Electronic module for a pressure gauge and method for operating an electronic module

Abstract

The invention relates to an electronic module (100) for a pressure gauge (1), comprising: - a first pressure sensor (3), a second pressure sensor (16), an evaluation unit (17) having an evaluation input (17a) and an evaluation output (17b), a main electronics system (28) having a data input (28a) and a data output (28b), and a control unit (40) having a control module (41) and a switch (42), wherein the control module (41) has a control input (41a) and a control output (41b), - a first communication line (50) which interconnects the data output (28b), the evaluation input (17a) and the control input (41a), - a second communication line (51) which interconnects the data input (28a), the evaluation output (17b), the control output (41b) and the switch (42), - a third communication line (52) which connects the control unit (40) to the second pressure sensor (16).

Description

[0001] Electronic module for a pressure sensor and method for operating a

[0002] electronic module

[0003] The invention relates to an electronic module for a pressure sensor and a method for operating an electronic module.

[0004] In pressure measurement technology, absolute pressure, differential pressure, and gauge pressure sensors are known. Absolute pressure sensors determine the prevailing pressure of a process medium absolutely, i.e., relative to a vacuum, while differential pressure sensors determine the difference between two different pressures of the process medium or media. With gauge pressure sensors, the pressure of the process medium to be measured is determined relative to a reference pressure, where the prevailing atmospheric pressure in the vicinity of the gauge serves as the reference pressure.

[0005] Pressure sensors have a pressure-sensitive measuring element, the so-called pressure sensor, on whose first and second surfaces pressure is applied. In the case of relative or absolute pressure sensors, the pressure of the process medium to be measured acts on the first surface of the pressure sensor, while an absolute or reference pressure acts on the second surface. In the case of differential pressure sensors, a first and a second pressure of the process medium are applied to each surface. The measuring element bends depending on the relative pressure, which is formed by the difference between the pressures applied to the two surfaces. This bending is converted by an electronic unit into an electrical signal dependent on the relative pressure, which is then available for further processing or evaluation. A distinction is made, among other things, between capacitive and piezoresistive pressure sensors.A large number of such pressure sensors are manufactured and distributed by companies of the Endress+Hauser Group.

[0006] A ceramic pressure sensor, for example, comprises a ceramic base and a ceramic measuring diaphragm, which is pressure-tightly bonded to the base using an active brazing alloy to form a measuring chamber. Silicon chips, typically bonded to a silicon substrate, are also known as pressure sensors. Furthermore, the pressure sensor usually includes a transducer for converting pressure-dependent deformation of the measuring diaphragm into a primary electrical signal, as well as a primary signal path extending through the base. The transducer can be, for example, a capacitive or a resistive transducer. The primary signal path usually includes at least one electrical feedthrough through the base.

[0007] In the case of absolute and relative pressure sensors, the pressure of the medium is measured by means of one, and in the case of differential pressure sensors, by means of two, pressure-sensitive diaphragms facing the process. Each diaphragm has an associated diaphragm bed, which typically serves to emboss the diaphragm and to limit its movement in case of overload. Additionally, a pressure transmission medium is used, which transmits the pressure of the medium acting on the diaphragm to one of the two surfaces of the pressure sensor via a pressure transmission path. The diaphragm is usually mounted on a process adapter.

[0008] If the diaphragm breaks or is damaged, the medium can penetrate the pressure sensor and contaminate and / or even damage it. To prevent this, German patent application DE 199 49 831 B4 discloses the use of a diaphragm system consisting of two parallel diaphragms, one facing the medium and the other facing the pressure fluid. A vacuum-sealed space is provided between the two diaphragms. A detection device monitors any changes in the vacuum within this space.

[0009] Such a detection device can be designed as a capacitive sensor. Mechanical pressure switches or mechanically operated drag pointers with switching contacts or pressure transmitters are also common.

[0010] The requirements for a vacuum sensor intended for use as a detection device are, firstly, the monitoring of the vacuum between the two membranes and, secondly, the ability to withstand potentially high process pressures in the event of a leak. Such vacuum sensors are not currently available on the market.

