Add OPC_time_out as property

This allows us to see when the OPC-US server is not responding.

crossechoTangoDev/Crossecho.xmi

@@ -15,6 +15,11 @@
       <status abstract="false" inherited="false" concrete="true" concreteHere="true"/>
       <DefaultPropValue>55555</DefaultPropValue>
     </deviceProperties>
+    <deviceProperties name="OPC_time_out" description="">
+      <type xsi:type="pogoDsl:ULongType"/>
+      <status abstract="false" inherited="false" concrete="true" concreteHere="true"/>
+      <DefaultPropValue>1000</DefaultPropValue>
+    </deviceProperties>
     <commands name="State" description="This command gets the device state (stored in its device_state data member) and returns it to the caller." execMethod="dev_state" displayLevel="OPERATOR" polledPeriod="0">
       <argin description="none">
         <type xsi:type="pogoDsl:VoidType"/>