Field device and functional unit for a field device

Abstract

The invention relates to a field device (1) comprising a plurality of functional units (M1, M2, M3, M4) and an energy supplier (6) for the field device (1). The sum of the individual energy consumptions of all functional units (M1, M2, M3, M4) is greater than the maximum of the energy that can be delivered from the energy supplier (6) to the field device (1). At least two of the functional units are assigned or can be assigned a priority, a functional unit (M2) having a higher priority influences the energy consumption of a functional unit (M3) having a comparatively lower priority, such that the overall energy consumption of all functional units (M1, M2, M3, M4) from the energy supplier (6) is not greater than the maximum of the energy that can be delivered from the energy supplier to the field device (1). In order to influence the energy consumption of a functional unit (M3) having a lower priority, the line (5) that supplies the functional unit having a lower priority is routed through a functional unit (M2) having a higher priority. As a result, it is possible to flexibly equip, upgrade or replace functional units and to keep the outlay for matching energy management of the functional units comparatively low.

Description

Technical Field

[0001] The present invention relates to a field device comprising multiple functional units and a functional unit for such a field device. Background Technology

[0002] In industrial process automation, distributed field devices are frequently used—that is, devices located near the process to be monitored or controlled and outside the control room used to control the process. These devices are called field devices. They provide, for example, measurements of the process (e.g., temperature, pressure, flow rate) and / or influence the process (e.g., valve position adjustment). Field devices that provide information about the process are often also called sensors or measurement transducers. Field devices that influence the process are often called actuators or actuators.

[0003] Field equipment is often not housed in protected cabinets but is directly exposed to harsh environmental conditions and meets the safety requirements of matching processes. This results in high demands on the quality, robustness, and availability of field equipment. It must be able to operate frequently in high-temperature ranges and meet its own safety, fire-resistant, and explosion-proof standards.

[0004] "Smart" or intelligent field devices with a wide range of communication, diagnostic, configuration and parameterization options, as well as functions for data processing, are increasingly being used.

[0005] Field devices typically connect to the lowest layer of industrial communication networks, such as fieldbuses, and are able to send process information to higher-level facilities, such as control and / or regulation facilities or facilities for process monitoring and diagnostics, or receive information on control parameters. Intelligent field devices can also provide information about themselves (operating status, configuration, software version, firmware version) to higher-level process management systems. Examples of communication mechanisms used in this application are HART, PROFIBUS, CAN, or Ethernet-based: PROFINET, Ethernet IP, MODUBUS TCP, TSN, or a single-pair Ethernet connection.

[0006] In a broader context, field devices typically include all other devices located near the process and connected to communication systems, such as fieldbuses. An example of this is remote I / O, which connects analog or digital sensors or actuators to communication systems, gateways, or link devices.

[0007] A particular challenge for many field devices is that, especially due to safety requirements such as fire and explosion protection, the electrical energy delivered to them is limited.

[0008] In this context, to save on cabling, power and communication are often supplied via a common wiring system. For example, so-called two-conductor technology (or two-wire technology) is used, in which communication signals are transmitted and power circuits for field devices are supplied via a common line. Here, the first line is used for the outbound journey and the second line is used for the return journey. An example of this is a two-conductor loop according to the 4mA to 20mA standard. Communication based on four-conductor technology can also be used.

[0009] Power over Ethernet (PoE) and Single-Pair Ethernet (SPE) are also increasingly used, in which network-capable devices are also powered via Ethernet cables. Later, Ethernet Advanced Physical Layer (APL) was applied, where communication and functionality are achieved through a single 2-core cable, and it is particularly suitable for the specific requirements of the process industry.

[0010] As a replacement for externally powered field devices, self-sufficient field devices are also known, which are powered, for example, by integrated batteries. However, the energy supplied is more limited here.

[0011] Modularity of structure is important for fieldbus itself. For example, modular field devices consisting of a main electronic system and multiple modular components (or modules) are known from DE 10 2008 030315A1.