[0011] Furthermore, it remains unresolved how the vacuum can be monitored without fundamentally redesigning the existing electronic circuitry, let alone negatively impacting its safety and communication capabilities. For example, communication with the actual pressure sensor must not be slowed down under any circumstances. Likewise, it must be ensured that the existing electronics continue to reliably detect communication errors.

[0012] It is therefore an object of the invention to propose an electronic module which enables simple and safe monitoring of the vacuum without negatively affecting the existing electronic circuit in terms of safety and communication technology.

[0013] This problem is solved according to the invention by an electronic module for a pressure sensor according to claim 1.

[0014] The electronic module according to the invention comprises: a first pressure sensor, a second pressure sensor, an evaluation unit with an evaluation input and an evaluation output, a main electronics unit with a data input and a data output, a control unit with a control module and a switch, wherein the control module has a control input and a control output, a first communication line which connects the data output, the evaluation input and the control input, a second communication line which connects the data input, the evaluation output, the control output and the switch, a third communication line which connects the control unit to the second pressure sensor.

[0015] The electronic module according to the invention enables the integration of a second pressure sensor and / or further sensors into the existing electronic circuit without requiring fundamental modifications to the existing electronics. Thanks to the connection of the second pressure sensor via the control unit, it can communicate with the main electronics using existing communication lines. Furthermore, the existing communication between the first pressure sensor and the main electronics is not negatively affected by the additional communication with the second pressure sensor; that is, it is not delayed or compromised. Even a faulty collision in the communication between the first and second pressure sensors is clearly detected by the main electronics.Thanks to the control unit 40 according to the invention, it is not necessary to intercept the first pressure signal from the first pressure sensor and retransmit it, which would represent a potential source of error. Instead, it is possible to send the first pressure signal directly to the main electronics via the diverter valve. This ensures that the existing electronic circuit is not negatively affected in terms of safety or communication. Furthermore, integrating the second pressure sensor is easily accomplished, as existing communication lines are also used by the second pressure sensor.

[0016] According to one embodiment of the invention, the switch comprises a logic gate.

[0017] According to one embodiment of the invention, the switch is a switch and has a first switch position and a second switch position, wherein the switch can be switched between the first switch position and the second switch position by the control module.

[0018] According to a further embodiment of the invention, the third communication line comprises a l 2 C-Bus.

[0019] According to one embodiment of the invention, the evaluation unit has a first address in a first address range, and the control unit has a second address in a second address range outside the first address range. The aforementioned problem is also solved by a method for operating an electronic module for a pressure sensor according to claim 6.

[0020] The method according to the invention comprises:

[0021] Providing an electronic module according to the invention,

[0022] Transmission of a first pressure signal from the first pressure sensor from the evaluation output of the evaluation unit to the data input of the main electronics via the second communication line, wherein the first pressure signal has a plurality of pressure values ​​with a first repetition frequency and a first signal duration and between each pressure value a data pause with a data pause duration,

[0023] Sending a pressure query from the data output of the main electronics to the control input of the control unit via the first communication line,

[0024] Reading a second pressure signal from the second pressure sensor by the control unit via the third communication line,

[0025] Transmission of the second pressure signal from the control unit to the data input of the main electronics via the second communication line during a data pause of the first pressure signal.

[0026] According to one embodiment of the invention, the switch is a toggle switch and the toggle switch is in its first position when the first pressure signal is transmitted, and the toggle switch is in its second position when the second pressure signal is transmitted.

[0027] According to one embodiment of the invention, the reading step comprises requesting the second pressure signal from the control unit to the second pressure sensor and transmitting the second pressure signal from the second pressure sensor to the control unit.

[0028] According to one embodiment of the invention, the step of sending a pressure query is carried out according to a second repetition frequency, preferably less than 10 Hz.

[0029] According to one embodiment of the invention, the main electronics issue an error message when the first pressure signal collides with the second pressure signal.

