CONDITION MONITORING DEVICE FOR MONITORING THE CONDITION OF A MECHANICAL MACHINE COMPONENT

Description

[0001] The invention relates to a condition monitoring device for monitoring the condition of a mechanical machine component. In particular, the invention relates to an IO-Link device for condition monitoring.

[0002] Condition monitoring (CM) involves monitoring the condition of machines and their mechanical assemblies. Its primary goal is to monitor the condition of bearings and detect bearing damage early to prevent machine failure. According to VDI standard 3832, the condition of the bearing can be classified as "no damage," "slight pre-damage," and "bearing defective."

[0003] The condition of a bearing can be determined by vibration measurement, which evaluates the maximum amplitude and the spectrum of shock pulses. By combining vibration measurement with measurements of bearing temperature and rotational speed, the information about the bearing condition can be further improved.

[0004] Currently, only fieldbus devices are available that offer one of the above-mentioned functions. Therefore, one device is required for vibration measurement, one for temperature measurement, and one for speed measurement. The fieldbus devices can only be operated in a control cabinet in a station and not decentrally, e.g., directly on a machine. Field devices for vibration measurement have the connection of an expensive, external piezo sensor with an IEPE interface. The evaluation of all signals, and thus the condition of the machine, takes place in a central, higher-level control system.

[0005] The document US 2016 / 290854 A1 relates to a device for analyzing the condition of a machine. The condition analysis system includes a sensor unit for generating a measured value. The measured value may depend on a movement, in particular vibrations or shock pulses caused by bearings when the shaft rotates.

[0006] The publication WO 2013 / 160053 A1 relates to a method for predicting the remaining service life of a bearing.

[0007] The document EP 0 961 918 A1 relates to the automatic prediction of a machine fault using a transducer sensor.

[0008] The document WO 98 / 01831 A1 relates to a method for evaluating the condition of a machine with a measuring point, which is carried out by a movable analysis device.

[0009] The document US 6 199 018 B1 discloses a distributed diagnostic system with a local monitoring device for a machine.

[0010] It is the object of the present invention to create a concept for improved condition monitoring, in particular for improved condition monitoring of mechanical machine components.

[0011] This object is achieved by a condition monitoring device having the features according to independent claim 1. Advantageous embodiments are the subject of the dependent claims, the description, and the drawings.

[0012] Such a condition monitoring device offers the technical advantage of determining the condition of a bearing and thus the condition of the machine or system. This allows wear and damage to be detected early and maintenance to be optimized.

[0013] In an advantageous embodiment of the condition monitoring device, the communication interface is designed to couple the condition monitoring device to the external control device via a point-to-point connection.

[0014] This provides the technical advantage that the condition monitoring device can be operated easily and clearly via the external control unit.

[0015] In an advantageous embodiment of the condition monitoring device, the communication interface is designed to supply the condition monitoring device with external DC voltage.

[0016] This provides the technical advantage that the condition monitoring device can be designed compactly, as it does not require its own power supply and a corresponding power supply or battery.

[0017] In an advantageous embodiment, the condition monitoring device comprises a DC-DC converter which is designed to convert the external DC voltage supplied via the communication interface into an internal system voltage.

[0018] This provides the technical advantage that the externally supplied supply voltage does not have to be the same as the internal system voltage. This allows for greater flexibility in the design of the condition monitoring device.

[0019] In an advantageous embodiment of the condition monitoring device, the controller is designed to operate as a slave in master-slave mode and is controllable via the communication interface.

[0020] This provides the technical advantage of allowing the use of standard master-slave architectures. The controller can be designed to be power-efficient, as it only needs to operate when requested by the master and can remain in sleep mode the rest of the time.

[0021] In an advantageous embodiment of the condition monitoring device, the communication interface comprises an IO-Link interface.

[0022] The IO-Link bus offers the advantageous possibility of screwing the device directly onto the machine in a decentralized manner and establishing the bus connection with the power supply via a single cable.

