DE10161401B4 - Field device for determining and / or monitoring a process variable - Google Patents

Abstract

Field device (1) for determining and / or monitoring a process variable with a measured value transducer (3), field device electronics (2) which comprise an evaluation / control unit (5) and at least one removable storage unit (6.1), with an interface (7 ) a data exchange is carried out between the evaluation / control unit (5) and the removable storage unit (6.1) (6.1) is part of a removable storage module (6) which is assigned to a specific storage module type by means of an individual identifier (6.2), the evaluations - / control unit (5) differentiates and / or recognizes different types of removable memory modules (6) depending on the individual identifier (6.2).

Description

The invention relates to a field device for determining and / or monitoring a process variable according to the preamble of claim 1.

In addition to the primary function, namely the generation of measured values from the measuring signals generated by a measuring transducer, such a field device has numerous other functionalities which support an efficient and reliable guiding of the process to be observed. These include such additional functions as the self-monitoring of the field device, the storage of measured values, the generation of control signals for actuators, the commissioning of the field device and its connection to a data transmission system, etc ..

These and other additional functions of the field devices are usually realized by means of a microprocessor and corresponding run on the microprocessor programs. The associated program codes are usually programmed into a memory prior to the commissioning of the field device, for example in a PROM or in an EEPROM.

The processes observed by means of the field devices are subject to constant modification both with regard to the structural design of the plants and with regard to the chronological sequence of individual process steps. In a corresponding way, the field devices must be adapted to the changing process conditions and further developed. This extends to both the transducers, but above all to the implemented in the field device functions such. As the control of the transducer, the evaluation of the measurement signals or the presentation of the measurement results as well as the communication with a control center via a data transmission system.

For such changes in the implemented functions, appropriate reconfigurations of the stored programs are required in programmable field devices. These reconfigurations are usually carried out on site and may include, for example, the change of individual field device parameters and / or the loading of extensive evaluation programs.

One way to implement the reconfigurations is to replace the built-in memory containing the software to be modified with other memory containing the modified software. This can be done for example by repositioning individual memory elements or by replacing the corresponding memory boards.

A generic field device is in the EP 1 108 984 A1 described. The field device described for determining and / or monitoring a process variable comprises a transducer, a field device electronics, which comprises an evaluation / control unit and at least one removable storage unit, wherein via an interface between the evaluation / control unit and the removable storage unit, a data exchange is performed.

In the published patent application DE 100 49 743 A1 a modular measuring system is described, which in addition to a measuring point with sensors also includes at least one so-called transmission interface for connecting the sensors with an input / output unit, wherein different transmission interfaces have different identifiers for different input / output unit. A special identifier in a memory element of a special transmission interface enables the connection of a special input / output unit to the sensor. The variety of transmission interfaces required for all possible combinations of input / output unit with the measuring point is not desirable in practice.

The invention has the object of developing the generic field device so that a user can easily and quickly adapt the functionality of the field device to new conditions and / or expand.

This object is achieved by the features of claim 1. The subclaims relate to advantageous embodiments and further developments of the invention.

The main idea of the invention is to carry out the removable memory unit as part of a memory module, the memory module being assigned to a specific memory unit of the memory module by means of an individual identifier, and the evaluation / control unit distinguishing different types of removable memory modules depending on the individual identifier and / or recognizes.

On the one hand recognizes the evaluation / control unit by the individual identifier in an advantageous manner automatically for which functions the inserted memory module can be used.

On the other hand, the memory module comprises a plurality of memory units in order to be able to carry out different adaptations and / or extensions simultaneously and to enable a modular expansion of the functional field of the field device.

In a further advantageous embodiment of the invention, the evaluation / control unit executes certain predetermined functions depending on the detected type of memory module and / or sets certain predetermined parameters. As a result, the necessary measures for initializing the memory module and incorporating it into the functionality of the field device are carried out without user intervention. In this way, the functionality of the field device is simply extended and changed and thus optimally adapted to the requirements of the measurement task and to the wishes of the user. Thus, for example, the necessary parameter data can be easily stored in the field device and due to the individual identifier knows the evaluation / control unit which parameters must be replaced and / or how to use the corresponding memory content for the operation of the field device and / or whether certain in the field device existing or determined data must be stored in the memory module.

The individual identifier of the memory module is realized by electronic components and / or by mechanical components and / or by a program code.

In one embodiment, the individual identifier of the memory module is implemented by an ohmic characteristic resistor having a resistance value dependent on the type of the memory module.

