<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:fillAfter="true" >
    
    <alpha 
        android:fromAlpha="0"
        android:toAlpha="1"
        android:repeatMode="reverse"
        android:duration="600"
        android:repeatCount="infinite"
        android:startOffset="200" />
</set>