Patent ID: 7797061
Filing Date: 2010-09-14
Classification: G05B

Abstract:
1. An apparatus for use in a redundant fieldbus system, the apparatus comprising: first terminals adapted to connect to a first fieldbus cable, the first terminals coupled to a field device to provide power and communications from a fieldbus network to the field device; second terminals adapted to connect to a second fieldbus cable, the second terminals coupled to the field device to provide power and communications from the fieldbus network to the field device; a first diagnostic circuit connected between the first terminals and the field device, the first diagnostic circuit adapted to detect an active power source associated with the first terminals and to isolate a non-active power source from the field device; and a second diagnostic circuit connected between the second terminals and the field device, the second diagnostic circuit adapted to detect an active power source associated with the second terminals and to isolate a non-active power source from the field device, the first and second diagnostic circuits adapted to select and provide communication signals from either the first terminals or the second terminals to the field device.