In another embodiment, the individual identifier of the memory module is realized by a plug, which can be plugged in only in a certain position depending on the type of memory module.

In a further embodiment, the individual identifier of the memory module is realized by a codeword permanently stored in the memory module, which depends on the type of the memory module.

The allocation of a memory module to a specific type of memory modules depends on the memory contents of the memory unit and / or on the use of the memory module.

For example, memory modules having stored executable programmed functions are associated with a first type of memory module. Memory modules for memory expansion of the field device are associated with a second type of memory modules. Memory modules for parameterizing the field device are assigned to a third type of memory module. Memory modules which are designed as data loggers are assigned to a fourth type of memory module. It goes without saying that the stored content of a memory module can also comprise combinations of the above-mentioned memory contents, in particular if the memory module comprises a plurality of different memory units. For example, executable programmed functions and free memory locations for memory expansion may be present in a memory module. Such a memory module would then be assigned via its individual identifier a fifth type of memory modules, etc ..

In a particularly advantageous embodiment of the invention, the memory module in addition to the memory unit controls and / or display elements.

This makes it possible, regardless of the field device in which the memory unit is installed to perform necessary operating steps or to visualize specific data on site, especially if the affected field device does not have its own display and / or controls.

Thus, in a particularly advantageous embodiment of the invention, the operating instructions that are needed in the language of the user stored in the memory module (for example, in Japanese, English, French or German, etc.). In addition, the corresponding conversion tables for country-specific units of measure can be stored in the memory module. This converts and displays the measurements in the unit of measure expected by the user. These measures make it easy to adapt the user guidance to the respective destination country.

In a werteren embodiment of the invention, the removable memory module is designed as a memory card and the interface in the field device electronics includes a corresponding card reading unit. As a memory card here all storage media are to be understood, which can be accessed directly via electrical contacts or contactless, such as optical or electromagnetic signals.

In another embodiment, the interface is designed as a transmitter / receiver unit for a wireless data exchange. The wireless data exchange between the field device electronics and the memory module is carried out, for example, by infrared signals or by radio signals, or by an inductive data transmission (transponder technology). In contrast to the variant with memory card described above, there is no direct physical access to the storage medium.

In a werteren advantageous embodiment of the invention, the interface and the memory module with intrinsically safe circuits executed, whereby the memory module can also be operated and / or plugged in potentially explosive areas.

By the described embodiments and further developments of the invention, parametrization data, lists of error conditions or measured values, as well as the actual program code can be stored in the field device electronics and also parameterization data can be transferred to other devices, for example in tank farms, which enables the commissioning of many similar level sensors or facilitates the documentation of measured values, error codes or parameter data. The special advantage of this is that the user does not have to install a multiplicity of different operating programs on his computer and, due to the rare use, does not have to familiarize himself again and again with the operation. In addition, it is now possible by simply plugging in the memory module to take over the parameterization data and possibly also the operating program in the installed replacement electronics in case of failure of the field device electronics. Thus, even extensive parameterization data with many different parameters and lists of values (reference curves, linearization tables) that can contain more than a thousand points can be easily transmitted, whereby the field device electronics automatically knows how to handle the data by means of the individual identifier. A small and compact design of the memory module allows for quick installation even in difficult installation locations with extreme environmental conditions, such as a level gauge on a high laddered silo or field devices in areas of high dirt, high humidity, high vibration or high temperatures ,

By means of the memory module according to the invention, therefore, any data can be transmitted directly from the internal memory to the memory module without going through the detour via a computer with an operating program. This is interesting in the current state of the art because, on the one hand, the measuring devices usually already contain an alphanumeric display for operating control and are therefore easy to operate even without an external operating program and because, on the other hand, purely electronic storage media without any mechanics are now small and cheap, so that they can also remain in the device.

In addition, it is possible that the internal memory of the field device electronics is designed as part of the removable memory module.

The invention will be explained in more detail with reference to the following drawing. The sole FIGURE shows a block diagram of a field device according to the invention.