[0012] DE 10 2006 011 501 A1 discloses a field device with internal modularity, wherein a first group of components includes all components essential to the core function, and a second group of components includes all components optional for extended functions. The components in the first group are continuously powered. The components in the second group are combined into functionally related, individually powered extended function modules, which can be activated as needed by switching power supply.

[0013] Here, activation can be performed either event-controlled or periodically. In event-controlled activation, a time period can be defined, after which the voltage of the second group of components is cut off as a final step. However, other details regarding when and how the activation / deactivation or switching of the second component, and the energy consumption of the second group of components, occurs are not disclosed.

[0014] EP 3 182 073 A1 discloses a level liquid measuring device having at least two functional units connected in series for external power supply. A decoupling circuit exists between the two functional units to distribute the energy supplied between them as needed. Here, the power supply line with relatively low priority is guided by the decoupling circuit. The control of the decoupling circuit and the influence of the energy consumption of the lower-priority functional units are achieved by a central upper-level controller of the level liquid measuring device.

[0015] Energy management for field devices in process automation, having a first module and at least one second module, is known from DE 10 2015 115 275 A1, wherein the field devices are powered via a two-conductor bus. The first module consumes at least temporarily more energy than the two-conductor bus continuously supplies. Here, the second module is continuously powered via the two-conductor bus, and the operation of the first and second modules is controlled such that the second module takes precedence over the first module, and the first module is inactive at least temporarily where possible. The second module informs the first module of its operation, and the first module matches its operation such that the total energy required by the field devices is supplied via the two-conductor bus. Therefore, there is intelligence in the first module regarding whether the first module must be used as a whole and, where possible, how its operation is matched.

[0016] However, this solution is difficult to implement on field devices that can be flexibly configured with different functional units. In particular, it is suitable for field devices where functional modules can be flexibly assembled, upgraded to other states (e.g., activated via software), or replaced by other devices. This is because assembling, upgrading, or replacing functional units is often constrained by the compatibility of functional units already present or remaining in the field device to achieve the necessary energy management for the field device. Summary of the Invention

[0017] Therefore, the purpose of this invention is to provide a field device in which functional modules can be flexibly assembled, upgraded or replaced, wherein the consumption for matching energy management can be kept low.

[0018] The field device according to the invention includes multiple functional units and a power supply for the field device, wherein the sum of the individual energy consumption of all functional units is greater than the maximum energy that can be delivered from the power supply to the field device. At least two, preferably all, of the functional units are assigned or can be assigned priorities, wherein a functional unit with higher priority (hereinafter referred to as a "high-priority functional unit") influences the energy consumption of a functional unit with relatively lower priority (hereinafter referred to as a "low-priority functional unit") such that the total energy consumption of all functional units from the power supply does not exceed the maximum energy that can be delivered from the power supply to the field device. To influence the energy consumption of the lower-priority functional units, the power supply lines for the lower-priority functional units are routed through the higher-priority functional units.

[0019] Because the power supply lines for low-priority functional units are routed through high-priority functional units, high-priority functional units directly access the power supply of lower-priority functional units and can independently influence them according to their own needs. When assembling, upgrading, or replacing such functional units, integrated circuitry and logic for influencing the power supply of low-priority functional units can be provided in conjunction with the high-priority functional units. Therefore, no or minimal changes to other field devices are required.

[0020] The power supply for field devices can include external energy, such as energy via a power supply interface, or internal energy, such as energy from internal energy storage (e.g., batteries).

[0021] In the case of external power transmission, delivery can be achieved, for example, by a two-conductor bus, which can be coupled to the power supply interface of the field device. The two-conductor bus is preferably used for the joint transmission of signal and energy. However, external power transmission can also be achieved by a multi-conductor bus, which can be coupled to the power supply interface of the field device. The multi-conductor bus is preferably used for the current-separated transmission of signal and energy.

