Field device system, method for adjusting a process fluid flow of a process plant and process plant

Abstract

Field device system for adjusting a process fluid flow of a process plant (1), such as a chemical plant, a power plant, a food processing plant or the like, comprising: - several field devices (9), such as a control valve and / or a pump, which can be controlled by a process controller (3); and - a data center (7) for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices (9); wherein the data center (7) is designed to pre-evaluate and / or pre-filter the received data and to transmit the pre-evaluated and / or pre-filtered data to the process controller (3); wherein the data center (7) is further designed to perform a diagnosis, a trend analysis, an operating state analysis and / or a predictive analysis based on the pre-evaluated and / or pre-filtered data.

Description

The invention relates to a control valve for adjusting a process fluid flow in a process engineering plant, such as a chemical plant, for example a refinery, a power plant, for example a nuclear power plant, a food processing plant, or the like, an attachment for a control valve, a field device system and a method for reducing downtime of a control valve. Various technologies are used for data transmission in process plants. Many control valves use a combined two-wire connection for combined signal and power transmission. A 4–20 mA signal is transmitted from a central control unit, such as a central control room of a process plant, to the control valve via this two-wire connection. For example, a 4 mA control signal can cause the control valve to move to a closed position, whereas a 20 mA signal can cause the control valve to move to a fully open position. Signals in the range between 4 and 20 mA can cause the control valve to assume a predetermined intermediate position between the closed position and the fully open position, which can, for example, be proportional to the current signal. A passive field device in the form of a sensor can transmit an analog 4 mA signal.A 20 mA signal is transmitted to a central control unit to report information about a process plant, such as a part or component of the plant or a process fluid. For example, a current signal proportional to a specific pressure range can be transmitted from a pressure sensor to a central control unit. The transmission of information or data using a 4–20 mA signal is limited to very small data volumes. Commonly used for data transmission in process plants are the HART protocol, the FOUNDATION Fieldbus protocol, the PROFIBUS protocol, and a number of other digital communication technologies. Since 2007, HART has been part of the fieldbus standard IEC 61158. For data transmission according to the HART protocol, a high-frequency oscillation, for example ± 0.5 mA, is superimposed on an analog signal, such as a 4–20 mA signal. This allows for the representation of a digital 1 at a frequency of 1.2 kHz and a digital 0 at a frequency of 2.2 kHz. HART enables the transmission of process and diagnostic information as well as control signals between control valves and a higher-level control unit, such as a central control room. In some process plants, data is transmitted from a central control unit to control valves using Power over Ethernet (PoE) technology. PoE is a technology that powers network-enabled devices via an 8-wire Ethernet cable. Data transmission via PoE conforms to the IEEE 802.3af standard (July 2003). Power over Ethernet systems are designed to eliminate the need for power cables, enabling network-enabled devices to be powered in hard-to-reach or confined spaces. According to the IEEE 802.3af standard, participating devices can be categorized as power sourcing equipment (PSE) and power devices (PD). The operating voltage for the power devices is 48 V. The maximum current draw of the devices is 350 mA, with up to 400 mA permitted, resulting in a maximum power consumption of 14.5 W per device.For power transmission, spare wires and / or signal-carrying wires of the Ethernet cable can be used. PoE enables the rapid transmission of large amounts of data. The power density of PoE technology precludes its use in potentially explosive atmospheres. The use of PoE technology requires a significantly higher investment than analog 4-20 mA communication. Retrofitting existing process plants with PoE technology also requires substantial investments, which are often uneconomical. A control valve powered via an Ethernet connection (Power over Ethernet) and an associated commissioning procedure are described in DE 10 2006 036 770 A1. The so-called Advanced Physical Layer (APL) technology, specifically according to the IEEE P802.3cg (2016) standard, implements an approach to linking data transmission via Ethernet on the one hand and established and widely used communication technologies in process plants on the other. Unlike PoE technology, APL technology is designed to be particularly suitable for integrating network-enabled devices in potentially explosive atmospheres (Zone 0 and 1 / Division 1). Zone 0 describes an area where an explosive gas-air mixture is present permanently or for extended periods. Zone 1 describes an area where combustible or conductive dust particles are present, as well as areas where an explosive gas-air mixture may be present briefly under normal operating conditions. APL technology should also make it possible to design field devices to be intrinsically safe.Using twisted-pair wiring (twisted-care wiring according to 10BASE-T1L), data transmission rates of 10 Mb / s up to 100 Mb / s and more are achievable. Process plants with APL technology can be equipped with a trunk data and power transmission line, typically up to 1000 m long, extending from a central control unit to an APL field switch. These trunk lines are designed to transmit power up to 54 W. Multiple field devices can be connected to the APL field switch via spur data and power transmission lines, typically up to 200 m long. The spur lines are designed to provide a maximum power output of 500 mW.A standard IEC 61158 Type A fieldbus cable is typically used for data and power transmission. This cable features twisted pairs and an electrically shielded jacket (also known as a shield). According to the APL standard IEEE P802.3cg (2016), electrically shielded cables must be used for the connection between the APL field switch and each individual field device. Up to five field devices can be connected to a single spur line. Multiple APL field switches, for example, a maximum of five to a maximum of ten, can be connected to a single trunk line. APL technology is compatible with the operation of field devices in potentially explosive atmospheres. For this purpose, a low power density may be implemented to prevent the electrical and / or thermal energy present in a field device from exceeding an ignition threshold, even under abnormal operating conditions.The APL field switches and field devices are designed to be ignition-proof (explosion-proof) according to protection class “Ex d”. APL technology allows the transmission of large data volumes and is characterized by its compatibility with existing two-wire communication systems. However, many users complain about the relatively high investment costs for upgrading or retrofitting an entire system, even with APL technology. To reduce the costs and installation space required for APL technology, WO 2022 / 043103 A1 proposes positioning an APL field switch together with an attached positioner in a common explosion-proof housing. This housing is designed separately and at a distance from a control valve, whose actuator is controlled via the positioner. However, the solution from WO 2022 / 043103 A1 does not fully exploit the potential of APL technology. APL technology allows for the installation of high-speed data transmission lines and power supplies over distances of up to 200 meters in Zone 0 hazardous areas via two-wire branch lines. This enables the control valves themselves to be equipped with computing units, such as the positioner and / or a sensor. As a result, the control valves can be configured as network-enabled devices, increasing their functionality and flexibility and simplifying the cabling effort for control valves with numerous functionalities. It is expected that the use of network-enabled control valves, especially in conjunction with APL technology, will lead to the introduction of new functionalities and security measures at increasingly shorter intervals, particularly against unauthorized network access to the control valves. This will result in an increased frequency of updates on the one hand and a higher risk of failure due to the increased complexity on the other. Currently, both the failure and the update of field devices result in downtime of the