State monitoring device (100, 200, 300) for monitoring the state of a mechanical machine component, comprising: a vibration sensor for detecting mechanical vibrations at the machine component, wherein the vibration sensor is configured as a MEMS-based vibration sensor on a semiconductor basis; a controller, which is coupled to the vibration sensor and is configured to determine a state of the machine component based on measurement data generated by the vibration sensor; and a wired communication interface coupled to the controller by communication technology for communication with an external control device, wherein the controller is configured, based on a request for transmission of information about the state of the machine component, to transmit the requested information via the wired communication interface, wherein the state monitoring device has a first input for connecting at least one external resistance temperature sensor for detecting at least one temperature of the machine component, wherein the first input comprises a plurality of RTD lines connected to the at least one external resistance temperature sensor, wherein the state monitoring device comprises an internal current source, which is configured to drive a predetermined current via the RTD lines through the at least one external resistance temperature sensor, and wherein the state monitoring device comprises a first analog-digital (A/D) converter, which is configured to detect a voltage drop across the RTD lines and to forward it as a converted digital value to the controller, wherein the controller is configured to determine the state of the machine component further based on measurement data of the first input. a vibration sensor for detecting mechanical vibrations at the machine component, wherein the vibration sensor is configured as a MEMS-based vibration sensor on a semiconductor basis; a controller, which is coupled to the vibration sensor and is configured to determine a state of the machine component based on measurement data generated by the vibration sensor; and a wired communication interface coupled to the controller by communication technology for communication with an external control device, wherein the controller is configured, based on a request for transmission of information about the state of the machine component, to transmit the requested information via the wired communication interface, wherein the state monitoring device has a first input for connecting at least one external resistance temperature sensor for detecting at least one temperature of the machine component, wherein the first input comprises a plurality of RTD lines connected to the at least one external resistance temperature sensor, wherein the state monitoring device comprises an internal current source, which is configured to drive a predetermined current via the RTD lines through the at least one external resistance temperature sensor, and wherein the state monitoring device comprises a first analog-digital (A/D) converter, which is configured to detect a voltage drop across the RTD lines and to forward it as a converted digital value to the controller, wherein the controller is configured to determine the state of the machine component further based on measurement data of the first input.