[0022] A very simple effect on the energy consumption of low-priority functional units can be achieved by having higher-priority functional units include switches arranged in the circuit. These switches can then be turned on or off by themselves according to the energy needs of the higher-priority functional units, thus disconnecting or reconnecting the energy supply to the lower-priority functional units.

[0023] Alternatively, the functional unit may include a controllable current-limiting element, such as a controllable resistor, arranged in the circuit to affect the power consumption of lower priority functional units.

[0024] According to the structurally simple design scheme, the higher priority functional unit has a first interface and a second interface, through which the functional unit is connected to the line, wherein the switch or controllable current limiting element is connected to the conductor of the line that is guided from the first interface to the second interface.

[0025] Advantageously, switches or controllable current-limiting elements can be directly controlled by functional units with higher priority. This enables simple assemblability, upgrades, or replacement of functional units in field equipment.

[0026] According to a particularly simple design of the invention, priority is permanently assigned to at least two functional elements. This fixed assignment can be achieved, for example, by the order in which the functional units are arranged along the power supply lines within the field device. This order can be implicitly given, for example, by the mounting positions of the functional units within the field device.

[0027] In functional units with varying energy consumption, it is advantageous to configure field devices for reconfiguration or upgrades when prioritizing them. This prioritization can be achieved (e.g., through coordination by a central functional unit) during initial commissioning, at each configuration change, or as required by one of the functional units. Subsequently, changes or reassignments of priorities can be made, for example, by manually or automatically setting the order of the functional units' power supply lines within the field devices. This setting can be achieved, for example, by matching the power supply lines of the functional units (i.e., the connection from the line interface to the functional unit with the power supply line).

[0028] According to another, very simple circuit design, the circuit used to power the low-priority functional unit also powers the high-priority functional unit. Subsequently, the two functional units are advantageously connected to the circuit sequentially with decreasing priority.

[0029] For communication connections in field devices that are simple and have low complexity, communication connections to functional units with lower priority are also guided through functional units with higher priority.

[0030] Subsequently, the communication connection can also be used to communicate with functional units that have higher priority.

[0031] According to a particularly simple design, two functional units are then sequentially connected to the communication connection with decreasing priorities. This allows the higher-priority functional unit to influence the communication (e.g., interrupts) of the lower-priority functional unit.

[0032] Here, higher-priority functional units may also include repeaters for communication connections.

[0033] According to a particularly advantageous design, at least one of the at least two functional units is implemented as a functional module capable of being assembled to a field device. Preferably, the module can be removably secured to the field device.

[0034] In particular, power consumers are important for functional units or modules. Therefore, communication modules (especially radio modules), sensor modules, transmitting modules, displays, measurement data processing modules, control modules, or regulation modules are preferably involved. Furthermore, service interface modules may also be involved, through which maintenance personnel can connect to field devices using mobile devices (e.g., laptops, tablets, smartphones) for parameterizing, configuring, and diagnosing the field devices.

[0035] The functional unit for a field device having multiple functional units according to the present invention includes:

[0036] - The first electrical interface used to connect the line to the power supply of field equipment.

[0037] - An electrical second interface for the power supply used to connect lines to other functional units of field equipment.

[0038] - A line segment is guided from the first interface through the functional unit to the second interface. The line segment is implemented to enable other functional units to connect to the power supply of field devices.

[0039] Preferably, the functional unit is implemented as an assemblable functional module that can be detachably fastened to the field equipment.

[0040] According to a particularly advantageous design, a switch or a controllable current-limiting element is connected to the line segment. This allows for a very simple influence on the energy consumption of low-priority functional units.

[0041] Preferably, the switch or controllable current-limiting element is controlled by the functional unit. This enables simple assemblability, upgradeability, or replacement of functional units in field devices. Attached Figure Description

[0042] The invention and its other advantageous designs will now be described in detail with reference to the embodiments shown in the accompanying drawings; the drawings show:

[0043] Figure 1 A first embodiment of the field device according to the present invention is shown.

