Triconex 4701X / 4703X are I/O-bus interface modules for the 8131X Tricon CX I/O expansion chassis. The 4701X is the serial-to-serial IMSS, and the 4703X is the fiber-to-fiber IMFF. Each module occupies the interface position at the left of the expansion chassis and carries the processor I/O-bus path into the chassis backplane before forwarding that path to the next supported segment.

On Triconex 4701X / 4703X, the connector roles follow the selected medium. The 4701X receives and retransmits the RS-485 I/O bus through shielded copper RJ-45 ports. The 4703X receives the IOP bus through an SFP fiber input, can forward it through a fiber output, and also provides an RS-485 serial output for the next copper segment. The incoming and outgoing cables must therefore be assigned by port function rather than by connector appearance alone.

Distance and grounding are linked to the media choice on Triconex 4701X / 4703X. A 4701X copper segment remains within the specified 30 m limit and preserves an electrical path between chassis, whereas 4703X fiber reach follows the matched SFP pair and removes the conductive bus connection across that optical segment. The interface selection consequently defines both the cable set and the way consecutive expansion chassis are joined.