diff --git a/secop/modules.py b/secop/modules.py
index ed1df5d..c4e1d83 100644
--- a/secop/modules.py
+++ b/secop/modules.py
@@ -419,6 +419,8 @@ class Module(HasAccessibles):
     def announceUpdate(self, pname, value=None, err=None, timestamp=None):
         """announce a changed value or readerror"""
         pobj = self.parameters[pname]
+        timestamp = timestamp or time.time()
+        changed = pobj.value != value or timestamp > (pobj.timestamp or 0) + 1
         if value is not None:
             pobj.value = value  # store the value even in case of error
         if err:
@@ -431,7 +433,9 @@ class Module(HasAccessibles):
                 pobj.value = pobj.datatype(value)
             except Exception as e:
                 err = secop_error(e)
-        pobj.timestamp = timestamp or time.time()
+            if not changed:
+                return  # experimental: do not update unchanged values within 1 sec
+        pobj.timestamp = timestamp
         pobj.readerror = err
         if pobj.export:
             self.DISPATCHER.announce_update(self.name, pname, pobj)
diff --git a/secop_psi/dpm.py b/secop_psi/dpm.py
index 6cb57d6..4069c6c 100644
--- a/secop_psi/dpm.py
+++ b/secop_psi/dpm.py
@@ -116,28 +116,37 @@ class DPM3(HasIodev, Drivable):
  
     def read_value(self):
         value = float(self._iodev.communicate('*1B1'))
-        if self._target is not None:
-            mot = self._motor
-            if self._direction * (self._target - value) > 0:
-                if not mot.isBusy():
-                    step = self.step * self._direction
-                    mot.write_target(mot.value + step)
+        mot = self._motor
+        if self._target is None:
+            if mot.isBusy():
+                self.status = self.Status.IDLE, 'stopping'
+            else:
+                self.status = self.Status.IDLE, ''
+        else:
+            if self._direction * (self._target - value) > 0:
+                if self._mot_target != mot.target:
+                    self.stop()
+                    self.status = self.Status.IDLE, 'motor was stopped'
+                elif not mot.isBusy():
+                    step = self.step * self._direction
+                    mot_target = mot.value + step
+                    self._mot_target = mot.write_target(mot_target)
             else:
-                print(value)
                 self.stop()
                 self.status = self.Status.IDLE, 'target reached'
         return value
     
     def write_target(self, target):
         self._target = target
+        self._started = True
         if target - self.value > 0:
             self._direction = 1
         else:
             self._direction = -1
-        print('direction', self._direction)
         self.status = self.Status.BUSY, 'moving motor'
         if self._motor.status[0] == self.Status.ERROR:
             self._motor.reset()
+        self._mot_target = self._motor.target
         return target
 
     @Command()
diff --git a/secop_psi/trinamic.py b/secop_psi/trinamic.py
index 67c9aa2..b62e3aa 100644
--- a/secop_psi/trinamic.py
+++ b/secop_psi/trinamic.py
@@ -81,7 +81,7 @@ class Motor(PersistentMixin, HasIodev, Drivable):
     #                           TupleOf(IntRange(0, 15), IntRange(0, 15)),
     #                           default=(8, 0))
 
-    value = Parameter('motor position', FloatRange(unit='deg', fmtstr='%.3f'))
+    value = Parameter('motor position', FloatRange(unit='deg', fmtstr='%.3f'), poll=False, default=0)  # polling by read_status
     zero = PersistentParam('zero point', FloatRange(unit='$'), readonly=False, default=0)
     encoder = HwParam('encoder reading', FloatRange(unit='$', fmtstr='%.1f'),
                       209, ANGLE_SCALE, readonly=True, initwrite=False, persistent=True)
@@ -124,7 +124,8 @@ class Motor(PersistentMixin, HasIodev, Drivable):
     
 
     iodevClass = BytesIO
-    fast_pollfactor = 0.001  # poll as fast as possible when busy
+    # fast_pollfactor = 0.001  # poll as fast as possible when busy
+    fast_pollfactor = 0.05
     _started = 0
     _calcTimeout = True
     _need_reset = None
@@ -400,6 +401,7 @@ class Motor(PersistentMixin, HasIodev, Drivable):
     def stop(self):
         self.comm(MOTOR_STOP, 0)
         self.status = self.Status.IDLE, 'stopped'
+        self.target = self.value  # indicate to customers that this was stopped
         self._started = 0
 
     #@Command()