Connection between two ZigBee S2D using XBee Smart Shield

I was trying connecting two XBee S2D to Arduino Uno Board using SainSmart XBee Shield Module but I was unable to make a connection or a network.

Also, in XBee S2D we are unable to make them as End Devices, i.e., we can only configure the devices as Coordinators or Routers. So, is there any way to make them as End Devices so that we can establish a Mesh, Star or Cluster Network.