[0023] In an advantageous embodiment, the condition monitoring device comprises an IO-Link PHY module that is designed to transmit the information about the condition of the machine component to the external control device.

[0024] This provides the technical advantage of simplifying the design of the condition monitoring device because a standard component can be used as the IO-Link PHY component.

[0025] The condition monitoring device comprises a first input for connecting at least one external temperature sensor for detecting at least one temperature of the machine component, wherein the controller is configured to further determine the condition of the machine component based on measurement data of the first input.

[0026] By integrating the temperature input, the condition diagnosis is made more precise, as the temperature behavior of the machine is also taken into account in addition to the vibration behavior.

[0027] The first input comprises a plurality of RTD lines for connecting at least one external resistance temperature sensor.

[0028] This provides the technical advantage of enabling compact temperature measurement with resistance temperature sensors via the RTD lines. The entire condition monitoring device thus remains compact and can be easily attached to the machine component, e.g., a bearing.

[0029] The condition monitoring device includes an internal current source configured to drive a predetermined current through the RTD lines through the at least one external resistance temperature sensor.

[0030] This provides the technical advantage of enabling efficient and compact temperature measurement that utilizes the temperature behavior of a resistor.

[0031] The condition monitoring device includes a first analog-to-digital (A / D) converter configured to detect a voltage drop across the RTD lines and convert it to a digital value and forward it to the controller.

[0032] This provides the technical advantage that the measured voltage drop and thus the temperature value can be transmitted to the microcontroller in an efficient manner.

[0033] In an advantageous embodiment of the condition monitoring device, the controller is configured to calculate a resistance proportional to the measured temperature of the at least one resistance temperature sensor based on the voltage drop across the RTD lines and the predetermined current driven via the RTD lines.

[0034] This achieves the technical advantage that the temperature measurement can be carried out very efficiently in the microcontroller using just a few operations, so that no complex temperature sensor is required.

[0035] In an advantageous embodiment, the condition monitoring device comprises a second input for connecting at least one external speed and / or position sensor for detecting at least one speed and / or position of the machine component, and the controller is configured to further determine the condition of the machine component based on measurement data of the second input.

[0036] By integrating temperature and speed sensor inputs, all the necessary signals for optimal condition diagnostics are combined in a single device. Application costs can also be reduced.

[0037] In an advantageous embodiment, the condition monitoring device comprises at least one synchronous serial (SSI) interface, which is designed to read out measurement data of the at least one external speed and / or position sensor connected to the second input and to transmit it to the controller.

[0038] This provides the technical advantage that the measurement data on the speed and / or position of the machine component can be efficiently read in and transferred to the microcontroller.

[0039] The vibration sensor is designed as a semiconductor-based MEMS-based vibration sensor.

[0040] With a MEMS sensor integrated into the condition monitoring device, there is no longer any need to use expensive external piezo sensors that must be connected via an IEPE interface, for example. The MEMS sensor used can measure the vibration of the machine component, such as a bearing, with the required bandwidth.

[0041] In an advantageous embodiment of the condition monitoring device, the controller is designed to determine an amplitude spectrum based on the measurement data generated by the vibration sensor.

[0042] This provides the technical advantage that vibrations that occur outside the permissible range of the machine component can be easily determined using the amplitude spectrum.

[0043] In an advantageous embodiment, the condition monitoring device comprises a high-pass filter for filtering the measurement data generated by the vibration sensor; a rectifier for rectifying the high-pass filtered measurement data of the vibration sensor; and a second analog-to-digital (A / D) converter for converting the rectified high-pass filtered measurement data of the vibration sensor into digital measurement data, wherein the controller is configured to determine the amplitude spectrum based on the digital measurement data of the vibration sensor.

[0044] This provides the technical advantage that the frequency range to be scanned, in which possible malfunctions may occur, can be easily narrowed down.

[0045] In an advantageous embodiment of the condition monitoring device, the second A / D converter is integrated in the vibration sensor, and the high-pass filter is implemented as a function in the controller.

