diff --git a/cfg/attocube_cfg.py b/cfg/attocube_cfg.py
index a1764dc..e703cb9 100644
--- a/cfg/attocube_cfg.py
+++ b/cfg/attocube_cfg.py
@@ -7,9 +7,10 @@ Mod('r',
     'frappy_psi.attocube.Axis',
     'ANRv220-F3-02882',
     axis = 1,
-    unit = 'deg',
+    value = Param(unit='deg'),
     tolerance = 0.01,
-    target_limits = (0, 360),
+    target_min = 0,
+    target_max = 360
     # gear = 1.2,
 )
 
diff --git a/frappy_psi/attocube.py b/frappy_psi/attocube.py
index 62ba423..ee0957e 100644
--- a/frappy_psi/attocube.py
+++ b/frappy_psi/attocube.py
@@ -19,7 +19,8 @@
 
 import sys
 import time
-from frappy.core import Drivable, Parameter, Command, Property, ERROR, WARN, BUSY, IDLE, Done, nopoll, TupleOf
+from frappy.core import Drivable, Parameter, Command, Property, \
+    ERROR, WARN, BUSY, IDLE, Done, nopoll, Limit
 # from frappy.features import HasSimpleOffset
 from frappy.datatypes import IntRange, FloatRange, StringType, BoolType
 from frappy.errors import ConfigError, BadValueError
@@ -30,50 +31,18 @@ from PyANC350v4 import Positioner
 DIRECTION_NAME = {1: 'forward', -1: 'backward'}
 
 
-class FreezeStatus:
-    """freeze status for some time
-
-    hardware quite often does not treat status correctly: on a target change it
-    may take some time to return the 'busy' status correctly.
-
-    in classes with this mixin, within :meth:`write_target` call
-
-    self.freeze_status(0.5, BUSY, 'changed target')
-
-    a wrapper around read_status will take care that the status will be the given value,
-    for at least the given delay. This does NOT cover the case when self.status is set
-    directly from an other method.
-    """
-    __freeze_status_until = 0
-
-    def __init_subclass__(cls):
-        def wrapped(self, inner=cls.read_status):
-            if time.time() < self.__freeze_status_until:
-                return Done
-            return inner(self)
-
-        wrapped.poll = True
-        cls.read_status = wrapped
-        super().__init_subclass__()
-
-    def freeze_status(self, delay, code=BUSY, text='changed target'):
-        """freezze status to the given value for the given delay"""
-        self.__freeze_status_until = time.time() + delay
-        self.status = code, text
-
-
-class Axis(FreezeStatus, Drivable):
+class Axis(Drivable):
     axis = Property('axis number', IntRange(0, 2), 0)
     value = Parameter('axis position', FloatRange(unit='deg'))
     frequency = Parameter('frequency', FloatRange(1, unit='Hz'), readonly=False)
     amplitude = Parameter('amplitude', FloatRange(0, unit='V'), readonly=False)
-    gear = Parameter('gear factor', FloatRange(), readonly=False, default=1)
+    gear = Parameter('gear factor', FloatRange(), readonly=False, value=1)
     tolerance = Parameter('positioning tolerance', FloatRange(0, unit='$'), readonly=False, default=0.01)
     output = Parameter('enable output', BoolType(), readonly=False)
     info = Parameter('axis info', StringType())
     statusbits = Parameter('status bits', StringType())
-    target_limits = Parameter('target limits', TupleOf(FloatRange(), FloatRange()), readonly=False)
-
+    target_min = Limit()
+    target_max = Limit()
 
     _hw = Positioner()
     _scale = 1  # scale for custom units
@@ -85,16 +54,7 @@ class Axis(FreezeStatus, Drivable):
     _history = None
     _check_sensor = False
     _try_count = 0
-
-    def __init__(self, name, logger, opts, srv):
-        unit = opts.pop('unit', 'deg')
-        # opts['value.unit'] = unit
-        try:
-            # self._scale = self.SCALES[unit] * opts.get('gear', 1)
-            self._scale = self.SCALES['deg'] * opts.get('gear', 1)
-        except KeyError as e:
-            raise ConfigError('unsupported unit: %s' % unit)
-        super().__init__(name, logger, opts, srv)
+    __freeze_until = 0
 
     def write_gear(self, value):
         self._scale = self.SCALES[self.parameters['value'].datatype.unit] * self.gear
@@ -144,7 +104,15 @@ class Axis(FreezeStatus, Drivable):
         self._hw.setAxisOutput(self.axis, enable=value, autoDisable=0)
         return value
 
+    def freeze_status(self, delay, code=BUSY, text='changed target'):
+        """freeze status to the given value for the given delay"""
+        self.__freeze_until = time.time() + delay
+        self.status = code, text
+
     def read_status(self):
+        if time.time() < self.__freeze_until:
+            return self.status
+        self.__freeze_until = 0
         statusbits = self._hw.getAxisStatus(self.axis)
         sensor, self.output, moving, attarget, eot_fwd, eot_bwd, sensor_error = statusbits
         self.statusbits = ''.join((k for k, v in zip('SOMTFBE', statusbits) if v))
@@ -214,7 +182,7 @@ class Axis(FreezeStatus, Drivable):
                 self.log.warn('%r', e)
         self._history = [self.value]
         self._idle_status = IDLE, ''
-        self.freeze_status(1, BUSY, 'changed target')
+        self.freeze_status(1)
         self.setFastPoll(True, 1)
         return value