[0030] According to one embodiment of the invention, the main electronics output a maintenance prediction based on the second pressure signal.

[0031] The invention is explained in more detail with reference to the following description of figures. The figures show:

[0032] Fig. 1 : a first embodiment of the pressure sensor according to the invention,

[0033] Fig. 2: an embodiment of the diaphragm system of the pressure sensor from Figure 1, Fig. 3: an embodiment of the sensor unit of the second pressure sensor, Fig. 4: a schematic representation of the electronic module according to the invention,

[0034] Fig. 5: a schematic representation of the inventive method for operating the electronic module.

[0035] Figure 1 shows a schematic embodiment of a pressure sensor 1 according to the invention. The pressure sensor 1 comprises a measuring unit 2, a process adapter 6, and a sensor unit 14. A first pressure sensor 3 is arranged in the measuring unit 2. This sensor can be subjected to the first pressure p1 of the medium 24 on a first surface 4 and to a second pressure on a second surface 5, in particular opposite the first surface 4. The second pressure can be ambient pressure, absolute pressure, or another pressure of the medium 24. The pressure sensor 3 can be connected to a main electronics unit 28, which determines the first pressure p1 based on a measured value generated by the pressure sensor 3. The main electronics unit 28 can be connected to a display unit 29, which can be configured to display the first pressure p1.

[0036] The process adapter 6 has a membrane system 7, which is arranged on the medium side and shown in detail in Fig. 2. The membrane system 7 comprises a first separating membrane 8 and a second separating membrane 9, which are arranged relative to each other such that the first separating membrane 8 faces the medium 24 and the second separating membrane 9 faces away from the medium 24, and a first intermediate space 10 is enclosed between the first separating membrane 8 and the second separating membrane 9. The first intermediate space 10 is evacuated or has a vacuum. The first separating membrane 8 can be pressurized to the first pressure p1. The first separating membrane 8 and the second separating membrane 9 are each pressure-tightly attached to a circumferential edge 11a, 11b on the process adapter 6, so that a pressure chamber 12 is formed between the second separating membrane 9 and the process adapter 6. A membrane bed 26 can be associated with the second separating membrane 9.

[0037] The membrane system 7 is configured to transmit the initial pressure p1 to the pressure chamber 12. The process adapter 6 can include a section of the pressure transmission path 13, which is fluidically connected to the pressure chamber 12. The pressure transmission path 13 can be configured to transmit the initial pressure p1 from the pressure chamber 12 to the first surface 4. A further section of the pressure transmission path 13 can also be arranged in the measuring device 3.

[0038] The sensor unit 14 comprises a carrier 15, a second pressure sensor 16, and an evaluation unit 17, as shown by way of example in Fig. 3. The sensor unit 14 can be arranged on the first space 10 or on a second space 18 of the pressure transducer that is fluidically connected to the first space. The sensor unit 14 is pressure-tightly attached to the pressure transducer 1 by means of the carrier. For example, the sensor unit 14 can be arranged on the process adapter 6 and connected to the first space 10. The second pressure sensor 16 and the control unit 40 are electrically connected to each other. The second pressure sensor 16 is configured to monitor the vacuum in the first space 10.

[0039] Figure 3 shows the printed circuit board 19, which has one or more contact surfaces 32. The second pressure sensor 16 is electrically and, in particular, mechanically connected to the printed circuit board 19 by means of at least one of the contact surfaces 32, for example, by means of a solder joint. The carrier 15 is designed as a current feedthrough by way of example. The current feedthrough can have a base plate 34 and one or more connection pins 20. The printed circuit board 19 can be electrically connected to the carrier 15. The carrier 15 can be connected to the pressure sensor 1 by means of a pressure-tight weld. For example, the base plate 34 can be pressure-tightly welded to the pressure sensor 1.

