System for determining the time of events that have occurred in an industrial plant

Abstract

System for determining the event times of events that have occurred in an industrial plant (12), comprising an automation device (14) of the industrial plant (12) which has industrial plant functionality and is configured to detect an event relating to the industrial plant (12) and to store event information (16) and time information (18) associated with the event information (16) in an event log (20); and a readout device (40) which has a current time and is configured to read the event log (20) of the automation device (14), wherein the readout device (40) and / or the automation device (14) is further configured to record a readout time and, based on the readout time and the time information (18) from the event log (20), to determine a relative time of the event in relation to the readout time and to assign it to the event information (16).

Description

[0001] The invention relates to a system for determining the time of events that have occurred in an industrial plant.

[0002] Historically, many machines and systems operate without a connection to a central time server, yet they still record events, such as malfunctions, in their logs, assigning them timestamps. This leads to the problem that the recorded timestamps often do not correspond to the actual real time. When these logs are read, a discrepancy arises between the recorded times and the actual sequence of events. This asynchronicity between the recorded timestamp and actual time significantly hinders the traceability and evaluation of the log data.

[0003] Even if the system has access to a time server, discrepancies can still occur. Most time servers use Network Time Protocol (NTP), which enables time synchronization with Coordinated Universal Time (UTC). Only with additional information, particularly about the time zone and daylight saving time, can a local time be determined. If the time server settings are incorrect, discrepancies between the protocol and the local time can also occur. Alternatively, a simplified protocol (Simple Network Time Protocol, SNTP) can be used for synchronization. With SNTP, local clocks are synchronized with a central clock in the machine or system. The clock on the machine can then be easily monitored.A quick glance at the machine's time and your own watch is enough to immediately identify the problem. However, during remote maintenance across time zones, it's often not obvious that the machine's clock is malfunctioning.

[0004] The object of the invention is therefore to solve the above-mentioned problems known from the prior art and to provide a technically simple and error-free system for evaluating time-stamped event data.

[0005] The task is solved by a system for determining the event times of events occurring in an industrial plant. The system comprises an automation device within the industrial plant, which has plant-specific functionality and is configured to record events related to the plant and store event information, along with a corresponding time stamp, in an event log. Furthermore, the system includes a readout device, which has a current clock and is configured to read the event log of the automation device. The readout device and / or the automation device is configured to record a readout time and, based on this readout time and the time stamp from the event log, determine a relative time of the event with respect to the readout time and assign this relative time to the event information.

[0006] The basic idea of ​​the invention is to process the event times at which the recorded events occurred as relative times. These relative times define the event times relative to the readout time. In other words, the times specified in a log of the automation device, which are referenced to the time of the automation device, are converted to the time of readout at the time of readout. To illustrate, an event X might, for example, be 35 minutes in the past relative to the readout time. To obtain the absolute time, the time of the readout device can be used as a reference.

[0007] This configuration enables a particularly reliable and flexible evaluation of event times, independent of continuous or error-free synchronization of all system clocks. The traceability and reproducibility of event times are thus significantly improved.

[0008] The relative time can generally be determined by the reading device or the automation device itself, as soon as both devices are connected and the reading process is started.

[0009] The determined relative time can then be assigned to the respective event and stored in the event log or a new log. In principle, the determined relative time can be stored in the event log in addition to, or instead of, the original time information.

[0010] The automation device can be, for example, a controller, in particular a programmable logic controller (PLC), an infrastructure device such as a switch, a fieldbus device, a drive system, an industrial PC (IPC), a sensor or an actuator.

[0011] The reading device is, for example, a laptop, a cloud, a computer, a smartphone, or a similar device.

[0012] One aspect of the invention provides that the automation device is configured to operate independently of a network, in particular independently of a network with access to an NTP server. For example, the automation device is configured to operate independently of the internet, in particular to capture events and store them in the event log.

[0013] This enables operation independent of a permanent network connection. The logging and subsequent correct evaluation of events is also guaranteed in stand-alone or temporarily unconnected systems, system components, or individual machines.

[0014] Furthermore, the automation device can be configured to determine the time information relative to a reference point and store it in the event log. The reference point could be, for example, the time at which the automation device was last started or reset.

[0015] Using a flexible reference point allows for a consistent time base even after system restarts or resets. This ensures that all recorded events remain analyzable within a consistent time structure.

[0016] In another version, the automation device has an internal clock configured to provide an absolute timestamp for each recorded event, which is stored as time information for the respective event in the event log.

[0017] The internal clock and the generation of absolute timestamps allow for the simple and highly precise generation of consistent initial time information for the recorded events. Additionally, system time errors or drifts can be easily detected and corrected.