[0044] Figure 2 Show Figure 1 A more detailed view of the functional units,

[0045] Figure 3 A second embodiment of the field device according to the present invention is shown.

[0046] Figure 4 A third embodiment of the field device according to the present invention is shown.

[0047] Figure 5 A fourth embodiment of the field device according to the present invention is shown.

[0048] For simplicity, single-guide views are selected in the attached diagrams. In reality, however, at least two guides (positive guide and negative guide) are present in each view. Detailed Implementation

[0049] Figure 1 The simplified schematic diagram of the field device 1 includes multiple functional units M1, M2, M3, and M4, which are supplied with electrical energy from the power supply 6 of the field device 1. The power supply 6 can simultaneously extract its energy directly or indirectly from the outside via the power supply interface 2, for example via a two-conductor loop, which is preferably used for the joint transmission of signal and energy, or via a multi-conductor loop, which is used for the separate transmission of signal and energy. Due to safety requirements, particularly fire and explosion protection, the transmission of external energy via the interface 2 is limited. Alternatively, the power supply 6 can also obtain its energy from the battery 3 of the field device 1. Energy extraction or transmission is also limited here to ensure the longest possible battery life.

[0050] Functional unit M1 can be, for example, a central functional unit that powers the entire field device 1 and is responsible for communication between the central controller of field device 1 and functional units M2, M3, and M4.

[0051] Functional units M2, M3, and M4 can be, for example, sensor modules, transmitting modules, communication modules (especially radio modules), displays, measurement data processing modules, control modules, or adjustment modules.

[0052] Sensor modules can be used to detect physical parameters such as temperature, pressure, flow rate, vibration, and liquid level.

[0053] The transmitting module (often referred to as a "measurement converter") enables analog-to-digital conversion of measured values, preparation and / or preprocessing of digitized measured values ​​where possible, and further processing for subsequent communication of the digitized measured values ​​to a remote receiver.

[0054] Communication between digitized measurements and a long-distance receiver can be achieved via a communication module, either wired or wirelessly. The radio module can operate according to standards such as HART, Bluetooth Low Energy, 3G, 4G, or 5G.

[0055] The display can be used to parameterize, configure, and diagnose field devices.

[0056] Service interfaces enable maintenance personnel to connect to field devices via mobile devices (such as laptops, tablets, and smartphones) for parameterizing, configuring, and diagnosing field devices.

[0057] The measurement data processing module can be used for on-site analysis of measurement data. For example, it can perform statistical evaluation, KPI determination, and classification of measurement data according to standards EN 10816-6, -7, and -3. With the help of machine learning, it can identify anomalies in the measurement data and generate predictions of future process curves for the measurement data.

[0058] The control module is used to send rated values ​​for control parameters (e.g., valve positions) used to adjust the process. The regulating module, correspondingly, is used to send rated values ​​for adjusting process parameters.

[0059] Therefore, through field device 1, an intelligent field device powered externally, such as a pressure measuring device, flow measuring device, level measuring device, or a self-sufficient multi-channel sensor, can be used to detect engine vibration and temperature.

[0060] The functional unit can be housed within the enclosure of the field device 1. However, it can also be located outside such an enclosure. For example, a radio module for extending the transmission range may be located outside the enclosure. The functional unit or module may also have its own separate enclosure.

[0061] When the sum of the individual energy consumption of all functional units M1, M2, M3, and M4 exceeds the maximum energy that can be supplied from power supply 6, energy management is required. This ensures that the field devices or functional units are operated such that the total energy consumption of all functional units M1, M2, M3, and M4 does not exceed this maximum value. Otherwise, there is a risk that insufficient energy will be provided to operate the central functional unit, which endangers its intended operation and could lead to an unsafe state or even failure of the functional unit or the entire field device.