[0040] The second pressure sensor 16 and / or the control unit 40 can be configured to output a loss of vacuum and / or an error signal in the event of a leakage of the first separating membrane 8. The control unit 40 is electrically connected to the main electronics 28 via the first communication line 50 and the second communication line 51. The control unit 40 is configured to transmit a measured value from the second pressure sensor 16 to the main electronics 28. The main electronics 28 can be configured to detect a leakage based on the measured value transmitted by the control unit 40 and, in particular, to transmit a warning about the leakage to the display unit 29 and / or to a customer interface, such as 4..20, HART, APL, etc. The customer interface is preferably always activated simultaneously with the display unit 29. The display unit 29 can be configured to display the warning about the leakage.The main electronics 28 can also be designed to detect a leakage based on an error signal from the control unit 40 or the second pressure sensor 16, and in particular to send a warning about the leakage to the display unit 29.

[0041] The pressure sensor 1 can have a pressure transmitter 21 with a cylindrical base body 21a and the pressure transmission path 13 arranged therein, which can be filled with a pressure transmission fluid. The pressure transmitter 21 can be arranged between the measuring unit 2 and the process adapter 6.

[0042] The pressure sensor 1 can further comprise a sleeve 22. The sleeve 22 surrounds the pressure transmitter 21, at least partially, such that a second space 18 is formed between an outer wall 21b of the pressure transmitter 21 and an inner wall 22a of the sleeve 22. The sleeve 22 can surround the pressure transmitter 21 from its first end region 30 to its second end region 31. The sleeve 22 can be pressure-tightly connected to both the process adapter 6 and the pressure transmitter 21, in particular by means of a weld, especially an orbital weld. The weld points are shown as black, round dots (see Figure 2).

[0043] The second space 18 is arranged, in particular, coaxially with the pressure transmission path 13. The second space 18 can be arranged such that it surrounds the pressure transmission path 13. The base body 21a of the pressure transmitter 21 can be cylindrical. The inner wall 22a of the sleeve 22 can be cylindrical. The second space 18 can essentially be in the form of a hollow cylinder.

[0044] The process adapter 6 can have a channel 23, which is arranged and configured such that the channel 23 fluidically connects the first intermediate space 10 with the second intermediate space 18. The channel 23 can lead from a region between the circumferential edges 11a, 11b of the first separating membrane 8 and the second separating membrane 9 to an end face 6a of the process adapter facing the pressure transmitter 21. As shown by way of example in Fig. 1, the channel 23 can initially have a section arranged perpendicular to the end face 6a in the region between the circumferential edges 11a, 11b of the first separating membrane 8 and the second separating membrane 9, which opens into an inclined section that finally leads to the second intermediate space 18.

[0045] The sensor unit 14 can be inserted into the sleeve 22, as shown in Fig. 1, or arranged on the sleeve 22. In both cases, the sensor unit 14 is pressure-tightly connected to the sleeve. In the second case, the sensor unit 14 can be arranged in a recess 27 of the sleeve 22.

[0046] The sleeve 22 may also have an opening 25. The second space 18 and the first space 10 can be evacuated via the opening 25. After evacuation, the opening 25 can be closed by means of a sealing device.

[0047] Figure 4 shows an electronic module 100 for the pressure sensor 1 described above.

[0048] The electronics module 100 includes the first pressure sensor 3, the second pressure sensor 16, the evaluation unit 17 with an evaluation input 17a and an evaluation output 17b, the main electronics 28 with a data input 28a and a data output 28b, a control unit 40 with a control module 41 and a switch 42.

[0049] The control module 41 has a control input 41a and a control output 41b.

[0050] The switch 42 is designed either as a controllable switch or as a logic gate. In the case of a switch, it has a first switch position S1 and a second switch position S2 and can be switched between the first switch position S1 and the second switch position S2 by the control module 41 (see Figure 4).

[0051] A first communication line 50 connects the data output 28b, the evaluation input 17a and the control input 41a.

[0052] A second communication line 51 connects the data input 28a, the evaluation output 17b, the control output 41b and, in the case that the switch 42 is a toggle switch, the switch itself, such that in its first switch position S1 the switch connects the data input 28a with the evaluation output 17b and in its second switch position S2 the data input 28a with the control output 41b.