control valve and, in the worst case, of the entire process plant, leading to high costs. US patent 2021 / 0181701 A1 discloses a process control network for field devices that incorporate sensors and actuators. The individual field devices are connected to the process control system, which is stored in a cloud, via a network module, potentially utilizing APL technology. Safety and network diagnostics can be performed using the network module. US patent 2021 / 0181701 A1 does not yet recognize or fully exploit the potential of novel communication technologies for process engineering. German patent DE 102 09 734 A1 discloses a method for reducing the amount of process data to be transmitted by a field device. The process data generated in the interval between two data transmissions is evaluated and stored, with the evaluation reducing the amount of process data. The reduced process data is then transmitted to a process control center. During the evaluation, the process data is categorized as static and dynamic data, with only changed data being classified and transmitted as dynamic data, while unchanged static data is transmitted only as a binary state value. Transmission occurs only when predefined conditions such as time intervals, times of day, or alarm events are met, further reducing the number of data transmissions. It is therefore an object of the invention to overcome the disadvantages of the prior art, in particular to make a field device system and a method for adjusting a process fluid flow of a process engineering plant more effective and / or functional. The problem is solved by the subject matter of the independent claims. According to a first aspect of the present invention, a field device system is provided for adjusting a process fluid flow of a process engineering plant, such as a chemical plant, a power plant, a food processing plant or the like. The field device system comprises several field devices. For example, a field device is a control device, a measuring device, or an actuator. A field device can, for example, be a control valve for adjusting a branch of the process fluid flow. For example, a field device is a control valve or a pump. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. For example, the control valve can be actuated pneumatically, electrically, or hydraulically. The field device can be operated with auxiliary energy, such as pneumatic auxiliary energy, wherein, in particular, a preferably pneumatic actuator can be actuated via a positioner, especially an electropneumatic one.The field device system, and in particular the field device itself, can be either a freestanding or integrated field device capable of handling the fluids encountered during processing in large-scale plants under explosion protection. Generally, field devices are designed to influence, and in particular control and / or regulate, the process fluid flow within the process plant. The field device system further comprises a data center for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices. The sensor data can be acquired by means of at least one sensor separate from the field device, for example, an optical and / or acoustic sensor. The sensor can be, for example, a camera and / or a microphone. The sensor is configured to acquire image and / or sound data. For example, the image and / or sound data may be image and / or sound data attributable to at least one field device. The sensor may also be, for example, an optical microphone according to EP 3 351 838 A1, the content of which is specified herein for the sake of completeness. The data center can be connected to at least one sensor via a communication network, for example, using Ethernet-APL. The data center can also be connected to field devices via the communication network, also using Ethernet-APL. Furthermore, the data center can be connected to a higher-level process control system via Ethernet-APL or other communication links, such as a bus connection, for example, via HART, PROFIBUS, FOUNDATION Fieldbus, or similar. According to the first aspect of the invention, the data center is designed to pre-evaluate and / or pre-filter the received data and transmit the pre-evaluated and / or pre-filtered data to the process control system. Particularly in modern process plants with numerous sensors, field devices, and recorded measurement data, the amount of data is very high, which is why prior art field device systems tend to overload the signal transmission equipment. Pre-filtering and pre-evaluation reduce the amount of data to be transmitted, thus reducing the risk of overload. Furthermore, the reduced data volume can then be transmitted over a higher bandwidth and therefore faster, enabling a quicker response to detected situations, errors, malfunctions, etc., in order to initiate countermeasures or trigger warning signals.The data center can be designed, for example, to transmit only pre-filtered and / or pre-evaluated data to the higher-level process control system, thus significantly reducing the amount of data transmitted and the data to be processed and evaluated at the higher level. The filtering and / or pre-evaluation can be performed intelligently, for example, by incorporating artificial intelligence into the data center. In one embodiment of the field device system according to the invention, the data center is further designed to perform diagnostics, trend analysis, operating state analysis, and / or predictive analysis based on the pre-evaluated and / or pre-filtered data. The processing of the pre-evaluated and / or pre-filtered data takes place directly in the data center, without the need to transmit all collected data from the field devices to the process control system. For example, predictive maintenance and the identification of optimization potential for the field devices and / or the process control system itself can be enabled based on the data. Additionally, predictive analyses can be performed to draw conclusions about a process status, such as process trends, from the data.For example, the data center may have several subunits to distribute computing power across them. These subunits can communicate with each other, particularly via Ethernet APL, and be interconnected via signal transmission. According to an exemplary embodiment of the field device system according to the invention, at least one algorithm is stored on the data center, according to which the received data is sorted, grouped, clustered, and / or evaluated, for example, subjected to a Fourier analysis. Using the algorithm, for example, diagnostic measures, trend analyses, operational status analyses, health score analyses, and, in particular, predictive trend analyses can be performed. For example, it is possible to access the data center either via the process control system or via other data transmission networks, for example, to upload algorithms and / or update the data center and / or to perform troubleshooting. In a further exemplary embodiment of the field device system according to the invention, the data center is also designed to store the pre-evaluated and / or pre-filtered data in a chronologically assigned manner. This prevents data congestion or a slow data transmission rate to a higher-level system, such as the higher-level process control of the process plant, in particular without deleting relevant data. The data can be evaluated continuously, especially simultaneously or periodically, preferably together or sequentially. If a measured value or a series of measurements, encompassing or covering the respective time of the measurement result, is selected and stored with respect to a parameter covered by the data, the data center is designed to directly evaluate such selected data sets or to transmit them to the higher-level system.For example, it is possible for the stored data to be periodically deleted at the data center or at specific times, and / or transferred in advance to another system, such as a storage unit that may be located on a server. This temporal assignment makes it possible to subsequently analyze or detect an event associated with a specific measurement, particularly when it comes to identifying sources of error and / or deriving measures for the future, or even determining predictive interventions to counteract the recurrence of this event. In a further exemplary embodiment of the present invention, the data center is also designed to evaluate the pre-filtered data and transmit the evaluated data to the process control system, or to transmit the pre-filtered data directly to the process control system, wherein, in particular, the evaluation of the transmitted data then takes place in the process control system. For example, this can depend on the amount of data, the data quality, and / or at least one parameter captured by the data. Connecting