[0062] Therefore, functional units M2, M3, and M4 are assigned or can be assigned priorities P1, P2, or P3. For example, P1 relates to the highest priority, P2 to the medium priority, and P3 to the lowest priority. Here, functional unit M2 affects functional units with relatively lower priorities (e.g., functional unit M3), thereby maintaining the maximum value for overall energy consumption.

[0063] In order to influence the energy consumption of the medium-priority functional unit M3, line 5, which supplies power to the medium-priority functional unit M3, is redirected through the high-priority functional unit M2. Similarly, line 5, which supplies power to the low-priority functional unit M4, is redirected through the medium-priority functional unit M3.

[0064] Therefore, each high-priority functional unit accesses the power supply of a relatively lower-priority functional unit and can independently influence it. When assembling, upgrading, or replacing such a high-priority functional unit, for example, functional unit M2, all the circuitry and logic for influencing the power supply of the lower-priority functional units, for example, M3 (and M4), can be provided integratedly with high-priority functional unit M2. Therefore, it is not necessary to change the remaining field devices 1 or other functional units M1, M3, and M4.

[0065] In order to influence the energy consumption of the medium-priority functional unit M3, the high-priority functional unit M2 has a switch 12 arranged in line 5. This switch 12 can then be opened or closed by itself according to the energy demand of the high-priority functional unit M2, and thus disconnect or reconnect the power supply 6 of the low-priority functional unit M3.

[0066] On the other hand, in order to influence the relatively lower priority functional unit M4, functional unit M3 includes a controllable current limiting element 13, such as a controllable resistor, arranged in line 9.

[0067] Here, line 5, which supplies power to each low-priority functional unit, also supplies power to each high-priority functional unit. For this purpose, functional units M2, M3, and M4 are connected to line 5 in descending order of priority.

[0068] According to a particularly simple design of the invention, priority is permanently assigned to functional units M2, M3, and M4. This fixed assignment can be achieved, for example, solely through the order in which the functional units are arranged along the power supply lines 5 within the field device 1. This order can be implicitly given, for example, through the installation positions of the functional units M2, M3, and M4 within the field device 1.

[0069] In functional units with varying energy consumption, it is advantageous to configure or upgrade field devices (e.g., via software) by setting field device 1 to renegotiate or even negotiate priorities between functional units. This negotiation can be (e.g., coordinated by central functional unit M1) during initial commissioning, at each configuration change, or as required by one of functional units M2, M3, and M4. Subsequently, changes or reassignments of priorities can be achieved, for example, by manually or automatically setting the order of the functional units along power line 5. This setting can be achieved, for example, by changing (or swapping) the installation positions of functional units M2, M3, and M4 in field device 1, or (while maintaining the same safe position) by matching the power connections of functional units M2, M3, and M4 to power line 5 (i.e., the connection from the line interface to functional units M2, M3, and M4 with power line 5).

[0070] Communication connection 8 (e.g., a communication bus) is used for communication between central functional unit M1 and functional units M2, M3, and M4, and is connected to the communication component 7 (e.g., the host of the communication bus) of central functional unit M1. Here, communication connection 8 to a lower-priority functional unit (e.g., M3) is routed through a relatively higher-priority functional unit (e.g., M2). Similar to the power supply situation, functional units M2, M3, and M4 are also connected to communication connection 8 in descending order of priority. Thus, higher-priority functional units also affect the communication of lower-priority functional units.

[0071] according to Figure 2 The functional units according to the invention should be described more precisely with reference to illustrative embodiments, herein as... Figure 1 The structure of functional unit M2.

[0072] Functional unit M2 has a power supply for connecting to field device 1, for example, according to Figure 1 The power supply unit 6 has an electrical first interface S1 on line 5. Furthermore, functional unit M2 has an electrical second interface S2 for connecting power supply lines for other functional units of field device 1, specifically line 5 to functional unit M3. Line segment 5' leading from the first interface S1 to the second interface S2 is configured such that functional unit M3 is connected to power supply unit 6 via line 5. Here, switch 12 is connected in line segment 5'.

