && !info.CTS.IsCancellationRequested)
+            while (!info.CTS.IsCancellationRequested)
             {
                 var beginTime = DateTime.Now;
                 var waitTime = TimeSpan.FromMilliseconds(1000 / info.Frequency);
@@ -142,6 +142,11 @@ public class DigitalTubesHub : Hub<IDigitalTubesReceiver>, IDigitalTubesHub
                 if (!info.IsRunning)
                 {
                     info.IsRunning = true;
+                    if (info.CTS.IsCancellationRequested)
+                    {
+                        info.CTS.Dispose();
+                        info.CTS = new CancellationTokenSource();
+                    }
                     _ = ScanAllTubes(info);
                 }
             }
@@ -167,7 +172,8 @@ public class DigitalTubesHub : Hub<IDigitalTubesReceiver>, IDigitalTubesHub
                     new SevenDigitalTubesCtrl(board.IpAddr, board.Port, 2))
             ) is DigitalTubeInfo info)
             {
-                if (info.IsRunning) info.IsRunning = false;
+                info.IsRunning = false;
+                info.CTS.Cancel();
             }
 
             return Task.FromResult(true);
diff --git a/server/src/Peripherals/SevenDigitalTubesClient.cs b/server/src/Peripherals/SevenDigitalTubesClient.cs
index 4c1abc9..733e8a6 100644
--- a/server/src/Peripherals/SevenDigitalTubesClient.cs
+++ b/server/src/Peripherals/SevenDigitalTubesClient.cs
@@ -52,7 +52,7 @@ public class SevenDigitalTubesCtrl
         if (ret.Value.Options.Data == null || ret.Value.Options.Data.Length < 4)
             return new(new Exception("Data length is too short"));
 
-        var data = Number.BytesToUInt32(ret.Value.Options.Data, 0, 4, true).Value;
+        var data = Number.BytesToUInt32(ret.Value.Options.Data, 0, 4).Value;
 
         if ((data >> 8) != num)
         {