FIELD EQUIPMENT, METHOD FOR OPERATING FIELD EQUIPMENT AND CLOUD SERVICE

Description

[0001] The invention relates to a field device. Furthermore, the invention relates to a method for operating a field device. Finally, the invention also relates to a cloud service.

[0002] In modern process automation, it is common to monitor processes or media using field devices in the form of measuring instruments (sensors) or to influence them using actuators.

[0003] For process management, the field devices are generally connected to a control room, which is part of a process control system. For this purpose, so-called fieldbuses with corresponding protocols are often used (e.g., EtherNet / IP, PROFINET, Modbus TCP, Foundation Fieldbus (FF), Profibus DP or PA, Modbus RTU).

[0004] This allows data to be transferred from the field devices to the control center, or the field devices to receive data, e.g. parameter values ​​or software components, etc., from the control center.

[0005] Document US2007161367A1 discloses such a field device and a method for operating a field device.

[0006] One disadvantage is that data and access are generally limited to the process control system, which houses the control room and field devices. Therefore, data access is usually not possible outside the process plant. Even with widely distributed field devices, direct data access at the field device itself is sometimes the only option. Consider, for example, a decentralized water supply network.

[0007] The invention is therefore based on the objective of simplifying data communication with field devices.

[0008] Cloud computing refers to the on-demand provision of data processing resources of any kind, enabling data to be processed and stored on different devices. However, "cloud" can also refer to a server accessible via a network, including at least the field device, or via the internet (e.g., file server, email server, database server, etc.). This allows, for example, flexible increases in computing capacity when more complex calculations are required. Furthermore, it makes stored data available via different routes and access points.

[0009] According to the invention, a cloud interface is provided through which data can be exchanged between such a cloud and a field device, i.e., through which the field device can output and / or receive data.

[0010] Generally, bidirectional data transfer between the cloud and field devices is possible. This data transfer can occur according to a fixed pattern or, for example, as a result of a query. Furthermore, a simple data transfer can be supplemented by an acknowledgment from the receiving end.

[0011] In one embodiment, the field device itself has the interface, which is therefore a component of the field device.

[0012] In an alternative configuration, the field device has a standard interface that, for example, allows connection to a state-of-the-art fieldbus. The cloud interface is part of a separate communication device, so that the field device communicates with the communication device via the standard interface and with the cloud via the communication device's cloud interface. In this configuration, the field device can therefore also be a standard, state-of-the-art field device that exchanges data with the cloud via a separate communication device.

[0013] In particular, if the field device is autonomous or if, for example, repeated queries are to be avoided, one design provides that the field device transmits data to the cloud and / or receives data from the cloud according to a predefined time schedule.

[0014] The timing scheme refers, for example, to a time interval between the transmission and / or reception of the data. In particular, when used in conjunction with a real-time clock device, a specific time schedule is alternatively predefined for the field device.

[0015] If the field device is a measuring instrument, it will start a measurement accordingly, so that the measured value or possibly several measured values ​​can be transmitted in data form at the appropriate time.

[0016] In one configuration, a time schedule is stored in the cloud, so that the cloud sends query signals to the field device and / or multiple field devices according to this schedule. Alternatively or additionally, the time schedule is stored in at least one field device, so that the field device transmits data to the cloud automatically and without a query from the cloud.

[0017] Alternatively or additionally, in one configuration, query signals are transmitted to the field device or the cloud outside of a fixed time schedule. This applies, for example, to manually querying measured values, transmitting configuration data, or performing a firmware update.

[0018] In one embodiment, the field device is provided for to temporarily enter an energy-saving state. In this state, for example, components are not supplied with energy or are supplied with reduced energy, or certain functionalities are not executed. This embodiment is particularly advantageous if the field device, for example, only has a battery or accumulator, or generally only a limited self-sufficiency power supply, e.g., from an energy harvester in the form of a solar module.

[0019] According to one teaching, the above problem is solved by a method for operating a field device according to claim 1.

[0020] According to the invention, data access or control of a process plant in which at least one field device is located is simplified by communicating data between the field device and a cloud via a cloud interface.

[0021] To ensure that at least one field device communicates only with the correct cloud, an activation process is included in one design.

[0022] During the activation process, at least one activation code is transmitted from the cloud to the field device. The activation code preferably contains at least one piece of information about the cloud or, preferably, also about the instance that provides the cloud as a service.

[0023] After receiving the activation code, i.e., after the field device has learned through the activation code that a connection should be established between the cloud sending the activation code and the field device, the field device enables verification of the received activation code.

[0024] In one implementation, this means that the field device displays the activation code or information derived from it on a display unit. If the display is successful, a user confirms this, allowing the field device to communicate with the relevant cloud.

[0025] In a further embodiment, a mechanism is described by which the field device is caused to transmit data to the cloud.