[0073] Furthermore, functional unit M2 has a means for connecting to a communication line, as described herein. Figure 1 The central functional unit M1 has a first communication interface K1 on the communication line 8 of the communication component. Furthermore, functional unit M2 has a second communication interface K2 for connecting to other functional units for field devices, specifically line 8 to functional unit M3. Line 8' leading from the first communication interface to the second communication interface K2 is configured such that functional unit M3 is connected to the communication component 7 via line 8.

[0074] Furthermore, functional unit M2 includes its own power supply 10 and controller 11 (e.g., microcontroller 11). Power supply 10 is connected to line segment 5' between interface S1 and switch 12 and is powered by line 5. Controller 11 is connected to communication line 8' between interfaces K1 and K2 (which can also be guided through controller 11 depending on the type of communication connection). Controller 11 is configured to generate signals for turning switch 12 on or off.

[0075] Preferably, the functional unit M2 is implemented as a functional module, which can be removably fastened by means of the fastening device 14 according to... Figure 1 On the field equipment 1.

[0076] Figure 3 It shows Figure 1 Field device 1, however, functional unit M3 is not installed in field device 1. Therefore, the installation position for functional unit M3 in field device 1 is not installed. Here, power supply line 5 is bridged between functional units M2 and M4 by means of line segment 5". Correspondingly, communication line 8 is bridged between functional units M2 and M4 by means of line segment 8".

[0077] Figure 4 Another embodiment of the field device of the present invention is shown. (Compared to...) Figures 1 to 3 In contrast, each corresponding component is labeled with the same number. Figure 4 The field device 20 shown has three functional units M1, M2, and M3. Functional unit M1 is implemented as a central transmitting module, which is coupled to sensors (not shown in detail) for detecting parameters such as pressure, temperature, and level. Functional unit M2 is implemented as a radio module, and functional unit M3 is implemented as a display. The radio module M2 is assigned a higher priority than the display M3.

[0078] When display M3 is present, radio module M2 can turn off display M3 by means of switch 12 and use the additional energy required by display M3 for display purposes. This is, for example, when radio module M2 temporarily requires more energy for transmission operation. Transmitting module M1 is completely unaware that display M3 is not displaying anything when radio module M2 operates as it does.

[0079] and Figure 1 and Figure 2 Unlike other communication modules, communication line 8 is divided into two lines, 8a and 8b. Line 8a is used to transmit data from transmitting module M1 to radio module M2 and display M3. Conversely, line 8b is used to transmit data from radio module M2 and display M3 back to transmitting module M1. Here, MT is used to indicate the output, RX to indicate the input, and V to indicate the input or output of power line 5. Correspondingly, radio module M2 also has two first communication interfaces K1', K1" and two second communication interfaces K2', K2".

[0080] Switch 25 can be used to shut down the communication between the radio module M2 and the display M3.

[0081] Data is also transmitted from the transmitting module M1 to the display M3 via line 8a'. Additionally, the radio module M2 transmits data to the transmitter via line 8b' and receives corresponding responses. However, data from the transmitting module M1 to the radio module M2 is not forwarded to the display due to switch 25. Communication between the radio module M2 and the transmitting module M1 is possible even when the display is not on the field device 20.

[0082] Here, the communication connections from the transmitting module M1 to the radio module M2 and to the display M3 can be achieved as follows: Figure 4 The parallel connection shown is achieved via two line paths 26 and 27, allowing the radio module M and display M3 to be connected in parallel and separated only for transmission to the transmitting module M1 via switch 25. As a result, display M3 also receives responses to inquiries about radio module M2.

[0083] exist Figure 5 As shown Figure 4 In the replacement design, the radio module M2 in field device 30 includes an intelligent repeater 40, which is connected to lines 5, 8a, and 8b. This repeater 40 receives messages from the transmitting module M1 only when it is facing the display M3 or the transmitting module M1, or it does not forward messages when it is used with the radio module M2. According to... Figure 4 Parallel connections are made at bus-type interfaces (e.g., I / O). 2 C) is useful, and according to Figure 5 The store-and-forward method is advantageous for point-to-point connections (such as UARTs).