[0053] If the turnout is designed as a logic gate, signals from the control output 41b of the control module 41 are forwarded to the data input 28a of the main electronics 28, depending on the signals from the evaluation output 17b of the evaluation unit 17. The logic gate preferably comprises an OR gate or an exclusive-OR gate, preferably an OR gate with an inverted input. In this case, the control output 41b of the control module 41 is connected to a first input of the turnout, the evaluation output 17b of the evaluation unit 17 is connected to a second input of the turnout, and the data input 28a of the main electronics 28 is connected to an output of the turnout.

[0054] A third communication line 52 connects the control unit 40 to the second pressure sensor 16. Preferably, the third communication line 52 comprises an FC bus.

[0055] The evaluation unit 17 preferably has a first address in a first address range. The control unit 40 preferably has a second address in a second address range. The second address is outside the first address range. The main electronics 28 are capable of sending queries to addresses in the first address range and in the second address range. The evaluation unit 17 is preferably configured such that queries with addresses outside the first address range are ignored by the evaluation unit 17.

[0056] Preferably, the main electronics 28 is suitable for detecting a collision between the first pressure signal Rx and the second pressure signal Rx' by means of a so-called cyclic redundancy check.

[0057] The following describes the procedure for operating the electronic module 100 for the pressure sensor 1. The procedure begins with providing the electronic module 100 as described above. If a switch 42 is used, the switch is in its first position S1. Of course, the switch could also be in its second position S2. In this case, however, a step of switching the switch from the second position S2 to the first position S1 would first be necessary. If a logic gate is used as the switch 42, then providing the module in a specific position is, of course, unnecessary.

[0058] Next, a first pressure signal Rx is transmitted from the first pressure sensor 3 from the evaluation output 17b of the evaluation unit 17 to the data input 28a of the main electronics 28 via the second communication line 51. The first pressure signal Rx represents the first pressure p1 applied to the diaphragm system 7 by the medium 24. Figure 5 shows the first pressure signal Rx as a sequence of data packets (represented as solid lines).

[0059] The first pressure signal Rx exhibits a multitude of pressure values ​​R1, R2, ..., Ri with a first repetition frequency F1, a first signal duration DO, and a data pause P with a data pause duration PO between each pressure value (see Figure 5). The first pressure signal Rx thus represents communication between the first pressure sensor 3 and the main electronics 28, independent of the second pressure sensor 16.

[0060] A pressure query Tx is then sent from the data output 28b of the main electronics 28 to the control input 41a of the control unit 40 via the first communication line 50 (shown in dashed lines in Figure 5). The pressure query Tx is generated by the main electronics 28 at any given time. It should be noted that the pressure query Tx cannot collide with the first pressure signal Rx, since the pressure query Tx is transmitted on the first communication line 50 and the first pressure signal Rx on the second communication line 51. The pressure query Tx preferably has an address that lies in the second address range, i.e., outside the first address range of the evaluation unit 17. This ensures that the evaluation unit 17 receives the pressure query Tx via the first communication line 50 but ignores it. The pressure query Tx is thus sent to the control module 41 and the evaluation unit 17.

[0061] Furthermore, a second pressure signal Rx' is read from the second pressure sensor 16 by the control unit 40 via the third communication line 52 (shown as dashed lines in Figure 5). In this step, the control unit 40 preferably first requests the second pressure signal Rx' from the second pressure sensor 16 and then transmits the second pressure signal Rx' from the second pressure sensor 16 to the control unit 40. This is particularly important if the third communication line 52 is a line used for communication via an FC bus. As is known, in an FC bus, a so-called "slave," here the second pressure sensor 16, only sends data if a "master," here the control unit 40, has explicitly requested data beforehand. Of course, it is also possible for communication via other buses or communication principles to be used over the third communication line 52.In this case, an explicit request would be unnecessary depending on the communication principle. Of course, it is also possible that the reading of the second pressure signal Rx' occurs passively, meaning that the second pressure sensor 16 regularly and automatically provides the second pressure signal Rx' to the control unit 40, or stores it there.