[0026] The plan is to transmit a query signal to the field device.

[0027] The query signal can be implemented as an arbitrarily short data packet, since the query signal itself does not transmit any information; rather, the information to the field device consists of receiving such a query signal. It is therefore sufficient if it is unambiguous that it is such a query signal.

[0028] In one configuration, the field device queries the cloud for information following the received query signal. Based on the information returned by the cloud, the field device then transmits data to the cloud. In this configuration, the field device essentially queries which data it should transmit to the cloud.

[0029] Alternatively, the field device transmits data to the cloud after receiving the query signal. In this configuration, the field device therefore reacts automatically to the query signal by transmitting data to the cloud.

[0030] In another alternative configuration, the field device receives data from the cloud after receiving the query signal. In one variant, the field device reacts to the query signal by requesting information from the cloud and subsequently receiving confirmation that data, such as configuration data or a software update, is available for download. In an alternative variant, the query signal itself already includes this information regarding the new data for the field device, allowing the device to receive or retrieve the new data from the cloud immediately after receiving the query signal.

[0031] The transmitted data includes, for example, measured values ​​or data that more precisely describe the field device or its current state.

[0032] In one implementation, the receipt of data is confirmed or acknowledged. For example, one variant stipulates that the cloud confirms the receipt of data to the field device. In a supplementary or alternative variant, the field device confirms the receipt of data to the cloud.

[0033] One embodiment involves confirming the receipt of data by transmitting at least one time for at least one subsequent data transmission. In another embodiment, the receipt of data is confirmed by transmitting at least one new time sequence, where the time sequence consists of at least one time at which a subsequent, i.e., next, data transmission is to take place.

[0034] In one embodiment, it is provided that the cloud confirms the receipt of data to the field device by transmitting a time for at least one subsequent data transmission from the field device to the cloud to the field device, and / or that the field device confirms the receipt of data to the cloud by transmitting a time for at least one subsequent data transmission from the cloud to the field device to the cloud.

[0035] Regarding the timing scheme according to which the field device automatically transmits data to the cloud, one configuration provides that the cloud confirms receipt of data to the field device by sending the field device a time for at least one subsequent data transmission from the field device to the cloud. Data receipt is thus acknowledged by the field device receiving a time for at least one further data transmission to the cloud.

[0036] Alternatively or additionally, one embodiment provides that the field device confirms the receipt of data to the cloud by transmitting a time for at least one subsequent data transmission from the cloud to the field device.

[0037] In a further embodiment, multiple points in time are communicated, for example by announcing the time interval between a predefined number of successive data transmissions.

[0038] According to another theory, the above task is solved by a cloud service, via which data communication with at least one field device is realized.

[0039] According to the invention, data communication is thus realized by providing a corresponding cloud or cloud service through which data communication with at least one field device takes place. A cloud service is therefore offered by corresponding computing units or storage units, which in one embodiment are also part of the computing units, through which at least one field device can be addressed or to which at least one field device can transmit its data.

[0040] The cloud service is provided in one configuration using user-provided components and in an alternative configuration as an external service.

[0041] The above statements regarding the field device or the procedure and the advantages mentioned therein also apply to the cloud service or can be implemented via it.

[0042] In one configuration, at least one field device is part of a process plant that connects to the cloud.

[0043] In detail, there are numerous possibilities for elaborating and further developing the method according to the invention. Reference is made to the claims subordinate to claim 1. .

[0044] The drawing shows Fig. 1 a schematic representation of a process plant, Fig. 2 a schematic representation of a process plant in an alternative configuration, Fig. 3 a diagram illustrating the flow of communication between a field device and a cloud, and Fig. 4 a configuration that adapts to the flow of Fig. 3 subsequent procedural sequence.

[0045] In the Fig. 1 The figure shows a highly schematic representation of a process plant in which several field devices 1 are present. However, this is only one embodiment, as the invention can also be implemented with just one field device 1. These are partly measuring instruments (for level, flow rate, or pH value) and in one case an actuator in the form of a valve.

[0046] The separately arranged field device 1 for determining the fill level is equipped with its own cloud interface 2, which enables communication with a cloud 3.

[0047] In the configuration shown, data transmission takes place wirelessly, e.g., via radio. Alternatively, the cloud interface can be an Ethernet-based interface or an interface to a cellular mobile data service (e.g., GPRS - for General Packet Radio Service - or HSPA for High Speed ​​Packet Access).

[0048] The other field devices 1 have a standard interface 4 for connection via a fieldbus 5 with a communication device 6. The communication device 6 has a cloud interface 2 and therefore, in the sense of a gateway, enables the field devices 1 connected to it via the fieldbus 5 to communicate with the cloud 3.

[0049] Cloud 3 is implemented by a computing device 7, which provides the corresponding cloud service. In the configuration shown, the computing device 7 is an integral part of the process plant itself.

