Cable connections are the conventional way to connect large numbers of DGT serial tournament e-Boards to the PC for live internet broadcasting of chess games.  
Strings of 12 e-Boards are made using the basic connection set (article code 10657) to connect the first board to the PC and additional connection sets (article code 10658) to connect each of the next 11 boards to the first board. 
Smart Board Connection Materials
Connection Material for 1st Tournament e-Board (Product Code 10657)

This connection set is required to connect the first of every 12 serial tournament e-Boards. It contains a power supply (suitable for 12 boards), a board-to-bus cable, a PC-to-bus cable, 5m patch cable, 20m patch cable and 4 connection boxes. A serial-to-USB converter is also included in this set.