[0062] If the switch 42 is designed as a toggle switch, the switch is subsequently moved to the second switching position S2 for a switching duration SD, so that the switching occurs during the data pause P and the switching duration SD is shorter than the data pause duration DO. Because the second switch position S2 is only occupied during the data pauses P of the first pressure signal Rx, the first pressure signal Rx can be transmitted unhindered, i.e., without collision or time delay, from the evaluation unit 17 to the main electronics 28. In other words, the evaluation unit 17 does not "notice" at all that another sensor is communicating with the main electronics 28 via the second communication line 51. Thus, the existing communication line is used for the additional communication with the second pressure sensor 16 without integrating additional communication lines into the electronics module 100.This leads to cost savings and easy integration of additional sensors. For example, in addition to the second pressure sensor 16, a temperature sensor could also be integrated in the same way.

[0063] Preferably, the switch 42 is only switched from the first switch position S1 to the second switch position S2 if a pressure query Tx has been performed beforehand. Preferably, the second pressure signal Rx' is only transmitted when the switch is in its second switch position S2. Preferably, the second pressure from the second pressure sensor 16 is read via the third communication line 52, independently / asynchronously of the switch position. The pressure values ​​of the second pressure sensor 16 are preferably stored in the control module 41 until they are queried by the main electronics 28.

[0064] If the switch 42 is designed as a logic gate, then of course no prior action, such as flipping a switch, is required.

[0065] Finally, the second pressure signal Rx' is transmitted from the control unit 40 to the data input 28a of the main electronics 28 via the second communication line 51 during a data pause P of the first pressure signal Rx.

[0066] The step of sending a pressure query Tx, as described above, preferably occurs according to a second repetition frequency F2, which is preferably less than 10 Hz. The subsequent second pressure signal Rx' is then, of course, always transmitted within the data pauses P of the first pressure signal Rx.

[0067] Preferably, the main electronics 28 outputs an error message if the first pressure signal Rx collides with the second pressure signal Rx'.

[0068] Preferably, the main electronics 28 outputs a maintenance prediction based on the second pressure signal Rx'. The maintenance prediction transmits, for example, the current pressure value, i.e., vacuum value, from the second pressure sensor 16. Naturally, a warning message can also be issued to the display unit 29 only if a limit value is exceeded, for example, an absolute pressure of 100 mbar. Thanks to the monitoring of the vacuum in the pressure chamber 12 via the second pressure sensor 16, a diaphragm rupture is detected immediately. Such a diaphragm rupture is preferably immediately issued as a warning message to the display unit 29 and / or communicated to a customer interface. For example, the warning message includes a request to shut down the device and to enter a safe state for safety-relevant Z-circuits.

