Check out the chapter “Maintaining the Ethernet-Based I/O Unit” in the form 1460 LEGACY SNAP ETHERNET-BASED I/O UNITS USER’S GUIDE and start looking for a USB-RS232 9pin adaptor and a version of XP or older Windows operating system.
1460 SNAP Ethernet Based IO Units Users Guide.pdf
You will also need to download a copy of ioManager, a configuration tool used to assign IP addresses to legacy Opto 22 Ethernet-based controllers and I/O units. It is available as part of the ioProject Basic and Professional software suites.