Claims

1. A field device (1) comprising a power supply (6) for the field device (1) and a plurality of functional units, wherein, The sum of the individual energy consumption of all functional units is greater than the maximum energy that can be delivered from the power supply (6) to the field device (1), wherein at least two of the functional units are assigned or can be assigned priorities (P1, P2), wherein the functional unit with higher priority affects the energy consumption of the functional unit with relatively lower priority, such that the total energy consumption of all functional units from the power supply is not greater than the maximum energy that can be delivered from the power supply (6) to the field device (1), wherein, in order to affect the energy consumption of the functional unit with lower priority, the line (5) supplying energy to the functional unit with lower priority is guided through the functional unit with higher priority, wherein the functional unit with higher priority includes a switch (12) arranged in the line (5) or a controllable current limiting element (13) arranged in the line (5), characterized in that the switch (12) or the controllable current limiting element (13) can be controlled by the functional unit with higher priority, wherein all the circuitry and logic for affecting the energy supply of the functional unit with relatively lower priority can be provided integratedly with the functional unit with higher priority. Among them, functional units with higher priority - Implemented as a functional module that can be assembled to the field device (1) and can be detachably connected to the field device (1), - It has its own shell, and - Implemented as a transmitting module, display, communication module, sensor module, service interface, measurement data processing module, control module, or adjustment module.

2. The field device (1) according to claim 1, wherein, The higher priority functional unit has a first interface (S1) and a second interface (S2). The higher priority functional unit is connected to the line (5) via the first interface and the second interface. The switch (12) or the controllable current limiting element (13) is connected to the line segment (5') of the line (5) that leads from the first interface (S1) to the second interface (S2).

3. The field device (1) according to claim 1 or 2, wherein, The priority is persistently assigned to at least two functional units.

4. The field device (1) according to claim 1 or 2, wherein, The field device (1) is implemented such that the priority between at least two functional units is negotiable.

5. The field device (1) according to claim 1 or 2, wherein, The line (5) is also used to power functional units with higher priority.

6. The field device (1) according to claim 5, wherein, The two functional units are connected to the line (5) in sequence with decreasing priority.

7. The field device (1) according to claim 1, wherein, Communication connections with lower-priority functional units are also routed through higher-priority functional units.

8. The field device (1) according to claim 7, wherein, The communication connection is also used to communicate with functional units that have higher priority.

9. The field device (1) according to claim 8, wherein, The two functional units are connected to the communication connection in descending order of priority.

10. The field device (1) according to any one of claims 7 to 9, wherein, The higher-priority functional units include repeaters (40) for the communication connection.

11. The field device (1) according to claim 1, wherein, The communication module is implemented as a radio module.

12. A functional unit for a field device (1), the field device having multiple functional units, wherein, The functional unit includes: - An electrical first interface (S1) for connecting the line to the power supply (6) of the field device. - An electrical second interface (S2) for connecting lines to other functional units of the field equipment. - A line segment (5') guided from the first interface (S1) through the functional unit to the second interface (S2), the line segment being configured to connect the other functional unit to the power supply (6) of the field device (1). Among them, a switch (12) or a controllable current limiting element (13) is connected to the line segment (5'). The characteristic is that the switch (12) or the controllable current limiting element (13) can be controlled by the functional unit. Among them, the functional unit -Integrates all the circuitry and logic that affect the power supply to the other functional units. - Implemented as a functional module that can be assembled to the field device (1) and can be detachably connected to the field device (1), - It has its own shell, and - Implemented as a transmitting module, display, communication module, sensor module, service interface, measurement data processing module, control module, or adjustment module.

13. The functional unit according to claim 12, wherein, The communication module is implemented as a radio module.

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