NEC KT-X46UN User Manual page 23

NEC Display Wall Calibrator - UsEr's GUiDE | 
Next the connection method of the displays is selected.
In this example a LAN connection from the host PC will be used. The first display has been assigned IP address
192.168.0.1. All of the remaining 5 displays in the video wall will use an RS232 daisy-chain to communicate via the
LAN connection on the first display.
Next the connection method for the remaining displays must be selected. Two options are available in this case
because displays connected to the LAN can either have their own IP address and be connected to the LAN, or they
can be connected to the first display via daisy-chained RS232.
In this example they are daisy-chained to the first display by RS232.