diff --git a/secop_psi/ppms.py b/secop_psi/ppms.py
index c5172bd..5cbfe7f 100644
--- a/secop_psi/ppms.py
+++ b/secop_psi/ppms.py
@@ -73,7 +73,7 @@ class Main(Communicator):
     """ppms communicator module"""
 
     pollinterval = Parameter('poll interval', FloatRange(), readonly=False, default=2)
-    data = Parameter('internal', StringType(), poll=True, export=True,  # export for test only
+    data = Parameter('internal', StringType(), poll=True, export=False,  # export for test only
                      default="", readonly=True)
 
     class_id = Property('Quantum Design class id', StringType(), export=False)
@@ -89,6 +89,7 @@ class Main(Communicator):
     pollerClass = Poller
 
     def earlyInit(self):
+        super().earlyInit()
         self.modules = {}
         self._ppms_device = ppmshw.QDevice(self.class_id)
         self.lock = threading.Lock()
@@ -99,8 +100,9 @@ class Main(Communicator):
     def communicate(self, command):
         """GPIB command"""
         with self.lock:
+            self.log.debug('> %s' % command)
             reply = self._ppms_device.send(command)
-            self.log.debug("%s|%s", command, reply)
+            self.log.debug('< %s' % reply)
             return reply
 
     def read_data(self):
@@ -143,23 +145,9 @@ class PpmsMixin:
     pollinterval = Parameter('', FloatRange(), needscfg=False, export=False)
 
     def initModule(self):
+        super().initModule()
         self._iodev.register(self)
 
-    def startModule(self, started_callback):
-        # no polls except on main module
-        started_callback()
-
-    def read_value(self):
-        # polling is done by the main module
-        # and PPMS does not deliver really more fresh values when polled more often
-        return Done
-
-    def read_status(self):
-        # polling is done by the main module
-        # and PPMS does not deliver really fresh status values anyway: the status is not
-        # changed immediately after a target change!
-        return Done
-
     def update_value_status(self, value, packed_status):
         # update value and status
         # to be reimplemented for modules looking at packed_status
@@ -176,7 +164,7 @@ class PpmsMixin:
 class Channel(PpmsMixin, HasIodev, Readable):
     """channel base class"""
 
-    value = Parameter('main value of channels', poll=True)
+    value = Parameter('main value of channels', poll=False, needscfg=False)
     enabled = Parameter('is this channel used?', readonly=False, poll=False,
                         datatype=BoolType(), default=False)