diff --git a/PlantBox.Shared/Communication/Commands/CaptorValue.cs b/PlantBox.Shared/Communication/Commands/CaptorValue.cs
index a760d66..7819177 100644
--- a/PlantBox.Shared/Communication/Commands/CaptorValue.cs
+++ b/PlantBox.Shared/Communication/Commands/CaptorValue.cs
@@ -13,6 +13,10 @@ namespace PlantBox.Shared.Communication.Commands
         public double Max { get; set; }
         public double Value { get; set; }
 
+        public CaptorValue()
+        {
+
+        }
         public CaptorValue(string argument)
         {
             string[] arguments = argument.Split(ValueSeparator);
diff --git a/PlantBox.Shared/Communication/Commands/HistoricResponse.cs b/PlantBox.Shared/Communication/Commands/HistoricResponse.cs
index b3bbcf3..d62b16f 100644
--- a/PlantBox.Shared/Communication/Commands/HistoricResponse.cs
+++ b/PlantBox.Shared/Communication/Commands/HistoricResponse.cs
@@ -58,7 +58,7 @@ namespace PlantBox.Shared.Communication.Commands
         {
             string Join(double[] values)
             {
-                return string.Join(ValueSeparator.ToString(), values);
+                return string.Join(ValueSeparator.ToString(), values.Select(x => x.ToArgument()));
             }
 
             return new[]