The Topfield 5200 has a cardreader and two CI slots. The cardreader is connected to the embedded Conax CAM, and can not be used for Ziggo.
You need to buy an Alphacrypt CAM, put it in of the CI slots, and put your Ziggo card in the Alphacrypt.
The Alphacrypt is the only CAM that works with Ziggo, although Ziggo doesn't support it.
When you order the Alphacrypt make sure it has the latest fimware release (3.18).