[0046] This provides the technical advantage that the condition monitoring device can be designed compactly and can therefore be easily attached to the machine component.

[0047] In an advantageous embodiment of the condition monitoring device, the communication interface comprises an M12 screw connector for connecting the external control unit and for power supply.

[0048] This provides the technical advantage of achieving a compact and robust connection that does not loosen during the operating mode of the machine component, thus achieving reliable monitoring results.

[0049] Further embodiments are explained with reference to the accompanying drawings. They show: Fig. 1 is a schematic representation of a condition monitoring device 100 for monitoring the condition of a mechanical machine component, Fig. 2 is a schematic representation of an IO-Link device 200 for condition monitoring according to a first embodiment, Fig. 3 is a schematic representation of an IO-Link device 300 for condition monitoring according to a second embodiment, and Fig. 4 is a schematic representation of a method 400 for monitoring the condition of a mechanical machine component.

[0050] The following describes IO-Link systems and IO-Link devices or measuring devices with IO-Link interface.

[0051] IO-Link is a serial, bidirectional point-to-point connection for signal transmission and power supply below any network, fieldbus or backplane bus.

[0052] An IO-Link system consists of IO-Link devices, usually sensors, actuators, or combinations thereof, as well as a standard 3-wire sensor / actuator cable and an IO-Link master. The master can be a device of any design and protection class.

[0053] The IO-Link master establishes the connection between the IO-Link devices and the automation system. As part of a peripheral system, the IO-Link master is installed, for example, either in the control cabinet or as a remote I / O directly in the field. The IO-Link master communicates via various fieldbuses or product-specific backplane buses. An IO-Link master can have multiple IO-Link ports (channels). An IO-Link device can be connected to each port (via point-to-point communication). IO-Link is therefore a point-to-point communication system.

[0054] M12 connectors are defined for connection technology in IP65 / 67, with sensors typically having a 4-pin connector and actuators a 5-pin connector. IO-Link masters generally have a 5-pin M12 socket.

[0055] According to IEC 60974-5-2, the pin assignment is specified as follows: Pin 1: 24 V; Pin 3: 0 V; Pin 4: switching and communication line (C / Q). These three pins provide not only IO-Link communication but also power the device with a maximum of 200 mA.

[0056] Measuring devices with SPI and UART interfaces are described below. The Serial Peripheral Interface (SPI for short) is a bus system for a synchronous serial data bus with which digital circuits can be connected according to the master-slave principle. A UART interface is used to send and receive data over a data line and forms the standard for serial interfaces on PCs, microcontrollers, and in industrial applications. The data is transmitted as a serial digital data stream with a fixed frame consisting of a start bit, five to a maximum of nine data bits, an optional parity bit for detecting transmission errors, and a stop bit.

[0057] The devices described below include communication interfaces that operate according to the master-slave principle. Master-slave, or main computer-satellite computer, is a hierarchical concept for the organization and distribution of tasks between higher-level stations – in this case, the master stations – and subordinate processing units, the slaves. Such concepts are used whenever one processing unit takes over control and task distribution from another.

[0058] The master-slave concept is implemented in client-server architectures, fieldbuses, and Bluetooth, among other applications. In the client-server principle, the server operates as a master station, equipped with its own operating system, higher intelligence, and a wider range of functions than the clients. The clients, acting as slave stations, are passive communication participants that are requested by the master station to receive or send data.

[0059] The following describes MEMS sensors, particularly MEMS vibration sensors. MEMS (Micro-Electro-Mechanical Systems) are tiny components that combine logic elements and micromechanical structures in a single chip. They can process mechanical and electrical information. MEMS elements are used in sensors, actuators, oscillators, and filters. These mechatronic chips are usually made of silicon. The structures can be smaller than a micrometer. Due to their miniaturization, they can be manufactured cheaply and in mass quantities, just like semiconductors. MEMS vibration sensors are designed to measure vibrations or mechanical oscillations.