[0050] In an alternative configuration – not shown – the computing device 7 is operated by an external entity that offers cloud services.

[0051] The field devices 1 have real-time clock devices 8 that allow the data to be time-stamped and also enable measurement and / or data transmission to be carried out at previously defined times.

[0052] Synchronization of the data from field devices 1 is carried out in conjunction with the cloud service, for example using a technique such as the Network Time Protocol (NTP) with a reference time.

[0053] In the Fig. 2 The activation process of a field device 1 is shown schematically.

[0054] The field device 1 is attached to the top of a container 9 and is designed as a measuring device for determining the fill level of the medium 10.

[0055] For an initial connection between field device 1 and Cloud 3, Cloud 3 transmits an activation code to field device 1. This is done via a radio connection and the Cloud interface 2.

[0056] On field device 1, the activation code is displayed via a display / input device 11 in the form of a human-machine interface. A user 12 verifies the code and unlocks field device 1 for communication with cloud 3.

[0057] By only allowing connections to a known Cloud 3, it is prevented that, for example, a listening Cloud 13 initiates a contact and that data thereby ends up with the wrong recipient.

[0058] In the Fig. 3 The following is an example of the communication process between a field device, which serves as a sensor, and a cloud.

[0059] In step 100, the field device is attached to a measurement location. In a possible subsequent step, the field device is added to or registered with the cloud, for example, using a unique identifier (e.g., the phone number of the SIM card used, serial number).

[0060] In step 101, the field device receives an activation code from the cloud, which identifies and marks the specific cloud. This is done, for example, in the form of an SMS.

[0061] The activation code is verified by a user or by service personnel in step 102, so that, if successful, the field device communicates with the cloud from step 103 onwards.

[0062] If the activation code does not originate from an authorized cloud, the connection will be refused, with step 104 in particular generating a signal indicating that an unauthorized connection has been attempted.

[0063] In step 105, the field device enters an energy-saving mode, for example by not supplying energy to the components of the field device that are used for measurement.

[0064] In step 106, the field device transitions to measurement mode based on a time schedule stored in the field device and determines a measured value.

[0065] In step 107, this measured value is transmitted as a raw value to the cloud, which then determines the actual value for the process size from the raw value in step 108.

[0066] Furthermore, the measurement data from multiple field devices is also centrally managed and preferably stored in the cloud.

[0067] In step 109, the cloud transmits a confirmation signal to the field device as acknowledgment of the measured value, whereupon the field device returns to energy-saving mode in step 105.

[0068] In the Fig. 4 This is an alternative scenario in which there is a need for a measured value outside the time schedule stored in the field device.

[0069] To obtain a current measurement value, a query signal is transmitted to the field device in step 110 after step 109.

[0070] In the configuration shown, the query signal falls into one of two possible categories, each of which triggers one of two sequences.

[0071] In one case, the query signal causes the field device to automatically generate a measured value in step 111 and transmit it to the cloud.

[0072] Alternatively, in step 112, the field device queries the cloud to determine which measurement data or information is required.

[0073] In step 113, the cloud transmits a corresponding order to the field device, which is then executed by the field device in step 114.

[0074] In the configuration shown, in step 115 the cloud transmits the next time for sending a measurement value to the field device. This means that for the following steps, the time schedule is reduced to a single point in time, specifically for the next measurement.

[0075] Accordingly, in step 116 the field device enters energy-saving mode in order to generate the measured value in step 117 and transmit it to the cloud.

[0076] As confirmation, in step 118, the field device receives from the cloud the next time for transmission and, if applicable, for the generation of the measured value. The times for acquiring the measured value and the data transmission can differ. For example, one implementation provides for the field device to acquire a predefined number of measured values ​​and then transmit them collectively.

Claims

1. Method for operating a field device (1), wherein data is communicated between the field device (1) and a cloud (3) via a cloud interface (2), characterized in that at least one activation code is transmitted from the cloud (3) to the field device (1) during at least one activation process, that after the field device (1) receives the activation code, verification of the received activation code is enabled, and that after successful verification, the field device (1) communicates with the cloud (3).

2. Method according to claim 1, characterized in that a query signal is transmitted to the field device (1), that after receipt of the query signal from the cloud (3), information is queried by the field device (1) and data is transmitted from the field device (1) to the cloud (3) based on the information, or that data is transmitted from the field device (1) to the cloud (3) after receiving the query signal, or that data is received from the cloud (3) by the field device (1) after receiving the query signal.

3. Method according to claim 1 or 2, characterized in that the cloud (3) confirms the receipt of data to the field device (1) and / or that the field device (1) confirms the receipt of data to the cloud (3).

4. Method according to claim 3, characterized in that receipt of data is confirmed by transmitting at least one point in time for at least one subsequent data transmission.