--- a/etherlab/EthercatCFileGenerator.py	Sat Sep 29 12:55:56 2018 +0300
+++ b/etherlab/EthercatCFileGenerator.py	Sat Sep 29 13:04:33 2018 +0300
@@ -337,7 +337,7 @@
                             if slave_variables.get((index, subindex), None) is not None:
                                 pdo_mapping_match["matching"] += 1
 
-                        if pdo.getFixed() != True:
+                        if pdo.getFixed() is not True:
                             pdo_mapping_match["matching"] += \
                                 module_extra_params["max_pdo_size"] - \
                                 pdo_mapping_match["count"]
@@ -438,7 +438,7 @@
                              "type": pdo_type,
                              "entries": entries_infos,
                              "entries_number": len(entries_infos),
-                             "fixed": pdo.getFixed() == True})
+                             "fixed": pdo.getFixed() is True})
 
                 if PdoConfig and PdoAssign:
                     dynamic_pdos = {}