[0060] Fig. 1shows a schematic representation of a condition monitoring device 100 for monitoring the condition of a mechanical machine component. The condition monitoring device 100 includes a vibration sensor 110, a controller 101, and a wired communication interface 120.

[0061] The vibration sensor 110 is used to detect mechanical vibrations on the machine component. The controller 101 is coupled to the vibration sensor 110 and configured to determine a state of the machine component based on measurement data 116 generated by the vibration sensor 110. The communication interface 120 is communicatively coupled to the controller 101 and configured to communicate with an external control unit. The controller 101 is configured to transmit the requested information via the wired communication interface 120 based on a request for transmission of information about the state of the machine component.

[0062] The communication interface 120 can, for example, be configured to couple the condition monitoring device 100 to the external control unit via a point-to-point connection. The communication interface 120 can be configured to supply the condition monitoring device with external DC voltage.

[0063] The controller 101 can operate as a slave in master-slave mode and can be controlled via the communication interface 120.

[0064] The communication interface 120 may comprise an IO-Link interface, such as in the Figures 2 and 3 described.

[0065] The condition monitoring device 100 may include an IO-Link PHY module 121, such as shown in the Figures 2 and 3 shown, which is designed to transmit the information about the state of the machine component to the external control unit.

[0066] In one embodiment, the condition monitoring device 100 comprises a DC-DC converter 123, which is designed to convert the external DC voltage supplied via the communication interface 120 into an internal system voltage 124, for example as shown in Figure 2 or 3 .

[0067] In one embodiment, the condition monitoring device 100 may comprise a first input 140 for connecting at least one external temperature sensor for detecting at least one temperature of the machine component, as shown, for example, in the Figures 2 and 3 The controller 101 may be configured to determine the state of the machine component further based on measurement data 146 of the first input 140, such as in the Figures 2 and 3 described.

[0068] The first input 140 may include a plurality of RTD lines for connecting at least one external resistance temperature sensor. The condition monitoring device 100 may further include an internal power source 142, such as shown in FIGS. Figures 2 and 3 configured to drive a predetermined current through the RTD lines through the at least one external resistance temperature sensor. The condition monitoring device 100 may further include a first analog-to-digital (A / D) converter 143, such as shown in the Figures 2 and 3shown, which is configured to detect a voltage drop across the RTD lines and to forward it as a converted digital value to the controller 101. The controller 101 can be configured to calculate a resistance proportional to the measured temperature of the at least one resistance temperature sensor based on the voltage drop across the RTD lines and the predetermined current driven via the RTD lines.

[0069] The condition monitoring device 100 may further comprise a second input 130 for connecting at least one external speed and / or position sensor for detecting at least one speed and / or position of the machine component, as shown, for example, in the Figures 2 and 3The controller 101 may be configured to determine the state of the machine component further based on measurement data 136 of the second input 130. The condition monitoring device 100 may further comprise at least one synchronous serial (SSI) interface 132, as shown, for example, in the Figures 2 and 3 which is designed to read out the measurement data 136 of the at least one external speed and / or position sensor connected to the second input 130 and to transmit it to the controller 101.

[0070] The vibration sensor 110 can, for example, be implemented as a semiconductor-based MEMS-based vibration sensor.

[0071] The controller 101 may be configured to determine an amplitude spectrum based on the measurement data 116 generated by the vibration sensor 110, for example using a frequency transformation such as a DFT or FFT.

[0072] In one embodiment, the condition monitoring device 100 may include a high-pass filter 111 for filtering the measurement data 116 generated by the vibration sensor 110, a rectifier 112 for rectifying the high-pass filtered measurement data of the vibration sensor 110; and a second analog-to-digital (A / D) converter 113 for converting the rectified high-pass filtered measurement data of the vibration sensor 110 into digital measurement data, such as in the Figures 2 and 3 The controller 101 can be configured to determine the amplitude spectrum based on the digital measurement data of the vibration sensor 110.

