Modular interface system for connecting a control device and field devices

A modular interface system for connecting at least one control device and field devices, in particular actuators and/or sensors, comprising:

• a modular Single Pair Ethernet-based (SPE-based bus system which has an SPE-based twin-core line and a plurality of first SPE-based connectors which are electrically connected to the SPE-based twin-core line,
• a first module which has a second SPE-based connector and a first interface, wherein the second SPE-based connector is designed for electrical and mechanical coupling with one of the plurality of first SPE-based connectors of the SPE-based bus system, and the first interface is designed for the electrical connection of a control device, wherein the first module is designed to enable the communication of a control device which can be connected to the first interface, via the SPE-based bus system, according to a first communication protocol, and also
• at least one second module which has a third SPE-based connector which is designed for electrical and mechanical coupling to another of the plurality of first SPE-based connectors of the SPE-based bus system, and with at least one second interface designed to connect a field device, wherein the second module is designed to enable the data transmission of a field device which can be connected to the at least one second interface via the SPE-based bus system, according to the first communication protocol, and/or a third module, which has a fourth SPE-based connector which is designed for electrical and mechanical coupling with one of the plurality of first SPE-based connectors of the SPE-based bus system, at least one third and fourth interface which each are designed for connecting a field device, and which has a switch, which has a first port assigned to the fourth SPE-based connector, a second port assigned to the third interface, and a third port assigned to the fourth interface, wherein the second port and the third interface are based on SPE technology or on a first Ethernet technology that is not SPE technology, wherein the third port and the fourth interface are based on SPE technology or on a second Ethernet technology that is not SPE technology, wherein the first and second Ethernet technology are the same or different, wherein the third module is designed to enable the communication of a field device which can be connected to the third interface, and the communication of a field device which can be connected to the fourth interface, via the SPE-based bus system, according to the first communication protocol.