I believe it may be able to done to monitor but not to provide protection. It is imperative that a protective system be fail safe if ti configuration as you have described implies that you are looking for wireless protection as was stated: "digital form to a 'protective terminal' with no copper, via Ethernet or something."
#130723 - 11/02/0606:49 AMRe: Protective Relays with no ADC
I'm not sure I understand your need very clearly, but if your looking to monitor your inputs, and transmit that data wirelessly, or via the ethernet, this would work. http://www.electroind.com/shark100s.html
#130724 - 11/02/0608:58 AMRe: Protective Relays with no ADC
There are many ways to transfer protective digital info. Presently, most utilities are going to fibre, since the high EMF during fault conditions has no affect on the signal being transmitted. The fiber signal is also reliable enough for protection of xfmrs, transmission lines, buses, etc because the devices used to transmit the signal through the fiber have a self-monitoring scheme built in. The protection digital signal can travel over a 100 miles through single-mode fiber. If you feel froggy, you can check all you want at Schweitzer Engineering Labs (SEL) at www.selinc.com. Have fun reading.
[This message has been edited by BugMan (edited 11-02-2006).]
#130726 - 11/11/0611:14 PMRe: Protective Relays with no ADC