[0018] Another aspect of the invention provides that the readout device and / or the automation device is configured to calculate a correction factor based on information about a time change of the automation device's internal clock and to store this correction factor in the event log. Alternatively or additionally, the readout device and / or the automation device can also be configured to determine the relative time of the event with respect to the readout time, taking the correction factor into account.

[0019] This allows negative effects of time changes or manual clock corrections to be systematically eliminated, further increasing the accuracy of event time recording and processing.

[0020] It is also conceivable that the reading device is configured to determine, based on the reading time and at least one other communication time at which it communicates with the automation device, a deviation of the automation device's internal clock from the current time, and to correct the relative time and / or the speed of the internal clock based on the detected deviation. Alternatively or additionally, the reading device can also be configured to issue a message if the deviation exceeds a predefined limit.

[0021] This enables both automatic error detection and, if necessary, automatic correction or notification in case of excessive deviations, which in turn improves overall system stability.

[0022] Another aspect is that the reading device is configured to synchronize the internal clock of the automation device with the current time, particularly using an NTP protocol.

[0023] Synchronizing the device clocks minimizes time deviations and significantly increases the accuracy of absolute and relative time determination, especially over longer periods of use.

[0024] In another version, the readout device is configured to generate a temporary clock in the automation device for the purpose of compiling the event log and / or determining relative time.

[0025] This allows for on-demand, targeted time tracking solely for the duration of the log compilation and / or log retrieval process. No permanent changes to the device clock are required, thus preventing disruptions to ongoing operation.

[0026] Another aspect stipulates that the automation device is configured to generate a temporary clock in the readout device, in particular using an NTP protocol, and that the readout device is configured to determine a deviation of the time of the temporary clock from the current time.

[0027] The reading device can then incorporate the deviation into the calculation of the relative or real time of the events. This increases traceability and accuracy, even in distributed systems.

[0028] To simplify the comparability and transferability of the recorded time information of the logged events into international or standardized time systems, the readout device can also be configured to determine, based on the relative time, a time referenced to a standardized time system, in particular Coordinated Universal Time (UTC), at which the event occurred. This improves the system's usability, especially for global maintenance and analysis tasks across different time zones.

[0029] It is also conceivable that the reading device is configured to determine a first time referenced to the standardized time system at the location of the automation device and to determine a second time referenced to the standardized time system at the location of the reading device if the automation device and the reading device are located in different time zones of the standardized time system.

[0030] This enables both on-site staff and remote service personnel to clearly and comprehensibly assign events to a specific time. The system thus supports efficient collaboration across time zones.

[0031] Further features and advantages of the invention will become apparent from the following description and from the accompanying drawings, to which reference is made below. The drawings show: - Fig. 1 A schematic representation of a system according to the invention for determining the event times of events that have occurred in an industrial plant according to an exemplary embodiment.

[0032] In Fig. Figure 1 shows an embodiment of a system 10 according to the invention, which can be used in an industrial plant 12 to determine event times.

[0033] System 10 includes an automation device 14 of the industrial plant 12, which has industrial plant functionality and is configured to record events relating to the industrial plant 12 and to store event information 16 and time information 18 associated with each event information 16 in an event log 20.

[0034] In the example shown, the automation device 14 is a fieldbus module 22 that is connected to sensors 24 of a machine 26 of the industrial plant 12, via which it can acquire event information 16, for example, information about malfunctions or errors that have occurred in the machine 26. Furthermore, the automation device 14 is connected to actuators 28 of the machine 26, via which it can control functions of the machine 26.

[0035] This is of course not to be understood as a limitation. Other types of automation devices 14 can also be used in the system 10 according to the invention for acquiring event information 16, for example controllers, in particular programmable logic controllers (PLCs), switches or drive systems.

[0036] The in Fig. The automation device 14 shown comprises a computing unit 30 with which it can process the recorded event information 16 and / or control the actuators 28, and a memory 32 for storing the recorded event information 16. Furthermore, the automation device 14 has an internal clock 34 which is configured to provide an absolute timestamp 36 for each recorded event, which is stored as time information 18 for the respective event in the event log 20.

[0037] In the illustrated embodiment, the machine 26 and the automation device 14 are configured to operate separately from the industrial plant 12's network 38, specifically separately from the internet and without NTP server access. In this state, the automation device 14 can record events and store the corresponding event information 16, along with the associated time information 18, in the event log 20. Such isolated operation is particularly advantageous when a high level of security against unauthorized access is required or when the machine 26 cannot be integrated into the network 38 due to compatibility issues.

[0038] When an event occurs, for example a malfunction of machine 26, the automation device 14 uses its internal clock 34 to record the time and stores the event information 16 together with a corresponding absolute timestamp 36 in the event log 20. However, since discrepancies can occur between the internal clock 34 and real time during isolated operation, it is not guaranteed that the absolute timestamp 36 indicates the actual time at which the event in question actually took place.