As can be seen from the figure, the field device according to the invention comprises 1 , a field device electronics 2 , a transducer 3 and corresponding signal paths 4 for transmission of the transducer 3 generated measuring signals to the field device electronics 2 or for the transmission of the field device electronics 2 generated control signals to the transducer 3 , As the figure further shows, the field device electronics 2 an evaluation / control unit 5 , a removable memory module 6 which is a storage unit 6.1 , an individual identifier 6.2 , which is executed here as a stored code word X1, multiple controls 6.3 and a display device 6.4 includes, and an interface 7 with appropriate signal paths 7.1 for data exchange between the memory module 6 and the evaluation / control unit 5 , where signal paths are designed as a data bus. In addition, the field device electronics has an interface 4.1 via which the field device electronics 2 the signal exchange with the sensor 3 performs and over another interface 8th for connection of the field device 1 to a data transmission system 9 for communication with a higher-level unit or process control center, not shown.

The memory module 6 communicates via the interface 7 and the signal paths 7.1 with the field device electronics 2 , or with the evaluation / control unit 5 , During communication, data from the evaluation / control unit 5 to the memory module 6 and / or from the memory module 6 to the evaluation / control unit 5 be transmitted. The communication can be done via the memory module 6 arranged controls 6.3 , which are executed, for example, as a push-button, are controlled. Additionally is on the memory module 6 a display element 6.4 arranged to receive feedback on performed actions, the feedback can be done as an optical (LED, LCD display) and / or as an acoustic (beeper) display.

For the design of the interface 7 between field device electronics 2 and memory module 6 Advantageously, an existing standard is used. This facilitates the use of cheaper, because in large numbers manufactured components. At the same time, the memory module 6 for programming comparatively easy with a computer (not shown) are connected.

In addition, the interface 7 as a transmitting / receiving unit for a wireless data exchange between the field device electronics 2 and the memory module 6 be executed. The interface can then be used as an optical (eg infrared interface) or as a radio interface (eg with a Bluetooth protocol) or as an inductive interface (transponder technology). When using the transponder technology, it is possible that the power supply for data transmission via the air interface of the field device electronics 2 is done so that the memory module 6 despite wireless data transmission no own power source needed.

As storage units 6.1 It is preferable to use purely electronic memories such as PROM, EPROM, EEPROM, NOVRAM, Smart Media Card, Compact Flash Card or Multimedia Card because of their robustness, low cost and small size.

By the equipment of the memory module 6 with controls 6.3 and display elements 6.4 can the memory module 6 be used in a particularly advantageous manner as a removable parameter memory. The memory module 6 is for this purpose successively in the field device electronics 2 various field devices 1 plugged in and the stored parameters in the respective field device electronics 2 transferred and stored there in an internal memory (not shown). The memory module 6 can be designed to fit the parameters of many field devices 1 sufficient for then only a memory module 6 is needed. The field device electronics 2 can be designed so that the memory module 6 be housed within the housing and can remain permanently in the device. This will become the memory module 6 in the event of an electronic defect simply plug it into the replacement device and the stored data can be sent to the new field device electronics 2 be transmitted. The housing is designed so that the memory module 6 it has no space, then it can be plugged in with the electronics compartment lid open and removed after the data transmission again.

The memory module 6 can also be used as a data logger. It can in the memory module 6 In addition to the measured value, a list of device states (error codes, power on, power off, operation outside of the specified range, for example too high a temperature, etc.) are stored. The storage unit 6.1 For this purpose, it can be embodied as a circular buffer so that the oldest data is overwritten when the memory is full. To read the data, the memory module can be removed and replaced with another memory module with empty memory. Optionally, the data can also be transmitted via the interface 8th the field device electronics 2 be read out. The data logger function is particularly interesting where permanent monitoring and documentation is desirable or mandatory (eg temperature value in cold stores or water quality in wastewater treatment plants).

In a particularly advantageous manner, the memory module 6 used for menu navigation and to display help texts in different languages. The country-specific memory module 6 is then simply plugged in, and not all possible language variants in the field device 1 be saved yourself. The advantage over a choice of the language variant in the manufacturing plant, for example, that the field device ( 1 ) can be put into operation at a plant manufacturer in Europe with English help texts and the English memory module 6 later at the destination just against a memory module 6 where the help texts are stored in the language used at the destination (eg in Japanese).

The memory module 6 can also be used to program improvements in running series and the already sold field devices 1 benefit by simply adding a memory module 6 with the original program through a new memory module 6 is exchanged with the improved program.

The same applies to additional device functions that are implemented by programs. It contains the new memory module 6 either additional device functions as executable programs or it extends the memory of the field device 1 and thus allows the field device 1 to execute additional algorithms. The advantage of such a modular system is a field device 1 equipped with a low-cost basic version, which can be expanded if necessary by subsequent functional extensions. The modular design thus reduces the manufacturing costs, since fewer variants must be produced. At the same time, the availability is improved, since the low variance far away from the manufacturer can set up local sales warehouses, and the variance there simply by equipping the field device electronics 2 with the appropriate memory module 6 arises, wherein the different functions in one embodiment, each in a memory unit 6.1 are stored. It is of course also possible the different functions in a storage unit 6.1 save.

