diff --git a/revpicommander/aclmanager.py b/revpicommander/aclmanager.py
index 88a15f2..26b5d3f 100644
--- a/revpicommander/aclmanager.py
+++ b/revpicommander/aclmanager.py
@@ -15,7 +15,7 @@ from ui.aclmanager_ui import Ui_diag_aclmanager
 class AclManager(QtWidgets.QDialog, Ui_diag_aclmanager):
     """ACL manager."""
 
-    def __init__(self, parent):
+    def __init__(self, parent=None):
         super(AclManager, self).__init__(parent)
         self.setupUi(self)
         self.setFixedSize(self.size())
diff --git a/revpicommander/debugios.py b/revpicommander/debugios.py
index 0021afa..4a012b1 100644
--- a/revpicommander/debugios.py
+++ b/revpicommander/debugios.py
@@ -29,6 +29,9 @@ class DebugIos(QtWidgets.QMainWindow, Ui_win_debugios):
         self.setWindowTitle("{0} - {1}".format(position, name))
         self.gb_io.setTitle(self.gb_io.title().format(name))
 
+        self.__qwa = {}
+        """Quick widget access."""
+
         self.position = position
         self.name = name
         self.inputs = inputs.copy()
@@ -72,6 +75,7 @@ class DebugIos(QtWidgets.QMainWindow, Ui_win_debugios):
             name = val.objectName()
             if name not in lst_names:
                 # Remove old io from layout
+                del self.__qwa[name]
                 layout.removeRow(layout.getWidgetPosition(val)[0])
 
         counter = -1
@@ -147,6 +151,7 @@ class DebugIos(QtWidgets.QMainWindow, Ui_win_debugios):
                 val.valueChanged.connect(self._change_sbx_dvalue)
 
         val.setObjectName(name)
+        self.__qwa[name] = val
         return val
 
     @QtCore.pyqtSlot(int)
@@ -267,7 +272,8 @@ class DebugIos(QtWidgets.QMainWindow, Ui_win_debugios):
         :param io_name: Name of IO
         :return: (actual value, last value) <class 'tuple'>
         """
-        child = self.findChild(self.search_class, io_name)
+        # child = self.findChild(self.search_class, io_name)
+        child = self.__qwa[io_name]
         actual_value = child.value()
         last_value = child.value() if child.property("last_value") is None else child.property("last_value")
         if child.property("frm"):
@@ -285,7 +291,8 @@ class DebugIos(QtWidgets.QMainWindow, Ui_win_debugios):
         :param io_name: Name of IO
         :param value: Process value as <class 'bool'> or <class 'bytes'>
         """
-        child = self.findChild(self.search_class, io_name)
+        # child = self.findChild(self.search_class, io_name)
+        child = self.__qwa[io_name]
         if child.property("frm"):
             value = struct.unpack(child.property("frm"), value)[0]
         elif type(value) == bytearray:
@@ -300,7 +307,8 @@ class DebugIos(QtWidgets.QMainWindow, Ui_win_debugios):
         :param io_name: Name of IO
         :param value: New value as bytes or bool for widget
         """
-        child = self.findChild(self.search_class, io_name)
+        # child = self.findChild(self.search_class, io_name)
+        child = self.__qwa[io_name]
         if child.property("frm"):
             value = struct.unpack(child.property("frm"), value)[0]
         elif type(value) == bytearray:
diff --git a/revpicommander/mqttmanager.py b/revpicommander/mqttmanager.py
index 0fb6525..44e8bab 100644
--- a/revpicommander/mqttmanager.py
+++ b/revpicommander/mqttmanager.py
@@ -14,7 +14,7 @@ from ui.mqttmanager_ui import Ui_diag_mqtt
 class MqttManager(QtWidgets.QDialog, Ui_diag_mqtt):
     """MQTT settings for option window."""
 
-    def __init__(self, parent):
+    def __init__(self, parent=None):
         super(MqttManager, self).__init__(parent)
         self.setupUi(self)
         self.setFixedSize(self.size())
diff --git a/revpicommander/revpicommander.py b/revpicommander/revpicommander.py
index e648d1e..e630d4e 100755
--- a/revpicommander/revpicommander.py
+++ b/revpicommander/revpicommander.py
@@ -52,7 +52,7 @@ class RevPiCommander(QtWidgets.QMainWindow, Ui_win_revpicommander):
         # Load sub windows
         self.diag_connections = RevPiPlcList(self)
         self.diag_search = AvahiSearch(self)
-        self.diag_info = RevPiInfo(self, __version__)
+        self.diag_info = RevPiInfo(__version__, self)
         self.diag_options = RevPiOption(self)
         self.diag_program = RevPiProgram(self)
         self.win_log = revpilogfile.RevPiLogfile(self)
diff --git a/revpicommander/revpiinfo.py b/revpicommander/revpiinfo.py
index 493c72a..2550548 100644
--- a/revpicommander/revpiinfo.py
+++ b/revpicommander/revpiinfo.py
@@ -13,7 +13,7 @@ from ui.revpiinfo_ui import Ui_diag_revpiinfo
 class RevPiInfo(QtWidgets.QDialog, Ui_diag_revpiinfo):
     """Version information window."""
 
-    def __init__(self, parent, version: str):
+    def __init__(self, version: str, parent=None):
         super(RevPiInfo, self).__init__(parent)
         self.setupUi(self)
 
diff --git a/revpicommander/revpilogfile.py b/revpicommander/revpilogfile.py
index 21a201b..d89dd55 100644
--- a/revpicommander/revpilogfile.py
+++ b/revpicommander/revpilogfile.py
@@ -104,7 +104,7 @@ class DataThread(QtCore.QThread):
 class RevPiLogfile(QtWidgets.QMainWindow, Ui_win_revpilogfile):
     """Log file viewer for daemon and plc program log."""
 
-    def __init__(self, parent):
+    def __init__(self, parent=None):
         u"""Init RevPiLogfile-Class."""
         super(RevPiLogfile, self).__init__(parent)
         self.setupUi(self)
diff --git a/revpicommander/revpioption.py b/revpicommander/revpioption.py
index 2d5770c..a63ddc8 100644
--- a/revpicommander/revpioption.py
+++ b/revpicommander/revpioption.py
@@ -16,7 +16,7 @@ from ui.revpioption_ui import Ui_diag_options
 class RevPiOption(QtWidgets.QDialog, Ui_diag_options):
     """Set options of RevPiPyLoad."""
 
-    def __init__(self, parent):
+    def __init__(self, parent=None):
         super(RevPiOption, self).__init__(parent)
         self.setupUi(self)
         self.setFixedSize(self.size())