[0039] Alternatively, instead of the absolute timestamp 36, the time information 18 of the recorded event can be recorded relative to a reference point and stored in the event log 20. The reference point could be, for example, the time at which the automation device 14 was last started or reset, or the time at which the memory 32 was last cleared. Each event is then stored in temporal relation to this reference point. Even in this case, the stored information alone does not immediately reveal when the recorded events actually occurred.

[0040] To solve this problem, the following measures are included: Fig. 1 System 10 shown is a readout device 40 which has a current time and is configured to read the event log 20 of the automation device 14.

[0041] A laptop or other mobile device, such as a smartphone, can be used as the reading device 40. With a suitable network connection, a computer, especially a cloud computer, can also be used as the reading device 40.

[0042] In the embodiment, the readout device 40 is configured to record a readout time and, based on the readout time and the time information 18 from the event log 20, to determine relative times of the recorded events in relation to the readout time and to assign them to the respective event information 16.

[0043] To put it figuratively, an event might lie, for example, one hour in the past relative to the time of the data retrieval. In this case, a value of one hour is determined as the relative time for the event in question, thus creating a reference to the actual current time via the known retrieval time.

[0044] To accurately determine the readout time, the readout device 40 has a clock 42. In the exemplary embodiment, the readout device 40, or rather its clock 42, is connected to a public NTP server 44 and synchronized via NTP protocols 46. This ensures that the readout time, and thus also the relative times, can always be determined correctly.

[0045] Alternatively or additionally, the automation device 14 itself can be configured to determine relative times of the recorded events based on the readout time and the time information 18 from the event log 20, and to assign these relative times to the respective event information 16. For this purpose, the readout device 40 can, for example, transmit a current timestamp to the automation device 14 when the readout process is started. Based on the current timestamp, the automation device 14 can then convert the time information 18 of the previously recorded events into corresponding relative times and assign them to the events. The relative times can then be stored in the event log 20 and transmitted to the readout device 40 together with the event information 16.

[0046] At the in Fig. In the embodiment shown in Figure 1, the readout device 40 and / or the automation device 14 are further configured to calculate a correction factor 48 based on information about a time change of the internal clock 34 of the automation device 14 and to store this correction factor in the event log 20. The relative time of the recorded events is then determined with respect to the readout time, taking the correction factor 48 into account. This ensures that errors in the relative time calculation do not occur due to the time change of the internal clock 34 of the automation device 14, provided that the time information 18 of the recorded events is stored as an absolute timestamp 36 before readout, as explained above.

[0047] If system 10 is implemented without further specific measures, latencies between request and response when reading event log 20 can, for example, create a time lag that can lead to additional inaccuracies. In many applications, this is not a problem, as only an approximate time is important when tracking events. If there is a correlation between the event, such as with a maintenance intervention, an accuracy of a few minutes is usually sufficient.

[0048] If events from several plant components or machines 26 are to be compared with each other, it may be sufficient for several event logs 20 to be comparable in terms of time. In this case, it is advantageous if the event logs 20 are synchronized with each other. For this purpose, it has proven advantageous to synchronize the internal clock 34 of the automation device 14 with the clock 42 of the readout device 40, in particular by means of an NTP protocol 46.

[0049] Alternatively or additionally, the reading device 40 can also be configured to generate a temporary clock 50 in the automation device 14 for the purpose of compiling the event log 20 and / or determining relative time. The reading device 40 can itself function as an NTP server in this context.

[0050] Alternatively or additionally, the automation device 14 can also function as an NTP server and generate a temporary clock 52 on the readout device 40, valid exclusively for the respective event log 20, in particular by means of an NTP protocol 46. The readout device 40 then calculates the deviation from its own clock 42 or the current time and can include this in the readout event log 20. In this way, the relative times of the respective events can also be determined simply and reliably.

[0051] In principle, it is also possible that an NTP server 44, particularly a public one, is available via a network and / or internet connection while the reading device 40 is accessing the automation device 14. This allows the system 10 to be synchronized with Coordinated Universal Time (UTC).

[0052] In the exemplary embodiment, the readout device 40 is configured to determine, based on relative times and a standardized time system, in particular Coordinated Universal Time (UTC), the times at which the recorded events occurred. In other words, the event log 20 can be adjusted to Coordinated Universal Time during logging or log request. For this purpose, the time of the readout device 40 and its time zone, as well as information about whether it is currently summer or winter time, are preferably used. From this information, the event log 20 is converted back to Coordinated Universal Time.

[0053] Furthermore, this is in Fig.1 The reading device 40 shown is configured to determine a first time referenced to the standard time system at the location of the automation device 14 and to determine a second time referenced to the standard time system at the location of the reading device 40 when the automation device 14 and the reading device 40 are located in different time zones of the standard time system.

