diff -r 1b4b335e19ea -r b98d9e08231f etherlab/EthercatSlave.py
--- a/etherlab/EthercatSlave.py	Wed Nov 13 11:21:04 2019 +0100
+++ b/etherlab/EthercatSlave.py	Mon Nov 25 08:10:45 2019 +0100
@@ -73,6 +73,8 @@
     def __init__(self):
         # ----------- call ethercat mng. function --------------
         self.CommonMethod = _CommonSlave(self)
+        self.SelectedRxPDOIndex = []
+        self.SelectedTxPDOIndex = []
 
     def GetIconName(self):
         return "Slave"