The distinction of the different memory modules 6 takes place according to the invention by the individual identifier 6.2 the memory modules 6 , For example, by a characteristic resistor or a plug that can be inserted only in a certain position, or by a programmed code word. This detects the field device electronics 2 the type of memory module 6 (Memory extension, function extension, data logger, etc.). In the described embodiment, an action is automatically triggered by the evaluation / control unit after insertion of the memory module depending on the type of memory module. For example, it will be data from the memory module 6 read out and / or data in the memory module 6 transfer.

The memory module 6 and the interface 7 are designed with intrinsically safe circuits and can thus be operated and / or plugged in potentially explosive areas.

LIST OF REFERENCE NUMBERS

1

field device

2

Field device electronics

3

transducer

4

pathway

4.1

interface

5

Evaluation / control unit

6

memory module

6.1

storage unit

6.2

individual identifier

6.3

controls

6.4

display element

7

interface

7.1

pathway

8th

interface

9

Data transfer system

Claims (15)

Field device ( 1 ) for determining and / or monitoring a process variable with a transducer ( 3 ), a field device electronics ( 2 ), which an evaluation / control unit ( 5 ) and at least one removable storage unit ( 6.1 ), whereby via an interface ( 7 ) between the evaluation / control unit ( 5 ) and the removable storage unit ( 6.1 ) a data exchange is performed, characterized in that the memory unit ( 6.1 ) Part of a removable memory module ( 6 ), which by means of an individual identifier ( 6.2 ) is assigned to a specific memory module type, wherein the evaluation / control unit ( 5 ) depending on the individual identifier ( 6.2 ) different types of removable memory modules ( 6 ) differs and / or recognizes. Field device ( 1 ) according to claim 1, characterized in that the memory module ( 6 ) several storage units ( 6.1 ). Field device ( 1 ) according to claim 1 or 2, characterized in that the evaluation / control unit ( 5 ) depending on the detected type of memory module ( 6 ) performs certain predetermined functions and / or sets certain predetermined parameters. Field device ( 1 ) according to one of claims 1 to 3, characterized in that the individual identifier ( 6.2 ) of the memory module ( 6 ) is realized by an electronic component and / or a mechanical component and / or a program code. Field device ( 1 ) according to claim 4, characterized in that the individual identifier ( 6.2 ) of the memory module ( 6 ) is realized by a characteristic resistor. Field device ( 1 ) according to claim 4, characterized in that the individual identifier ( 6.2 ) of the memory module ( 6 ) is realized by a plug. Field device ( 1 ) according to claim 4, characterized in that the individual identifier ( 6.2 ) of the memory module ( 6 ) by a predetermined in the memory module ( 6 ) stored code is realized. Field device ( 1 ) according to one of claims 1 to 7, characterized in that the assignment of the memory module ( 6 ) to a particular type of memory contents of the memory units ( 6.1 ) and / or the use of the memory module ( 6 ) is dependent. Field device ( 1 ) according to claim 8, characterized in that in the memory unit ( 6.1 ) executable software functions and / or help texts and / or parameterization data and / or reference curves and / or linearization tables are stored. Field device ( 1 ) according to claim 8, characterized in that the memory module ( 6 ) for memory expansion and / or menu navigation and / or parameterization of the field device ( 1 ) and / or used as a data logger. Field device ( 1 ) according to one of the preceding claims, characterized in that the memory module ( 6 ) Controls ( 6.3 ) and / or display elements ( 6.4 ). Field device ( 1 ) according to one of the preceding claims, characterized in that the interface ( 7 ) comprises a card reading unit and that the removable memory module ( 6 ) is executed as a memory card. Field device ( 1 ) according to one of the preceding claims, characterized in that the interface ( 7 ) as a transmitting / receiving unit for a wireless data exchange between the field device ( 1 ) and the memory module ( 6 ) is executed. Field device ( 1 ) according to claim 13, characterized in that the interface ( 7 ) when Infrared interface or as a radio interface or as an inductive interface is executed. Field device ( 1 ) according to one of the preceding claims, characterized in that the interface ( 7 ) and / or the memory module ( 6 ) is designed with intrinsically safe circuits.

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