Where did you get the antminer from? If you bought it secondhand then ask the seller what the ip address is/was.

Or download IPScanner (not the bitmain one) and scan your network but using 192.168.0.1 to 192.168.1.1 range and see if it finds it.

1. Figure out the powerline adapter link. Follow the instructions. Test it with some easy device.
2. When you got that working, then you can try to connect the miner and setup it by first finding it's IP address via router web setting page for example and then following instructions available in the Bitmain Antminer S7 manual (www.bitmain.com) or instructions available here at the forum.