[0073] In one embodiment, the second A / D converter 113 may be integrated in the vibration sensor 110, such as in Figure 3 The high-pass filter 111 can be implemented as a function in the controller 101, for example as a DSP (Digital Signal Processing) function.

[0074] In one embodiment, the communication interface 120 may comprise an M12 screw connector 122 for connecting the external control unit and for supplying power, as shown, for example, in the Figures 2 and 3 shown.

[0075] Fig. 2 shows a schematic representation of an IO-Link device 200 for condition monitoring according to a first embodiment.

[0076] The IO-Link device 200 is a special embodiment of the above-mentioned Figure 1 described condition monitoring device 100. The IO-Link device 200 comprises a vibration sensor 110, a controller 101 and an IO-Link interface 120.

[0077] The vibration sensor 110 is used to detect mechanical vibrations on the machine component. The controller 101 is coupled to the vibration sensor 110 and configured to determine a state of the machine component based on measurement data 116 generated by the vibration sensor 110. The IO-Link interface 120 is communicatively coupled to the controller 101 and configured to communicate with an external control unit, for example, an IO-Link master. The controller 101 is configured to transmit the requested information to the external control unit via the wired communication interface 120 based on a request from the external control unit for transmitting information about the state of the machine component.

[0078] The IO-Link device 200 includes an IO-Link PHY module that implements communication with the IO-Link master at the physical level and transmits data from the IO-Link device 200 acting as a slave to the control unit acting as the master. The communication interface includes an M12 screw connector 122, to which a cable can be screwed to connect the IO-Link device 200 to the control unit. The supply voltage of the IO-Link device 200 is transmitted via the IO-Link 120. This supply voltage can be converted into the system voltage of the IO-Link device 200, e.g., 3.3 V, in a DC / DC component.

[0079] The vibration sensor 110 is designed as a MEMS vibration sensor and is coupled to an SPI interface of the microcontroller 101 via a high-pass filter 111, a rectifier 112 and an analog-to-digital converter 113.

[0080] A first input 140 is used to connect one or more temperature sensors, e.g., resistance thermometers, via an M8 screw connector 141. A current source 142 supplies a predefined current to power the temperature sensor(s). The resulting temperature-dependent voltage change is recorded by a second analog-to-digital converter 143 and converted into a digital measured value, which is transmitted to an SPI interface 144 of the microcontroller 101.

[0081] A second input 130 is used to connect one or more speed and / or position sensors via an M8 screw connector 131. The measured values ​​136 of these sensors are read out by an SSI interface 132 and made available to the microprocessor.

[0082] In the Figure 2The IO-Link device 200 shown combines the above-mentioned functions such as vibration, temperature, and speed measurement in a single device. The evaluation of the measured signals also takes place in the device. The sensor / actuator bus standard IO-Link is selected as the bus system. A 24V power supply is also carried via the IO-Link cable 120, which serves as the power supply for the device 200. The device 200 is connected with just one cable and can therefore be screwed directly to the machine in a decentralized manner. In addition to the condition of the bearing, measured values ​​such as the spectrum and amplitude of the vibration, as well as bearing temperature and speed, can be transmitted via the bus 120. Based on the bearing data parameterized by the user, such as speed and maximum bearing temperature, the condition of the bearing and the remaining service life are calculated by the microcontroller 101 in the device 200. In addition to using just one device, the user also saves on an expensive, external piezo vibration sensor.

[0083] Device 200 is designed as an IO-Link slave (device) and is connected to the IO-Link master via the standardized M12 screw connector 122. In addition to the bus signals, the IO-Link cable 120 also carries a 24V operating voltage that supplies device 200. An integrated DC / DC converter 123 in device 200 generates the 3.3V system voltage 124 from the 24V. The data is transmitted from slave 200 to the master via the IO-Link Phy 121.

