diff --git a/TBF/Properties/AssemblyInfo.cs b/TBF/Properties/AssemblyInfo.cs
index 8bdd46065..438946eaa 100644
--- a/TBF/Properties/AssemblyInfo.cs
+++ b/TBF/Properties/AssemblyInfo.cs
@@ -32,5 +32,5 @@ using System.Runtime.InteropServices;
 //      Build Number
 //      Revision
 //
-[assembly: AssemblyVersion("3.9.3066.1")]
-[assembly: AssemblyFileVersion("3.9.3066.1")]
+[assembly: AssemblyVersion("3.9.3067.1")]
+[assembly: AssemblyFileVersion("3.9.3067.1")]
diff --git a/TBF/Rig/TestMethods/iPerlCommunication/iPerlHead/IperlHead.cs b/TBF/Rig/TestMethods/iPerlCommunication/iPerlHead/IperlHead.cs
index 9fe5b1d29..502c11afd 100644
--- a/TBF/Rig/TestMethods/iPerlCommunication/iPerlHead/IperlHead.cs
+++ b/TBF/Rig/TestMethods/iPerlCommunication/iPerlHead/IperlHead.cs
@@ -46,9 +46,12 @@ namespace TBF.Rig.TestMethods.iPerlCommunication.iPerlHead
         public const string OptoDataDirectory = "C:\\TBF\\ProcessData";
         public const int StartOptoDataCount = OptoDataBufferSize / 2;
         public const int EndOptoDataCount = OptoDataBufferSize - StartOptoDataCount;
-        public const int StartEndFilterSamplesCount2 = 2; //20      /// StartEndFilterSamplesCount = 2 * StartEndFilterSamplesCount2 + 1
+        public const int StartEndFilterSamplesCount2 = 1;  //20      /// StartEndFilterSamplesCount = 2 * StartEndFilterSamplesCount2 + 1
         public const int FeatureVectorSize = 9;
         
+        private const int StartSampleDelaySec = 5;
+        private const int EndSampleDelayCount = 2; 
+        
         private OptoHeadTest _optoHeadTest;
         
         public OptoHeadTest OptoHeadTest
@@ -385,9 +388,7 @@ namespace TBF.Rig.TestMethods.iPerlCommunication.iPerlHead
         ///
         public int TestStartTelegramIx;
         public int TestEndTelegramIx;
-        int endTelegramIdx1;
-        int endTelegramIdx2;
-        int endTelegramIdx3;
+        readonly int[] endTelegramIdx = new int[EndSampleDelayCount];
 
         int currentTelegramIx;
         bool startSampleAcquired;
@@ -670,19 +671,21 @@ namespace TBF.Rig.TestMethods.iPerlCommunication.iPerlHead
                 timeFromStart += StateMachine.Period;
                 ReadPulses();
 
-                if (!startSampleAcquired && (timeFromStart >= 8) && (currentTelegramIx >= 0))
+                if (!startSampleAcquired && (timeFromStart >= StartSampleDelaySec) && (currentTelegramIx >= 0))
                 {
-                    /// Take the test start sample
                     startSampleAcquired = true;
                     TestStartTelegramIx = currentTelegramIx;
                 }
                 else if (startSampleAcquired)
                 {
-                    /// Shift data in pipelines
-                    TestEndTelegramIx = endTelegramIdx3;
-                    endTelegramIdx3 = endTelegramIdx2;
-                    endTelegramIdx2 = endTelegramIdx1;
-                    endTelegramIdx1 = currentTelegramIx;
+                    TestEndTelegramIx = endTelegramIdx[EndSampleDelayCount - 1];
+
+                    for (int i = EndSampleDelayCount - 1; i > 0; i--)
+                    {
+                        endTelegramIdx[i] = endTelegramIdx[i - 1];
+                    }
+
+                    endTelegramIdx[0] = currentTelegramIx;
                 }
             }
 
@@ -983,9 +986,10 @@ namespace TBF.Rig.TestMethods.iPerlCommunication.iPerlHead
             currentTelegramIx = -1;
             startSampleAcquired = false;
             TestStartTelegramIx = 0;
-            endTelegramIdx1 = 0;
-            endTelegramIdx2 = 0;
-            endTelegramIdx3 = 0;
+            for (int i = 0; i < endTelegramIdx.Length; i++)
+            {
+                endTelegramIdx[i] = 0;
+            }
             TestEndTelegramIx = 0;
 
             if (optoSerialPort != null && optoSerialPort.IsOpen) optoSerialPort.DiscardInBuffer();