diff -r 8d1cc99a8f54 -r 095c73591b7e controls/DebugVariablePanel/DebugVariableItem.py
--- a/controls/DebugVariablePanel/DebugVariableItem.py	Fri Jun 11 11:56:07 2021 +0200
+++ b/controls/DebugVariablePanel/DebugVariableItem.py	Mon Jun 14 16:48:39 2021 +0200
@@ -26,8 +26,9 @@
 from __future__ import absolute_import
 from datetime import timedelta
 import binascii
-import numpy
+import numpy as np
 from graphics.DebugDataConsumer import DebugDataConsumer, TYPE_TRANSLATOR
+from controls.DebugVariablePanel.RingBuffer import RingBuffer
 
 # -------------------------------------------------------------------------------
 #                 Constant for calculate CRC for string variables
@@ -142,8 +143,8 @@
         @return: Data as numpy.array([(tick, value, forced),...])
         """
         # Return immediately if data empty or none
-        if self.Data is None or len(self.Data) == 0:
-            return self.Data
+        if self.Data is None or self.Data.count == 0:
+            return None
 
         # Find nearest data outside given range indexes
         start_idx = (self.GetNearestData(start_tick, -1)
@@ -154,7 +155,7 @@
                    else len(self.Data))
 
         # Return data between indexes
-        return self.Data[start_idx:end_idx]
+        return self.Data.view[start_idx:end_idx]
 
     def GetRawValue(self, index):
         """
@@ -195,8 +196,8 @@
         if len(values) > 0:
             # Return value range for data in given tick range
             return (data,
-                    data[numpy.argmin(values), 1],
-                    data[numpy.argmax(values), 1])
+                    data[np.argmin(values), 1],
+                    data[np.argmax(values), 1])
 
         # Return default values
         return data, None, None
@@ -207,7 +208,7 @@
         """
         if self.StoreData and self.IsNumVariable():
             # Init table storing data
-            self.Data = numpy.array([]).reshape(0, 3)
+            self.Data = RingBuffer(3)
 
             # Init table storing raw data if variable is strin
             self.RawData = ([]
@@ -294,7 +295,7 @@
                     [float(tick), num_value, extra_value])
 
             # Add New data to stored data table
-            self.Data = numpy.append(self.Data, data_values, axis=0)
+            self.Data.append(data_values)
 
             # Signal to debug variable panel to refresh
             self.Parent.HasNewData = True
@@ -337,7 +338,7 @@
         if tick is not None and self.Data is not None:
 
             # Return current value and forced flag if data empty
-            if len(self.Data) == 0:
+            if self.Data.count == 0:
                 return self.Value, self.IsForced()
 
             # Get index of nearest data from tick given
@@ -345,9 +346,9 @@
 
             # Get value and forced flag at given index
             value, forced = \
-                self.RawData[int(self.Data[idx, 2])] \
+                self.RawData[int(self.Data.view[idx, 2])] \
                 if self.VariableType in ["STRING", "WSTRING"] \
-                else self.Data[idx, 1:3]
+                else self.Data.view[idx, 1:3]
 
             if self.VariableType in ["TIME", "TOD", "DT", "DATE"]:
                 value = timedelta(seconds=value)
@@ -380,10 +381,10 @@
             return None
 
         # Extract data ticks
-        ticks = self.Data[:, 0]
+        ticks = self.Data.view[:, 0]
 
         # Get nearest data from tick
-        idx = numpy.argmin(abs(ticks - tick))
+        idx = np.searchsorted(ticks, tick)
 
         # Adjust data index according to constraint
         if adjust < 0 and ticks[idx] > tick and idx > 0 or \