[0084] The device 200 has an integrated MEMS-based (semiconductor-based) vibration sensor 110. For optimal evaluation of the spectrum and amplitude of the vibration, the analog sensor signals 116 are first discretely high-pass filtered 111, rectified 112, and recorded with an analog / digital converter 113. The measured values ​​are transmitted from the ADC 113 to the microcontroller 101 via an SPI interface 114.

[0085] Alternatively, the ADC 113 may be integrated in the vibration sensor 110, as in the second embodiment of the IO-Link device 300 in Figure 3 The data is transmitted to the microcontroller 101 via an SPI interface 114. The high-pass filter 111 is implemented in the microcontroller 101 with a DSP function, as shown in Figure 3 In the microcontroller 101, an amplitude spectrum is calculated from the time-discrete measured values ​​using FFT (Fast Fourier Transformation).

[0086] Temperature sensors, e.g., PT100, can be connected to the two or more RTD temperature inputs 140 using M8 screw connectors 141. The electrical resistance of the sensor is proportional to the temperature. Internal current sources 142 drive a defined current through the temperature sensor. The voltage drop across the sensor, measured by an analog / digital converter 143, is transmitted to the microcontroller 101 via an SPI interface 144. In the microcontroller 101, the resistance proportional to the temperature is calculated using the voltage drop and the driven current.

[0087] Speed ​​or position sensors can be connected to one or more SSI interfaces 132. The data is transmitted from the sensor via the hardware driver to the microcontroller 101, where it is evaluated.

[0088] Microcontroller 101 records the individual sensor signals and uses them to calculate the bearing temperature, speed, vibration amplitude and spectrum, and bearing condition. Microcontroller 101 is connected to the IO-Link PHY 121 via a UART interface, contains the IO-Link stack, and establishes communication with the master for data transmission.

[0089] Fig. 3 shows a schematic representation of an IO-Link device 300 for condition monitoring according to a second embodiment.

[0090] The IO-Link device 300 is a special embodiment of the above-mentioned Figure 1 The IO-Link device 300 corresponds to the Figure 2 described IO-Link 200, wherein the analog-digital converter 113 is integrated in the MEMS vibration sensor 110 and the high-pass filter 111 is implemented as a function, e.g. DSP function, in the microcontroller 101.

[0091] Figures 2 and3 thus each show an IO-Link device 200, 300 with M12 screw connector 122 for bus connection and power supply; an integrated DC / DC converter 123 for generating the internal system voltage; an integrated microcontroller 101 for signal processing and signal evaluation and bus communication; an integrated MEMS-based vibration sensor 110 for vibration measurement (amplitude and spectrum); RTD inputs 140 for connecting external temperature sensors with M8 screw connectors 141; and SSI inputs 130 for connecting external speed and position sensors with M8 screw connectors 131.

[0092] Fig. 4 shows a schematic representation of a method 400 for monitoring the condition of a mechanical machine component.

[0093] The method 400 comprises the following steps: detecting 401 mechanical vibrations on a machine component by a vibration sensor; determining 402 a state of the machine component based on measurement data generated by the vibration sensor; and transmitting 403 information about the state of the machine component via a wired communication interface based on a request to transmit the information.

[0094] The method 400 can be implemented, for example, in a condition monitoring device 100 or an IO-Link device 200, 300, as described above for the Figures 1 to 3 described, can be realized. LIST OF REFERENCE SYMBOLS

[0095] 100Condition monitoring device 101Controller, microcontroller 110Vibration sensor, MEMS vibration sensor 111High-pass filter 112Rectifier 113Analog-to-digital converter 114SPI interface 116Measurement data of the vibration sensor 120Communication interface, wired, IO-Link bus to the master 121IO-Link PHY 122M12 screw connector 130Second input 131M8 screw connector 132SSI interface 136Measurement data of the second input 140First input 141M8 screw connector 142Current source 143Analog-to-digital converter 144SPI interface 146Measurement data of the first input 200IO-Link device according to the first embodiment 300IO-Link device according to the second embodiment 400Method for monitoring the condition of a mechanical machine component 401First step: Detecting 402Second step: Determining 403Third step: Transmitting

