Jaycars 4 channel IP based remote Contol Kit.

The kit is prebuilt. It's only a kit in the sense that the boards aren't in a case and don't have a power supply included. Google Aviosys and 9202 and you should be able to find the manual (even though the unit is no longer supported by Aviosys.

I returned mine for a refund when I found that after a power failure channels 3 and 4, the NO relays, always turned on again which isn't very useful for remotely powering something up.

Although the mainboard looks like the same PCB is used for the 8 channel version I doubt that it would be easily modified unless you could reverse engineer their firmware.