A process control system is provided having a plurality of I/O devices in
communication using a bus. A primary redundant I/O device and a secondary
redundant I/O device are coupled to the bus, where the secondary
redundant I/O device is programmed to detect a primary redundant I/O
device fault. The secondary redundant I/O device, upon detecting the
primary redundant I/O device fault, publishes a primary redundant I/O
device fault message on the bus. The controller may deactivate the
primary redundant I/O device and activate the secondary redundant I/O
device responsive to the primary redundant I/O device fault message.