Claims

1. State monitoring device (100, 200, 300) for monitoring the state of a mechanical machine component, comprising: a vibration sensor (110) for detecting mechanical vibrations at the machine component, wherein the vibration sensor (110) is configured as a MEMS-based vibration sensor on a semiconductor basis; a controller (101), which is coupled to the vibration sensor (110) and is configured to determine a state of the machine component based on measurement data (116) generated by the vibration sensor (110); and a wired communication interface (120) coupled to the controller (101) by communication technology for communication with an external control device, wherein the controller (101) 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 (120), wherein the state monitoring device has a first input (140) for connecting at least one external resistance temperature sensor for detecting at least one temperature of the machine component, wherein the first input (140) 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 (142), 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 (143), which is configured to detect a voltage drop across the RTD lines and to forward it as a converted digital value to the controller (101), wherein the controller (101) is configured to determine the state of the machine component further based on measurement data (146) of the first input (140).

2. State monitoring device (100, 200, 300) according to claim 1, wherein the communication interface (120) is configured to couple the state monitoring device (100, 200, 300) to the external control device via a point-to-point connection.

3. State monitoring device (100, 200, 300) according to claim 1 or 2, wherein the communication interface (120) is configured to supply the state monitoring device (100, 200, 300) with external DC voltage.

4. State monitoring device (200, 300) according to claim 3, comprising: a DC-DC converter (123), which is configured to convert the external DC voltage supplied via the communication interface (120) into an internal system voltage (124).

5. State monitoring device (100, 200, 300) according to one of the preceding claims, wherein the controller (101) is configured to operate as a slave in master-slave mode and is controllable via the communication interface (120).

6. State monitoring device (200, 300) according to one of the preceding claims, wherein the communication interface (120) comprises an IO-Linkinterface.

7. State monitoring device (200, 300) according to claim 6, comprising: an IO-LinkPHY module (121), which is configured to transmit the information about the state of the machine component to the external control device.

8. State monitoring device (200, 300) according to one of the preceding claims, wherein the controller (101) is configured to calculate a resistance proportional to the measured temperature of the at least one resistance temperature sensor based on the voltage drop across the RTD lines and the predetermined current driven via the RTD lines.

9. State monitoring device (200, 300) according to one of the preceding claims, comprising a second input (130) for connecting at least one external speed and / or position sensor for detecting at least one speed and / or position of the machine component, wherein the controller (101) is configured to determine the state of the machine component further based on measurement data (136) of the second input (130).

10. State monitoring device (200, 300) according to claim 9, comprising at least one synchronous serial (SSI) interface (132), which is configured to read out the measurement data (136) of the at least one external speed and / or position sensor connected to the second input (130) and to transmit it to the controller (101).

11. State monitoring device (100, 200, 300) according to one of the preceding claims, wherein the controller (101) is configured to determine an amplitude spectrum based on the measurement data (116) generated by the vibration sensor (110).

12. State monitoring device (200, 300) according to claim 11, comprising: a high-pass filter (111) for filtering the measurement data (116) generated by the vibration sensor (110); a rectifier (112) for rectifying the high-pass filtered measurement data of the vibration sensor (110); and a second analog-digital (A / D) converter (113) for converting the rectified high-pass filtered measurement data of the vibration sensor (110) into digital measurement data, wherein the controller (101) is configured to determine the amplitude spectrum based on the digital measurement data of the vibration sensor (110).

13. State monitoring device (300) according to claim 12, wherein the second A / D converter (113) is integrated in the vibration sensor (110), and wherein the high-pass filter (111) is implemented as a function in the controller (101).

14. State monitoring device (200, 300) according to one of the preceding claims, wherein the communication interface (120) comprises an M12 screw connector (122) for connecting the external control device and for supplying power.