diff --git a/fhem/FHEM/11_OWDevice.pm b/fhem/FHEM/11_OWDevice.pm
index f5ee50a1a..40f5e32d3 100644
--- a/fhem/FHEM/11_OWDevice.pm
+++ b/fhem/FHEM/11_OWDevice.pm
@@ -24,6 +24,7 @@
 
 # Todos:
 # - stateFormat via Interface
+# - warum wird jeder Wert 2x geloggt?
 
 package main;
 
@@ -40,9 +41,9 @@ OWDevice_Initialize($)
   $hash->{GetFn}     = "OWDevice_Get";
   $hash->{SetFn}     = "OWDevice_Set";
   $hash->{DefFn}     = "OWDevice_Define";
-  $hash->{AttrFn}     = "OWDevice_Attr";
+  $hash->{AttrFn}    = "OWDevice_Attr";
 
-  $hash->{AttrList}  = "trimvalues polls interfaces model loglevel:0,1,2,3,4,5 ".  
+  $hash->{AttrList}  = "IODev trimvalues polls interfaces model loglevel:0,1,2,3,4,5 ".  
                        $readingFnAttributes;
 }
 
@@ -471,7 +472,6 @@ OWDevice_Define($$)
       <li>2413 1-Wire Dual Channel Addressable Switch</li>
       <li>2405 Addressable Switch</li>
       <li>2406, 2407 - Dual Addressable Switch with 1kbit Memory</li>
-      <li>2413 1-Wire Dual Channel Addressable Switch</li>
       <li>2408 1-Wire 8 Channel Addressable Switch</li>
       <li>LCD 1-wire LCD controller by Louis Swart</li>
     </ul>
@@ -552,6 +552,14 @@ OWDevice_Define($$)
   <a name="OWDeviceattr"></a>
   <b>Attributes</b>
   <ul>
+    <a name="IODev"></a>
+    <li>IODev: 
+        Set the OWServer device which should be used for sending and receiving data
+        for this OWDevice. Note: Upon startup fhem assigns each OWDevice
+        to the last previously defined OWServer. Thus it is best if you define OWServer
+        and OWDevices in blocks: first define the first OWServer and the OWDevices that
+        belong to it, then continue with the next OWServer and the attached OWDevices, and so on.
+    </li>
     <li>trimvalues: removes leading and trailing whitespace from readings. Default is 1 (on).</li>
     <li>polls: a comma-separated list of readings to poll. This supersedes the list of default readings to poll.</li>
     <li>interfaces: supersedes the interfaces exposed by that device.</li>