[0054] This can be particularly advantageous in the case of remote maintenance, as it allows both the local time at the service location and the local time of the maintenance personnel to be determined and displayed, which in turn facilitates the chronological classification of previously recorded events for all involved. For this purpose, time information referenced to Coordinated Universal Time (UTC) can be output.

[0055] In the described embodiment, the readout device 40 is further configured to determine, based on the readout time and at least one further communication time at which it communicates with the automation device 14, a deviation of the internal clock 34 of the automation device 14 from the current time and to correct the speed of the internal clock 34 based on the detected deviation.

[0056] In principle, the speed of the internal clock 34 of the automation device 14 can also be corrected if a deviation of the internal clock 34 is detected compared to external clocks. However, this is only recommended if the respective communication times can be determined accurately, which can be achieved, for example, by using the same NTP server for communication at the different times. Preferably, a speed correction is only performed if a determined time discrepancy between the communication times exceeds the error resulting from the transmissions, for example, due to latency. A key condition for this is that the two communication times are sufficiently far apart in time.

[0057] In addition, it may be provided that the automation device 14 issues a message if the detected deviation exceeds a predetermined limit value, i.e., if the required time correction lies outside an expected maximum.

[0058] The creation of the event log 20 is possible in several ways. For example, a log file (e.g., *.txt, *.csv, *.pdf) can be made available for download on the automation device 14. Alternatively, a spreadsheet file can be provided containing, for example, the query time (especially in UTC format), the event information 16, the difference from the query time, as well as formulas for calculating the UTC time and formulas for determining the local time.

[0059] Another option is to provide the information in a web application running in a web browser, where the conversions (UTC, local time, etc.) take place. Similarly, applications in Docker containers on edge gateways or in the cloud can operate in the same way. Alternatively, applications on querying computers, smart devices, or HMIs (Human Machine Interfaces) are suitable.

Claims

[1] System for determining the time of events occurring in an industrial plant (12), comprising an automation device (14) of the industrial plant (12) which has industrial plant functionality and is configured to detect an event relating to the industrial plant (12) and to store event information (16) and time information (18) associated with the event information (16) in an event log (20); and a readout device (40) which has a current time and is configured to read the event log (20) of the automation device (14), wherein the readout device (40) and / or the automation device (14) is further configured to record a readout time and, based on the readout time and the time information (18) from the event log (20), to determine a relative time of the event in relation to the readout time and to assign it to the event information (16). [2] System according to claim 1, wherein the automation device (14) is configured to operate separately from a network (38), in particular separately from a network (38) with access to an NTP server, in particular to capture events and store them in the event log (20). [3] System according to claim 1 or 2, wherein the automation device (14) is configured to determine the time information (18) with respect to a reference time and to store it in the event log (20), in particular wherein the reference time is the time at which the automation device (14) was last started or reset. [4] System according to one of the preceding claims, wherein the automation device (14) has an internal clock (34) configured to provide an absolute timestamp (36) for each detected event, which is stored as time information (18) for the respective event in the event log (20). [5] System according to claim 4, wherein the readout device (40) and / or the automation device (14) is configured to calculate a correction factor (48) based on information about a time change of the internal clock (34) of the automation device (14) and to store it in the event log (20) and / or to determine the relative time of the event with respect to the readout time taking into account the correction factor (48). [6] System according to claim 4 or 5, wherein the readout device (40) is configured to determine, based on the readout time and at least one further communication time at which it communicates with the automation device (14), a deviation of the internal clock (34) of the automation device (14) from the current time and to correct the relative time and / or the speed of the internal clock (34) based on the detected deviation and / or to issue a message if the deviation exceeds a predetermined limit. [7] System according to any one of claims 4 to 6, wherein the readout device (40) comprises a clock (42) and is configured to synchronize the internal clock (34) of the automation device (14) with its clock (42), in particular by means of an NTP protocol (46). [8] System according to one of the preceding claims, wherein the readout device (40) is configured to generate a temporary clock (50) in the automation device (14) for the purpose of compiling the event log (20) and / or determining the relative time. [9] System according to one of the preceding claims, wherein the automation device (14) is configured to generate a temporary clock (52) in the readout device (40), in particular by means of an NTP protocol (46), and wherein the readout device (40) is configured to determine a deviation of a time of the temporary clock (52) from the current time. [10] System according to one of the preceding claims, wherein the readout device (40) is configured to determine, based on the relative time, a time referenced to a standardized time system, in particular Coordinated Universal Time, at which the event took place. [11] System according to claim 10, wherein the readout device (40) is configured to determine a first time referenced to the standard time system at the location of the automation device (14) and to determine a second time referenced to the standard time system at the location of the readout device (40) when the automation device (14) and the readout device (40) are located in different time zones of the standard time system.

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