diff --git a/script/camtool.py b/script/camtool.py
index d527bf6..df3201d 100644
--- a/script/camtool.py
+++ b/script/camtool.py
@@ -49,12 +49,12 @@ class CamTool(DeviceBase):
         self.num_images = 1
         self.image = CamToolImage(self)
         set_device_alias(self.image, name + " image")
-
-        self.com_x = [1.0,2.0, 3.0]
+        
         class CamToolComX(Readable):
             def read(self):        
-                return mean(self.com_x)
+                return mean(self.com_x_samples)
         self.com_x_mean = CamToolComX()
+        self.com_x_mean.com_x_samples = [1.0,2.0, 3.0]
         set_device_alias(self.com_x_mean, name + " com x mean")
 
     def doInitialize(self):