AUTOMATION FIELD DEVICE

Abstract

Disclosed is an automation field device, comprising a sensor unit for registering a physical, measured variable of a medium; a first communication interface for connecting to a first communication network; a second communication interface for connecting to a second communication network; a first electronics unit embodied to convert the physical, measured variable registered by the sensor unit into a measured value, to provide the measured value via the first communication interface to the first communication network and to generate diagnostic- and/or maintenance information; a transmitting unit contained in the first electronics unit and embodied to transmit the diagnostic- and/or maintenance information generated by the first electronics unit; a second electronics unit including a receiving unit embodied to receive the diagnostic- and/or maintenance information transmitted by the transmitting unit embodied to provide the diagnostic- and/or maintenance information via the second communication interface to the second communication network.

Claims

1-7. (canceled)

8. An automation field device, comprising: a sensor unit for registering a physical, measured variable of a medium; a first communication interface for connecting to a first communication network; a second communication interface for connecting to a second communication network; a first electronics unit embodied to convert the physical, measured variable registered by the sensor unit into a measured value, to provide the measured value via the first communication interface to the first communication network, and to generate diagnostic- and/or maintenance information; a transmitting unit contained in the first electronics unit and embodied to transmit the diagnostic- and/or maintenance information generated by the first electronics unit; a second electronics unit including a receiving unit embodied to receive the diagnostic- and/or maintenance information transmitted by the transmitting unit and further embodied to provide the diagnostic- and/or maintenance information via the second communication interface to the second communication network.

9. The field device as claimed in claim 8, wherein the transmitting unit is an acoustic output source embodied to transmit the diagnostic- and/or maintenance information via modulated sound waves.

10. The field device as claimed in claim 9, wherein the receiving unit is an acoustic receiving source embodied to receive the sound waves transmitted by the transmitting unit, to demodulate the received sound waves, and to provide the demodulated, received sound waves to the second electronics unit.

11. The field device as claimed in claim 8, wherein the transmitting unit is a light source embodied to transmit the diagnostic- and/or maintenance information via modulated electromagnetic radiation.

12. The field device as claimed in claim 11, wherein the receiving unit is a light sensor embodied to receive the electromagnetic radiation transmitted by the transmitting unit, to demodulate the received electromagnetic radiation, and to provide the demodulated, received electromagnetic radiation to the second electronics unit.

13. The field device as claimed in claim 8, wherein the first communication interface is an interface for connecting to an electrical current loop or to a HART-modulated electrical current loop.

14. The field device as claimed in claim 8, wherein the second communication interface is an interface for connecting to an automation fieldbus.

Description

[0026] The invention will now be explained in greater detail based on the appended drawing, the sole FIGURE of which shows as follows:

[0027] FIG. 1 a first example of an embodiment of the field device of the invention.

[0028] FIG. 1 shows a field device FD of the invention. The field device FD is installed at a measuring point of an automated plant and serves for determining a physical, measured variable of a process medium. For registering the physical, measured variable, the field device FD includes a sensor unit SU. For example, the sensor unit SU is a radar unit and serves for the contactless measuring of a fill level of a medium in a container. Other examples of such sensor units SU and possible applications for the field device FD have already been listed, by way of example, in the introductory portion of the description.

[0029] For transforming/further processing of the registered measured variable and for controlling the measuring process, the field device FD includes a first electronics unit EL1, for example, in the form of a microcontroller or an ASIC. The registered measured variable is processed by the first electronics unit EL1 into a measured value and provided to a first communication interface KI1. A first communication network KN1 is connected to the first communication interface KI1. The first communication network is an electrical current loop, which uses 4-20 mA technology. As a function of size of the measured value, analogously an electrical current value between 4 mA and 20 mA is output via the electrical current loop. Since the electrical current loop works purely in an analog manner, the field device cannot be serviced via the first communication interface KI1. A hacking of the field device FD via connecting of an unauthorized person with the first communication network KN1 is, consequently, not possible.

[0030] Besides the above described functions, the first electronics unit EU serves for control of the functions of the field device FD, for parameter administration of the field device FD and for creating diagnostic- and/or maintenance information of the field device FD. The diagnostic- and/or maintenance information (“function in order”, “maintenance required”, “case of malfunction”, etc.) is created, for example, according to the NAMUR recommendation and represents the device status of the field device FD.

[0031] This diagnostic- and/maintenance information is not transmittable via the first communication network KN1, since this is embodied only for analog transmission of the measured values of the field device FD. For digital transmission of the diagnostic- and/or maintenance information, the field device FD includes a second communication interface KI2. This second communication interface KI2 is embodied for connecting to an automation fieldbus, which enables a digital transmission of information. Such a fieldbus is based on one of the established protocols, for example, one of the protocols, HART, Profibus PA/DP, Foundation Fieldbus, etc.

[0032] A direct connection of the first electronics unit EL1 with the second communication interface KI2 introduces the risk that an unauthorized person could obtain access to sensitive information of the field device FD, for example, by means of triggering a buffer overflow in the communication stack of the field device FD, especially when the second communication network KN2 is connected with the Internet.

[0033] In view of this, the second communication interface KI2 is not directly connected with the first electronics unit EL1. The field device FD is embodied in such a manner that it has a second electronics unit EL2, which is connected with the second communication interface KI2. The second electronics unit serves for control of the second communication interface KI2 and for transmission of the information to be transmitted from the second communication interface.

[0034] The transmission of the diagnostic- and/or maintenance information from the first electronics unit EL1 to the second electronics unit EL2 occurs by means of a unidirectional transmission path. To this end, the first electronics unit EL1 includes a transmitting unit ST and the second electronics unit EL2 includes a receiving unit RT.

[0035] The transmitting unit ST is, for example, a loudspeaker, which transmits the diagnostic- and/or maintenance information by means of frequency modulated sound waves. The second electronics unit EL2 receives the diagnostic- and/or maintenance information by means of a microphone and provides the diagnostic- and/or maintenance information to the second communication interface KI2.

[0036] Alternatively, it is provided that the transmitting unit is a light emitting diode, which transmits the diagnostic- and/or maintenance information by means of frequency- and/or phase modulated, electromagnetic radiation. The second electronics unit EL2 receives the diagnostic- and/or maintenance information by means of a light sensor and provides the diagnostic- and/or maintenance information to the second communication interface KI2.

[0037] In this way, an exclusively unidirectional data transmission from the first electronics unit EL1 to the second electronics unit EL2 is enabled. Even when an unauthorized person would obtain access via the second communication network KN2 to the second electronics unit, the person could not obtain access to the sensitive data of the field device FD administered by the first electronics unit EL1.

[0038] The example of an embodiment shown in FIG. 1 is purely by way of example. The invention includes other possible combinations of type of field device, types of first and second communication networks KN1, KN2 and types of receiving- and transmitting units ST, RT.

LIST OF REFERENCE CHARACTERS

[0039] RT receiving unit [0040] FD field device [0041] SU sensor unit [0042] EL1, EL2 electronic units [0043] KN1, KN2 communication networks [0044] KI1, KI2 communication interfaces [0045] ST transmitting unit