DPC-1 5417-557 and DPC-USB 5417-1251 are special configuration cables for a peer to peer RS232 (DPC-1) and USB connection
between easYgen-1500, easYgen-2000, DTSC-200, LS5 controllers and your Laptop.
The RJ45 plug is a special RS232 interface (non-standard voltage levels) and not an Ethernet port.
The small black box is a galvanic isolation and a voltage divider from 5.o VDC to 3.5 VDC
You can download USB driver here:
https://wss.woodward.com/manuals/PGC/SW_Tools/USB_Drivers
5417-1251