multiple field devices to the data center, and especially using the Ethernet APL connection, enables the utilization of its increased bandwidth for detailed diagnostics and monitoring of the process plant or a part thereof, encompassing the monitored field devices and, if applicable, sensors. The data center can collect a large volume of data in or near the field, which can then be continuously received, processed, and / or analyzed via Ethernet APL with high temporal resolution. Examples of parameters that can be acquired include process code, control signals, control currents, temperature, supply air pressure or flow rate in a supply air duct, exhaust air pressure or flow rate in an exhaust air duct, image and / or sound signals, or other operationally relevant signals from a field device or other equipment within the process plant. For example, the measured values ​​of the parameters, or their temporal progression, can be compared with stored reference values ​​for monitoring and diagnostic purposes using the data center. The reference values ​​can be defined for a single field device or for a combination of field devices. This could involve, for instance, the acquisition of a parameter along a process path of the process plant via one or more field devices and / or one or more sensors, or even the combination of several data centers for monitoring the entire process plant. This allows multiple field devices to be monitored in a process- and / or function-specific manner. It is also conceivable that new field devices of the same type, such as several control valves of the same type, could be compared with each other over time and / or during the same actuation process using the parameters they have acquired.One key objective is to detect malfunctions and faults in field devices or processes by identifying deviations from a reference value or irregularities in recorded measurements, and / or to identify optimization potential for individual devices within a process. For example, the control valve and / or the data center can be designed to operate in real time. This provides improved opportunities to intervene or optimize processes and process nodes, depending on the typology and networking of the data center units. The field device system according to the invention enables, among other things, a combined evaluation of a portion of the process plant based on data from the field devices connected via the data center, a configuration as a login and authentication point for the modular addition of field devices, and a function as part of a safety circuit for the field devices, whereby the safety functions of all field devices can be coordinated. Furthermore, intelligent filtering or pre-evaluation of field device data to prevent data congestion at a higher-level system, and a special situation-triggered logging function to automatically store relevant data for safety tests or logging depending on the situation, can be easily implemented. In addition, the system allows for the merging of data from other sensors external to the field devices for comprehensive diagnostics.Furthermore, predictive maintenance and the identification of optimization potential for field devices and / or the process can be enabled. Additionally, algorithms can run in the background to perform predictive analyses, drawing conclusions about process status and trends from sensor and actuator data. Multiple data centers can also be used for optimized distribution of computing resources (for example, hardware-based multithreading, multi-core usage, and distribution of computational operations, especially RAM or processing power). According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a field device system is provided for adjusting a process fluid flow in a process engineering plant such as a chemical plant, a power plant, a food processing plant or the like. The field device system comprises several field devices. For example, a field device is a control device, a measuring device, or an actuator. A field device can, for example, be a control valve for adjusting a branch of the process fluid flow. For example, a field device is a control valve or a pump. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. For example, the control valve can be actuated pneumatically, electrically, or hydraulically. The field device can be operated with auxiliary energy, such as pneumatic auxiliary energy, wherein, in particular, a preferably pneumatic actuator can be actuated via a positioner, especially an electropneumatic one.The field device system, and in particular the field device itself, can be either a freestanding or integrated field device capable of handling the fluids encountered during processing in large-scale plants under explosion protection. Generally, field devices are designed to influence, and in particular control and / or regulate, the process fluid flow within the process plant. The field device system further comprises a data center for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices. The sensor data can be acquired by means of at least one sensor separate from the field device, for example, an optical and / or acoustic sensor. The sensor can be, for example, a camera and / or a microphone. The sensor is configured to acquire image and / or sound data. For example, the image and / or sound data may be image and / or sound data attributable to at least one field device. The sensor may also be, for example, an optical microphone according to EP 3 351 838 A1, the content of which is specified herein for the sake of completeness. Furthermore, the field device system according to the invention comprises a wired communication network configured to connect the process control and the individual field devices to the data center for signal transmission. For example, data transmission via the communication network is carried out using Ethernet-APL. Signal transmission between the data center and the higher-level process control can also be based on Ethernet-APL or other communication connections, such as a bus connection, via HART, PROFIBUS, FOUNDATION Fieldbus, or the like. According to a further aspect of the invention, the data center is designed to divide the field devices into groups and to perform a group evaluation of the field devices belonging to the respective group based on the received data. By combining measurement data from several field devices along a process path within the process plant using the data center, it is possible to indirectly obtain information about a field device, in particular a diagnosis or the like, from a field device without its own diagnostic function or with only a rudimentary diagnostic function, for example, valve flaps, pumps, an air supply network, or similar, namely by using the data of neighboring field devices within the group.By combining multiple measurement data sets, especially from locally and / or functionally related field devices, into a single group, the amount of data can be used advantageously to enable meaningful diagnoses that would not be possible using measurement data from a single field device or would require significantly more complex downstream analysis and calculation processes. For example, the data center can be designed to measure pressure and / or flow rates from multiple field devices, such as at the air supply inlets of the field devices, allowing conclusions to be drawn about the condition of the field device, particularly its air supply.Furthermore, it is possible that the data center is designed to perform a diagnosis of a field device designed as a pump, for example via the changing flow resistance at an actuator or the like, a diagnosis of a cooling water supply via several temperature measurements, etc. In an exemplary embodiment of the field device system according to the invention, the data center is further designed to perform diagnostics, trend analysis, operating state analysis, and / or predictive analysis for the group of field devices based on the received data. The processing of the grouped data takes place directly in the data center, without the need to transmit all collected data from the field devices to the process control system. For example, predictive maintenance and the identification of optimization potential for the field devices contained in the process plant and / or the process control system itself can be enabled based on the data. Additionally, predictive analyses can also be performed to draw conclusions about a process status, such as process trends, from the data.For example, the data center may have several subunits to distribute computing power across them. These subunits can communicate with each other, particularly via Ethernet APL, and be interconnected via signal transmission. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a field device system is provided for adjusting a process fluid flow of a process engineering plant, such as a chemical plant, a power plant, a food processing plant or the like. The field device system comprises several field devices. For example, a field device is a control device, a measuring device, or an actuator. A field device can, for example, be a control valve for adjusting a branch of the process fluid flow. For example, a field device is a control valve or a pump. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. For example, the control valve can be actuated pneumatically, electrically, or hydraulically. The field device can be operated with auxiliary energy, such as pneumatic auxiliary energy, wherein, in particular, a preferably pneumatic actuator can be actuated via a positioner, especially an electropneumatic one.The field device system, and in particular the field device itself, can be either a freestanding or integrated field device capable of handling the fluids encountered during processing in large-scale plants under explosion protection. Generally, field devices are designed to influence, and in particular control and / or regulate, the process fluid flow within the process plant. The field device system further comprises a data center for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices. The sensor data can be acquired by means of at least one sensor separate from the field device, for example, an optical and / or acoustic sensor. The sensor can be, for example, a camera and / or a microphone. The sensor is configured to acquire image and / or sound data. For example, the image and / or sound data may be image and / or sound data attributable to at least one field device. The sensor may also be, for example, an optical microphone according to EP 3 351 838 A1, the content of which is specified herein for the sake of completeness. Furthermore, the field device system according to the invention comprises a wired communication network configured to connect the process control and the individual field devices to the data center for signal transmission. For example, data transmission via the communication network is carried out using Ethernet-APL. Signal transmission between the data center and the higher-level process control can also be based on Ethernet-APL or other communication connections, such as a bus connection, via HART, PROFIBUS, FOUNDATION Fieldbus, or the like. According to a further aspect of the invention, the data center is designed to authenticate, based on the received data, whether another field device can be integrated into the communication network. In particular, the data center can act as a registration and / or authentication unit, especially to design the field device system modularly, whereby a check of the field devices to be added and / or further devices in the process plant can be controlled. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a field device system is provided for adjusting a process fluid flow of a process engineering plant, such as a chemical plant, a power plant, a food processing plant or the like. The field device system comprises several field devices. For example, a field device is a control device, a measuring device, or an actuator. A field device can, for example, be a control valve for adjusting a branch of the process fluid flow. For example, a field device is a control valve or a pump. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. For example, the control valve can be actuated pneumatically, electrically, or hydraulically. The field device can be operated with auxiliary energy, such as pneumatic auxiliary energy, wherein, in particular, a preferably pneumatic actuator can be actuated via a positioner, especially an electropneumatic one.The field device system, and in particular the field device itself, can be either a freestanding or integrated field device capable of handling the fluids encountered during processing in large-scale plants under explosion protection. Generally, field devices are designed to influence, and in particular control and / or regulate, the process fluid flow within the process plant. The field device system further comprises a data center for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices. The sensor data can be acquired by means of at least one sensor separate from the field device, for example, an optical and / or acoustic sensor. The sensor can be, for example, a camera and / or a microphone. The sensor is configured to acquire image and / or sound data. For example, the image and / or sound data may be image and / or sound data attributable to at least one field device. The sensor may also be, for example, an optical microphone according to EP 3 351 838 A1, the content of which is specified herein for the sake of completeness. Furthermore, the field device system according to the invention comprises a wired communication network configured to connect the process control and the individual field devices to the data center for signal transmission. For example, data transmission via the communication network is carried out using Ethernet-APL. Signal transmission between the data center and the higher-level process control can also be based on Ethernet-APL or other communication connections, such as a bus connection, via HART, PROFIBUS, FOUNDATION Fieldbus, or the like. According to a further aspect of the invention, the data center is designed to output a safety control signal individually for each field device based on the received data. For this purpose, the communication network can have a safety control circuit into which the data center can be integrated. The data center can be designed to perform safety functions with respect to the field devices connected to it. For example, the data center can be configured to output coordinated safety control signals for several of the field devices and / or to selectively control at least one or more of the field devices in order to carry out safety control measures.For example, the data center can be configured to monitor signal streams from field devices designed as control valves, which are variable via limit contacts or control a solenoid valve. In the event of a triggering event or key event, such as the activation of a limit contact or a non-opening solenoid valve, a safety control signal can be output. It is also possible for the respective control valve to switch other field devices connected to the data center, such as control valves and / or pumps, into a safe position or safety mode via the data center. According to an exemplary embodiment of the control valve according to the invention, the safety control signal comprises an operating state, such as an open or closed state, a safety operating mode, a safety routine stored, in particular, on the data center or on the respective field device, and / or an alarm. For example, the respective field device is closed and / or activated in a safety mode for field devices downstream in the process direction. For example, the data center can be designed to acquire additional diagnostic measures and / or more frequent measurement data for such field devices. For example, the data center is also designed to continue monitoring a field device that has been moved into a closed state after it has entered the closed state. According to a further exemplary embodiment of the field device system according to the invention, the data center is also designed to identify for each field device whether it has received a safety control signal and, depending on this, to decide whether the respective field device is bypassed and / or a backup plant line is activated. This prevents damage to other components and / or the entire process plant, or ensures that the overall process is not unnecessarily impaired and that the process plant remains operational. In another exemplary embodiment of the field device system according to the invention, the data center is further designed to resolve the received data temporally. According to an exemplary further development, the data center is also designed to compare the received data from several field devices simultaneously. This allows for situation-specific responses, particularly because the random event can be confirmed by an additional parameter, deemed non-critical, or a cause identified, each of which may require a different safety function. For example, the field device system can be designed such that a leak in the actuator of a control valve is detected if there is a sudden drop in exhaust air pressure and a simultaneously accelerating change in the stroke of a field device designed as a control valve.The system can also be designed to initiate, in addition to the closing action of the respective field device, the closing and / or emergency switching of a subsequent field device (designed as a control valve) and a control valve located downstream in the process direction. A further advantage is that the error messages from several field devices can be considered together, both to reduce the number of error messages and to derive or initiate overarching safety and / or corrective measures or interventions. