The B224BI-WH and B224BI-IV isolator bases are intended for use in an intelligent system. Isolator bases prevent an entire communications loop from being disabled when a short circuit occurs. They accomplish this by isolating that part of the loop containing the short from the remainder of the circuit. These bases also automatically restore the entire loop when the cause of the short circuit is corrected. In general, up to 25 addressable devices may be isolated between isolator bases.