[0069] Reference symbol list

[0070] 1 pressure sensor

[0071] 2 Measuring instrument

[0072] 3 first pressure sensor

[0073] 4 first area

[0074] 5 second area

[0075] 6 process adapters

[0076] 7 Membrane system

[0077] 8 first separating membrane

[0078] 9 second separating membrane

[0079] 10 first space

[0080] 11 a circumferential edge of the first T separating membrane

[0081] 11 b circumferential edge of the second separating membrane

[0082] 12 Pressure chamber

[0083] 13 Pressure transmission path

[0084] 14 Sensor unit

[0085] 15 carriers

[0086] 16 second pressure sensor

[0087] 17 evaluation units

[0088] 17a Evaluation input

[0089] 17b Evaluation output

[0090] 18 second space

[0091] 19 printed circuit board

[0092] 20 connection pins

[0093] 21 pressure transmitters

[0094] 21a Basic body

[0095] 21 b Outer wall of the pressure transmitter

[0096] 22 Sleeve

[0097] 22a Inner wall of the sleeve

[0098] Channel 23

[0099] 24 Medium

[0100] 25 Opening

[0101] 26 Membrane bed

[0102] 28 Main electronics

[0103] 28a Data input

[0104] 28b Data output

[0105] 29 Display unit

[0106] 32 Contact surface 34 Base plate

[0107] 40 Control unit

[0108] 41 Control module

[0109] 41a Tax input

[0110] 41 b Control output

[0111] 42 Switch

[0112] 50 first communication line

[0113] 51 second communication line

[0114] 52 third communication line

[0115] 100 electronic modules

[0116] DO first signal duration

[0117] PO Data pause duration

[0118] F1 first repetition frequency

[0119] F2 second repetition frequency

[0120] P Data pause p1 first print

[0121] Rx first pressure signal

[0122] R1, R2, R3, Ri pressure value

[0123] Rx's second pressure signal

[0124] SD switching time

[0125] 51 first switch position

[0126] 52 second switch position

[0127] Tx print query

Claims

Patent claims 1. Electronic module (100) for a pressure sensor (1) comprising: a first pressure sensor (3), a second pressure sensor (16), an evaluation unit (17) with an evaluation input (17a) and an evaluation output (17b), a main electronics unit (28) with a data input (28a) and a data output (28b), a control unit (40) with a control module (41) and a switch (42), wherein the control module (41) has a control input (41a) and a control output (41b), a first communication line (50) which connects the data output (28b), the evaluation input (17a) and the control input (41a), a second communication line (51) which connects the data input (28a), the evaluation output (17b), the control output (41b) and the switch (42), a third communication line (52) which connects the control unit (40) to the second pressure sensor (16).

2. Electronic module (100) according to claim 1, wherein the switch (42) comprises a logic gate.

3. Electronic module (100) according to claim 1, wherein the switch (42) is a switch and has a first switch position (S1) and a second switch position (S2), wherein the switch can be switched between the first switch position (S1) and the second switch position (S2) by the control module (41).

4. Electronic module (100) according to one of the preceding claims, wherein the third communication line (52) is a l 2 C-Bus is included.

5. Electronic module (100) according to one of the preceding claims, wherein the evaluation unit (17) has a first address in a first address range and the control unit (40) has a second address in a second address range outside the first address range.

6. Method for operating an electronic module (100) for a pressure sensor (1) comprising, Providing an electronic module (100) according to one of the preceding claims, transmitting a first pressure signal (Rx) from the first pressure sensor (3) from the evaluation output (17b) of the evaluation unit (17) to the data input (28a) of the main electronics (28) via the second communication line (51), wherein the first pressure signal (Rx) has a plurality of pressure values ​​(R1 , R2, Ri) with a first repetition frequency (F1) and a first signal duration (DO) and between each pressure value (R1 , R2, Ri) a data pause (P) with a data pause duration (PO), sending a pressure query (Tx) from the data output (28b) of the main electronics (28) to the control input (41 a) of the control unit (40) via the first communication line (50), reading a second pressure signal (Rx') from the second pressure sensor (16) by the control unit (40) via the third communication line (52), Transmission of the second pressure signal (Rx') from the control unit (40) to the data input (28a) of the main electronics (28) via the second communication line (51) during a data pause (P) of the first pressure signal (Rx).

7. Method according to claim 6, wherein the switch (42) is a switch and the switch is in its first position (S1) when transmitting the first pressure signal (Rx), and the switch is in its second position (S2) when transmitting the second pressure signal (Rx').

8. Method according to claim 6 or 7, wherein the readout step comprises requesting the second pressure signal (Rx') from the control unit (40) to the second pressure sensor (16) and transmitting the second pressure signal (Rx') from the second pressure sensor (16) to the control unit (40).

9. Method according to any one of claims 6 to 8, wherein the step of sending a pressure query (Tx) is performed according to a second repetition frequency (F2), preferably less than 10 Hz.

10. Method according to any one of claims 6 to 9, wherein the main electronics (28) outputs an error message when the first pressure signal (Rx) collides with the second pressure signal (Rx').

11. Method according to any one of claims 6 to 10, wherein the main electronics (28) outputs a maintenance prediction based on the second pressure signal (Rx').

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