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a field device system is provided for adjusting a process fluid flow of a process engineering plant, such as a chemical plant, a power plant, a food processing plant or the like. The field device system comprises several field devices. For example, a field device is a control device, a measuring device, or an actuator. A field device can, for example, be a control valve for adjusting a branch of the process fluid flow. For example, a field device is a control valve or a pump. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. For example, the control valve can be actuated pneumatically, electrically, or hydraulically. The field device can be operated with auxiliary energy, such as pneumatic auxiliary energy, wherein, in particular, a preferably pneumatic actuator can be actuated via a positioner, especially an electropneumatic one.The field device system, and in particular the field device itself, can be either a freestanding or integrated field device capable of handling the fluids encountered during processing in large-scale plants under explosion protection. Generally, field devices are designed to influence, and in particular control and / or regulate, the process fluid flow within the process plant. The field device system further comprises a data center for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices. The sensor data can be acquired by means of at least one sensor separate from the field device, for example, an optical and / or acoustic sensor. The sensor can be, for example, a camera and / or a microphone. The sensor is configured to acquire image and / or sound data. For example, the image and / or sound data may be image and / or sound data attributable to at least one field device. The sensor may also be, for example, an optical microphone according to EP 3 351 838 A1, the content of which is specified herein for the sake of completeness. Furthermore, the field device system according to the invention comprises a wired communication network configured to connect the process control and the individual field devices to the data center for signal transmission. For example, data transmission via the communication network is carried out using Ethernet-APL. Signal transmission between the data center and the higher-level process control can also be based on Ethernet-APL or other communication connections, such as a bus connection, via HART, PROFIBUS, FOUNDATION Fieldbus, or the like. According to a further aspect of the invention, the data center has a memory and is designed to perform a logging function, particularly one triggered by the situation and / or user, in which safety test-specific data or a log is automatically stored in the memory based on the received data. The logging function makes it possible to store relevant data for the respective safety circuit or for logging purposes, depending on the situation. In particular, the data center can be designed so that the storage occurs automatically. It is particularly advantageous if the communication network operates on an Ethernet APL basis to ensure a particularly comprehensive and time-accurate representation of the field devices via the acquired parameters. The data center can be designed to enable the compilation of this data over the duration of the safety test or the monitoring period.It is possible for the data center to subsequently transmit all data without loss due to a limited bandwidth, particularly gradually, to a higher-level system, such as a higher-level process control system. Furthermore, the data center can be designed to test multiple field devices and / or sensors sequentially or simultaneously. According to an exemplary embodiment of the present invention, the data center is further configured to perform a safety and / or control test based on the safety test-specific data or the logging. According to a further exemplary embodiment, the data center is further configured to transmit safety and / or control data generated during the safety and / or control test to the process control system. In this respect, the system can be designed to distribute the necessary steps in data acquisition, processing, and / or evaluation. According to a further exemplary embodiment of the present invention, the data center is also configured to control other devices of the process plant depending on the safety and / or control data. For example, the system can be designed such that other devices of the process plant are controlled by the data center during a safety test of one or more of the field devices in order to prevent any impact on the process, for example by putting devices not affected by the safety test into a passive mode or a safety operating mode, or by switching them off. For example, the system can be designed such that a field device configured as a control valve or as a safety fitting, which is located downstream of the field device to be tested in the process direction, is closed, in particular automatically.In particular, it may be provided that when such a security test is carried out using the data center, one or all devices connected to the data center are automatically selected. The test can be triggered via bus communication and / or, in particular, by actively activating a data center. In a further exemplary embodiment of the present invention, the field device system according to the invention further comprises a process controller that controls the multiple field devices. The process controller can be connected to the multiple field devices, in particular via the communication network, for example via Ethernet-APL. The connection between the process controller and the data center can also be based on Ethernet-APL. Furthermore, it is conceivable that the connection between the data center and the higher-level process controller is established via a bus connection, for example via HART, PROFIBUS, FOUNDATION Fieldbus, or the like. By linking the process control system with the data center, information about the process plant and its field devices can be exchanged and used globally for process control. This information can also be fed back into the data center for evaluation and / or direct control by the control unit itself. This provides a highly flexible and efficient diagnostic capability for the process plant. In an exemplary embodiment of the field device system according to the invention, the data center is configured to communicate with sensors and / or the multiple field devices independently of the process control system, to transmit and / or evaluate data, and, in particular, to control at least one of the multiple field devices based on the received data, especially the field device-specific diagnostics. In other words, it is possible for the data center to operate independently, i.e.,Without a command from the higher-level process control, control interventions for at least one of the field devices are initiated, particularly based on diagnoses and evaluations derived from the generated and received data. This makes the system exceptionally responsive. Furthermore, increased data transfer and global process control are avoided, thus preventing additional processing demands on the latter. According to another exemplary embodiment, the process control system is configured to act on the safety and / or control data of both devices in the process plant. For example, the process control system may be configured to override control commands from the data center and replace them with its own control signals. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method for adjusting a process fluid flow by means of a field device system comprising several field devices, such as a control valve and / or a pump, which can be controlled by a process controller, is provided to a process plant, such as a chemical plant, a power plant, a food processing plant, or the like. The field device system can be configured according to any of the aspects or exemplary embodiments described above. The field device system according to the invention can be referred to as a control valve system if at least one field device is configured as a control valve. In other words, a control valve system according to the invention comprises at least one field device configured as a control valve and further field devices. According to the method according to the invention, field device-specific data and / or sensor data assigned to and / or assignable to the field devices are received by a data center, pre-evaluated and / or pre-filtered by the data center, and the pre-evaluated and / or pre-filtered data are transmitted to the process control system by the data center. Because the amount of data is very high, especially in modern process plants with a large number of sensors, field devices, and recorded measurement data or measured values, prior art field device systems tended to overload the signal transmission equipment. By pre-filtering and / or pre-filtering the data, the data transmission equipment is no longer overloaded. Pre-evaluation reduces the amount of data to be transmitted, thus minimizing the risk of overload. Furthermore, this reduced data volume can be transmitted over a higher bandwidth and therefore faster, allowing for a quicker response to detected situations, errors, malfunctions, etc., in order to initiate countermeasures or trigger warning signals. