I/o carrier and backplane for industrial process control systems

An I/O device configured to couple a plurality of process control field devices to a process controller controlling a process in an industrial plant, the I/O device comprising:

• a plurality of electronic marshalling component (EMC) slots;
• one or more EMCs each physically and communicatively coupled to a respective EMC slot;
• one or more I/O processor module slots;
• one or more I/O processor modules each physically and communicatively coupled to a respective I/O processor module slot;
• a backplane comprising:
• a first bus configured to communicatively couple each of the plurality of electronic marshalling component (EMC) slots to each of the one or more I/O processor module slots, the first bus having a bandwidth of 10 Mbps or greater;
• and
• a second bus, redundant to the first bus, configured to communicatively couple each of the plurality of EMC slots to each the one or more I/O processor module slots, the second bus having a bandwidth of 10 Mbps or greater;
• wherein, for each pair of a one of the plurality of EMC slots and a one of the one or more I/O processor module slots, a first path length of the first bus between the pair is the same as a second path length of the second bus between the pair, such that data transmitted between the pair on the first bus has a same latency as data transmitted between the pair on the second bus;
• and
• one or more communication ports, each communicatively coupled to each of the one or more I/O processor module slots via the backplane, and each configured to communicatively couple the each of the one or more I/O processor module slots to the process controller.