--- a/modbus/modbus.py	Fri Nov 23 11:01:20 2018 +0100
+++ b/modbus/modbus.py	Fri Nov 23 12:13:24 2018 +0100
@@ -25,8 +25,9 @@
 
 from __future__ import absolute_import
 import os
+from six.moves import xrange
+
 from modbus.mb_utils import *
-
 from ConfigTreeNode import ConfigTreeNode
 from PLCControler import LOCATION_CONFNODE, LOCATION_VAR_MEMORY