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method for adjusting a process fluid flow by means of a field device system comprising several field devices, such as a control valve and / or a pump, which can be controlled by a process controller, is provided to a process plant, such as a chemical plant, a power plant, a food processing plant, or the like. The field device system according to the invention can be referred to as a control valve system if at least one field device is configured as a control valve. In other words, a control valve system according to the invention comprises at least one field device configured as a control valve and further field devices. In the method according to the invention, field device-specific data and / or sensor data assigned to and / or assignable to the field devices are received by means of a data center. The field device-specific data and / or sensor data assigned to the field devices are then communicated via cable between the process controllers and the individual field devices by means of a data center. Furthermore, the field devices are divided into groups, and a group evaluation of the field devices belonging to the respective group is carried out based on the received data. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method for adjusting a process fluid flow by means of a field device system comprising several field devices, such as a control valve and / or a pump, which can be controlled by a process controller, is provided to a process plant, such as a chemical plant, a power plant, a food processing plant, or the like. The field device system according to the invention can be referred to as a control valve system if at least one field device is configured as a control valve. In other words, a control valve system according to the invention comprises at least one field device configured as a control valve and further field devices. According to the inventive method, field device-specific data and / or sensor data assigned to and / or assignable to the field devices are received by means of a data center. The field device-specific data and / or sensor data assigned to the field devices are communicated via cable between the process control system and the individual field devices by means of a data center. Furthermore, based on the received data, it is authenticated whether another field device can be integrated into the communication network. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method for adjusting a process fluid flow by means of a control valve, comprising several field devices, such as a control valve and / or a pump, which are controllable by a process control system and have a safety mode, is provided to a process plant, such as a chemical plant, a power plant, a food processing plant, or the like. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. According to the inventive method, field device-specific data and / or sensor data assigned to and / or assignable to the field device are received by means of a data center. Furthermore, a safety control signal is individually output for each field device based on the received data. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method for adjusting a process fluid flow by means of a field device system comprising several field devices, such as a control valve and / or a pump that can be controlled by a process controller, is provided to a process plant, such as a chemical plant, a power plant, a food processing plant, or the like. The field device system according to the invention can be referred to as a control valve system if at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. In the method according to the invention, field device-specific data and / or sensor data assigned to and / or assignable to the field devices are received by means of a data center. The field device-specific data and / or sensor data assigned to the field devices are communicated via cable between the process control and the individual field devices by means of a data center. Furthermore, according to the invention, a logging function, in particular triggered by the situation and user, is implemented, in which safety test-specific data or a log is automatically saved based on the received data. According to a further aspect of the invention, a method for operating a field device system configured according to one of the aspects or exemplary embodiments described above is provided. The field device system according to the invention can be referred to as a control valve system if at least one field device is configured as a control valve. In other words, a control valve system according to the invention comprises at least one field device configured as a control valve and further field devices. According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a process plant, such as a chemical plant, a power plant, a food processing plant, or the like, is provided with a field device system according to one of the previously described aspects or exemplary embodiments. The field device system according to the invention can be referred to as a control valve system, provided that at least one field device is designed as a control valve. In other words, a control valve system according to the invention comprises at least one field device designed as a control valve and further field devices. Preferred embodiments are specified in the dependent claims. Further features, properties and advantages of the invention are made clear by the following description of preferred embodiments, in which: Fig. 1 shows a schematic principle sketch of a process engineering plant with an exemplary embodiment of a field device system according to the invention; and Fig. 2 shows a flow diagram of an exemplary embodiment of a method according to the invention. To simplify readability, the same or similar reference symbols are used in the following description of preferred embodiments for the same or similar components. Fig. 1 shows an exemplary process plant 1. The process plant 1 can be, for example, a chemical plant, a power plant, a food processing plant, or the like. The process plant 1 comprises as essential components a process control unit 3, a safety control unit 5, a data center (example: diagnostic box 7), and a variety of field devices 9. The process fluid flow in the process plant 1 can be adjusted using the field devices 9. The field devices 9 can, for example, be actuators. The process plant 1 also has a variety of sensors for acquiring measurement data. The sensors can either be directly assigned to a field device 9, such as sensor 11 in Fig. 1, or acquire data independently of the individual field devices 9, such as sensor 13 in Fig. 1. The process control unit 3 controls the process plant 1 and includes, for example, an engineering system 15, a control unit 17, and an asset management system 19. The process control unit 3 is connected to the diagnostic box 7 via a line 21. Line 21 can be used simultaneously for power supply and data transmission. In other words, the simultaneous transmission of multiple signals is possible via line 21. Specifically, line 21 is an Ethernet APL line. An APL power switch 23, which provides power, is interposed between the process control unit 3 and the diagnostic box 7. The safety controller 5 is part of a safety circuit that includes the safety controller 5 and all devices of the process plant 1. The safety controller 5 is capable of controlling the devices independently of the process controller 3. The safety controller 5 is also connected to the diagnostic box 7 via a line 25, which can also be an Ethernet APL line. The process controller 3 and the safety controller 5 together form a higher-level unit for controlling and / or regulating the process plant 1. The diagnostic box 7 can additionally be connected to a cloud (not shown in Fig. 1), which can then also be part of the higher-level unit for controlling the process plant 1 and / or allow access to the acquired data and / or the system controller 3. In the embodiment shown in Fig. 1, the field devices 9 are arranged in three clusters 27, 29, 31, each containing several field devices 9. Data transmission is possible between the field devices 9 of a cluster 27, 29, 31; in other words, the field devices 9 of a cluster are interconnected via a communication network. Furthermore, in the embodiment shown in Fig. 1, data transmission is possible between the clusters 27, 29, 31 and the diagnostic box 7. For this purpose, the field devices 9 are connected to each other and to the diagnostic box 7 via trace data lines 33, which are preferably Ethernet APL lines. To connect the lines 33 of the individual field devices 9 collectively to the diagnostic box 7, an APL switch 35 is arranged between each cluster 27, 29, 31 and the diagnostic box 7 to aggregate the lines 33. The lines 33 also provide electrical shielding, ensuring that no ignitable energy is reached and that the energy remains reliably below an ignitable level. This allows the field devices 9 and the APL switches 35 to be used in potentially explosive atmospheres of Zones 1 and 2. In Fig. 1, the field device cluster 29 is located in Zone 1, indicated by reference numeral 37, and the field device cluster 31 is located in Zone 2, indicated by reference numeral 39. A connection between the field device clusters 27, 29, 31 and the process controller 3 and / or a connection between the field device clusters 27, 29, 31 and the safety controller 5 is also possible via an additional parallel line. In Fig. 1, for example, the field device cluster 27 is directly connected to the process controller 3 via a line 41 and an APL switch 35, so that the process controller 3 is also directly connected to the field device cluster 27 in parallel with the connection via the diagnostic box 7. Similarly, in Fig. 1, the field device cluster 27 is also directly connected to the safety controller 5 via an additional line 43, but in this case, no additional APL switch is provided; instead, line 43 connects the safety controller 5 to the APL switch 35, which is provided between the field device cluster 27 and the diagnostic box 7.It is clear that, alternatively, line 43 can also have an additional APL switch, and that, alternatively, line 41 can also be connected to APL switch 35 between field device cluster 27 and diagnostic box 7. It is also clear that additional lines can be provided for the other field device clusters 29 and 31, connecting the respective field device clusters 29 and 31 directly to the process controller 3 and / or the safety controller 5, as exemplified by line 45 between the safety controller 5 and the other field device clusters 29 and 31. According to one aspect of the invention, the diagnostic box 7 is designed to pre-evaluate and / or pre-filter the received data and to transmit the pre-evaluated and / or pre-filtered data to the process control 3 and / or to perform further functions / measures within the process plant 1. Fig. 2 shows a flowchart of an exemplary embodiment of a method according to the invention for adjusting a process fluid flow using a field device system, particularly one designed according to the invention, in a process plant. In the method according to the invention, field device-specific data and / or sensor data assigned to the field devices are first received by means of a data center (step 101). The data is then pre-evaluated and / or pre-filtered by the data center (step 103). Subsequently, the pre-evaluated and / or pre-filtered data is transmitted to the process control system via the data center (step 105). The method according to the invention can also be designed or described as a monitoring method, since the aforementioned steps enable monitoring, in particular diagnostics and fault detection, of field devices within the process plant. In an exemplary implementation, in addition to comparing recorded parameters on several field devices and / or sensors via the data center, events detected in recorded parameters can be interpreted via other recorded parameters that are also received / evaluated via the data center. The temporal resolution of the parameters is particularly advantageous, as the various parameters can be compared simultaneously. This allows for situation-specific responses, since the respective event can be confirmed by additional parameters, deemed non-critical, or its cause identified, each of which may require a different safety function. For example, a sudden drop in exhaust pressure combined with a rapidly changing stroke of a control valve can indicate a leak in the actuator of the control valve. In addition to closing the respective control valve, this can trigger the closing of a subsequent control valve or another safety device. Alternatively or additionally, the data center is configured to intelligently filter and / or pre-evaluate acquired / received measurement data, in particular to evaluate and / or store relevant events for individual parameters. Preferably, measured values ​​for several / all parameters are stored if an event is detected for at least one parameter. Preferably, all measured values ​​are stored / cached with a time stamp. This prevents data congestion at the higher-level process control system, especially without deleting relevant data. For this purpose, the parameters of the field devices and sensors are evaluated continuously, especially simultaneously, or periodically, preferably together or sequentially, by the data center.If an event is detected for at least one parameter, at least one measured value or a series of measurements covering the respective time of the event is selected and stored for a parameter-specific selection of parameters or for all parameters. It is conceivable that such selected data sets could be evaluated directly by the data center or transferred to a higher-level system, such as the process control system of the process plant. Preferably, the remaining data is periodically deleted from the data center or transferred to another device, such as a server, and then deleted. Special safety tests are required, particularly for the certification of devices or system components, but also for regular inspections. The data center could feature a situation- or user-triggered logging function to automatically record relevant data for the respective safety test or log, depending on the situation. The Ethernet APL connection enables a particularly comprehensive and time-resolved mapping of the devices via the recorded parameters. The data center allows this data to be compiled over the duration of the safety test or inspection. All data can then be transferred subsequently, without data loss due to bandwidth limitations, to a higher-level system or evaluation device. It is conceivable that field devices and / or sensors could be tested sequentially or simultaneously via the data center.Preferably, the data center controls the respective device(s) to be tested in order to perform the test. It is conceivable that other devices in the process plant could be controlled by the data center for such a safety test in order to prevent any impact on the process. For example, a control valve or a safety fitting would be automatically closed downstream of the control valve or safety fitting during the performance of safety tests. Preferably, such a safety test is performed automatically by the data center for a selection of or all devices connected to the data center, whereby the test can be triggered directly via bus communication and / or by actuating an element on the data center. By aggregating measurement data from multiple devices along a process path via a central data center, it is conceivable to indirectly diagnose devices without their own diagnostic functions or with only rudimentary diagnostic functions, such as dampers, pumps, the supply air network, etc., preferably using data acquired from surrounding field devices that are directly or indirectly connected to the respective device. By aggregating the measurement data in the central data center(s), the wealth of data can be advantageously utilized to enable diagnoses that would not be possible using measurement data from a single device. For example, it is conceivable to measure pressures and / or flow rates at the supply air inlets of multiple field devices, allowing conclusions to be drawn about the condition of the supply air system.Other examples include diagnosing a pump via a changing flow resistance at an actuator or similar device, diagnosing a cooling water supply via multiple temperature measurements, etc. Such a diagnosis, and preferably a response to the resulting diagnostic findings, can be used directly in the field via the data center. The features disclosed in the figures and claims in the foregoing description can be important for the realization of the invention in its various embodiments, both individually and in any combination. Reference symbol list 1 Process plant 3 Process control 5 Safety control 7 Data center / Diagnostic box 9 Field device 11, 13 Sensor 15 Engineering system 17 Controller 19 Asset management system 21, 25 Line 23 APL power switch 27, 29, 31 Cluster 33 Line 35 APL switch 37 Zone 1 39 Zone 2 41, 43, 45 Line 101 Process step Data acquisition 103 Process step Data pre-filtering and / or pre-evaluation 105 Process step Data transmission

Claims

Field device system for adjusting a process fluid flow of a process plant (1), such as a chemical plant, a power plant, a food processing plant or the like, comprising: - several field devices (9), such as a control valve and / or a pump, which can be controlled by a process controller (3); and - a data center (7) for receiving field device-specific data and / or sensor data assigned to and / or assignable by the field devices (9); wherein the data center (7) is designed to pre-evaluate and / or pre-filter the received data and to transmit the pre-evaluated and / or pre-filtered data to the process controller (3); wherein the data center (7) is further designed to perform a diagnosis, a trend analysis, an operating state analysis and / or a predictive analysis based on the pre-evaluated and / or pre-filtered data. Field device system according to claim 1, wherein at least one algorithm is stored on the data center (7) according to which the received data is sorted, grouped, clustered and / or evaluated, for example subjected to a Fourier analysis. Field device system according to one of the preceding claims, wherein the data center (7) is further designed to store the pre-evaluated and / or pre-filtered data in a temporally assigned manner. Field device system according to one of the preceding claims, wherein the data center (7) is further designed to evaluate the pre-filtered data and to transmit the evaluated data to the process control (3) or to transmit it directly to the process control (3). The field device system according to one of the preceding claims further comprises: - a wired communication network configured to connect the process control (3) and the individual field devices (9) to the data center (7) for signal transmission; wherein the data center (7) is further configured to divide the field devices (9) into groups and to perform a group evaluation of the field devices (9) belonging to the respective group based on the received data. Field device system according to claim 5, wherein the data center (7) is further designed to perform a diagnosis, a trend analysis, an operating condition analysis and / or a predictive analysis for the group of field devices (9) based on the received data. Field device system according to one of the preceding claims further comprising: - a wired communication network configured to connect the process control (3) and the individual field devices (9) to the data center (7) for signal transmission; wherein the data center (7) is further configured to authenticate, on the basis of the received data, whether another field device (9) can be integrated into the communication network. A field device system according to one of the preceding claims further comprising: - several field devices (9), such as a control valve and / or a pump, which can be controlled by a process controller (3) and have a safety mode; - a wired communication network which is configured to connect the process controller (3) and the individual field devices to the data center (7) for signal transmission; wherein the data center (7) is designed to output a safety control signal individually for each field device (9) based on the received data. Field device system according to claim 8, wherein the safety control signal has an operating state, such as an opening or closing state, a safety operating mode, a safety routine stored in particular on the data center (7) or the respective field device (9) and / or an alarm. Field device system according to claim 8 or 9, wherein the data center (7) is further designed to identify for each field device (9) whether it has received a safety control signal and, depending on this, to decide whether the respective field device (9) is bypassed and / or a backup system string is activated. Field device system according to one of the preceding claims, wherein the data center (7) is further designed to resolve the received data temporally, wherein in particular the data center (7) is further designed to compare the received data of the several field devices at the same time. Field device system according to one of the preceding claims further comprising: - a wired communication network configured to connect the process control (3) and the individual field devices (9) to the data center (7) for signal transmission; wherein the data center (7) has a memory and is designed to perform a logging function, in particular situation- and / or user-triggered, in which, based on the received data, safety test-specific data or a log is stored, in particular automatically, on the memory. Field device system according to claim 12, wherein the data center (7) is further configured to perform a safety and / or control test on the basis of the safety test-specific data or the logging, wherein the data center (7) is further configured to transmit safety and / or control data generated during the safety and / or control test to the process control. Field device system according to claim 13, wherein the data center (7) is further configured to control other devices of the process plant depending on the safety and / or control data. Field device system according to one of the preceding claims, further comprising a process control system (3) controlling the multiple field devices (9). Field device system according to claim 15, if dependent on claim 13 or 14, wherein the process control (3) is configured to control further devices of the process plant (1) depending on the safety and / or control data. Method for adjusting a process fluid flow using a field device system comprising several field devices (9), such as a control valve and / or a pump, which can be controlled by a process controller (3), in a process plant (1), such as a chemical plant, a power plant, a food processing plant or the like, in which field device-specific data and / or sensor data assigned to and / or assignable to the field devices (9) are received by means of a data center (7), pre-evaluated and / or pre-filtered by the data center (7) and in which the pre-evaluated and / or pre-filtered data are transmitted to the process controller (3) by means of the data center (7); wherein a diagnosis, a trend analysis, an operating state analysis and / or a predictive analysis is carried out by means of the data center (7) on the basis of the pre-evaluated and / or pre-filtered data. Method according to claim 17, wherein the field device-specific data and / or sensor data assigned to the field devices (9) are communicated via cable between the process control (3) and the individual field devices (9) by means of a data center (7), the field devices (9) are divided into groups and a group evaluation of the field devices (9) belonging to the corresponding group is carried out on the basis of the received data. Method according to claim 17 or 18, wherein the field device-specific data and / or sensor data assigned to the field devices (9) are communicated via cable between the process control and the individual field devices (9) by means of a data center (7) and, based on the received data, it is authenticated whether another field device (9) can be integrated into the communication network. Method according to one of claims 17 to 19, wherein the field device system comprises several field devices (9), such as a control valve and / or a pump, which can be controlled by a process control (3) and have a safety mode, wherein a safety control signal is individually output for each field device (9) based on the received data. Method according to one of claims 17 to 20, wherein the field device-specific data and / or sensor data assigned to the field devices (9) are communicated via cable between the process control (3) and the individual field devices (9) by means of a data center (7) and a logging function, in particular situation- and / or user-triggered, is executed, in which safety test-specific data or a log is saved automatically on the basis of the received data. Method according to one of claims 17 to 21 for operating a field device system according to one of claims 1 to 16. Process plant (1), such as a chemical plant, a power plant, a food processing plant, or the like, comprising a field device system according to any one of claims 1 to 16.

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