JP5585322B2 - Field equipment - Google Patents

Description

  The present invention relates to a field device, and in particular, relates to use right management of a diagnostic function in a field device connected to a host system via a field bus.

  Various plants including petrochemical plants are required to have as high an operating rate as possible. Therefore, for example, in a pipeline in a petrochemical plant, when measuring the flow rate of various liquids, gases, vapors, etc., it is relatively easy to prevent troubles in the stable control of the plant due to the failure of the flow meter. As a highly stable flow meter, an orifice type flow meter in which an orifice, a differential pressure transmitter, and a pressure guiding pipe for transmitting pressure from the orifice to the transmitter is used.

  By the way, although the reliability of the orifice and the transmitter that make up the orifice type flow meter is extremely high, the fluid may solidify inside the impulse line due to environmental changes or foreign matter may accumulate, resulting in clogging. There is a report that 30% or more of the failure of the meter is clogged of the pressure guiding tube (Non-patent Document 1).

  Therefore, in order to avoid the occurrence of a failure in the orifice type flow meter, as described in Non-Patent Document 1, a differential pressure transmitter is used by using a diagnostic software tool incorporated in a plant facility integrated management system. The measurement signal is sampled, the clogging state of the pressure guiding tube is diagnosed on-line, and an alarm is issued if necessary. The plant facility integrated management system is configured to remotely monitor all plant facilities including field devices via a field network.

  The diagnostic software tool described in Non-Patent Document 1 periodically diagnoses clogging of a pressure guiding tube according to a prepared diagnostic navigator while sequentially storing measurement signals of field devices in a database, and the diagnosis result is obtained. It is displayed on the display screen of the diagnosis navigator, and it is not assumed that the field device itself performs self-diagnosis.

  Therefore, it is necessary to secure a transmission time for transmitting the raw measurement signal of the field device to the host system via the field bus. When the number of field devices connected to the field bus increases, each field device is diagnosed. The period is relatively long.

  On the other hand, with recent advances in fieldbus and information processing technology and dramatic improvement in network transmission speed, as described in Non-Patent Document 2, field devices themselves are highly self-contained such as pressure guiding tubes. A device capable of performing a diagnosis and transmitting the diagnosis result to a host system via a field bus has been put into practical use.

  FIG. 5 is a block diagram illustrating an example of a plant monitoring system including a field device with a diagnostic function described in Non-Patent Document 2. In FIG. 5, a plurality of field devices 2 having a self-diagnosis function are connected to a host system 1 such as a distributed control system (DCS) via a field bus FB.

  These field devices 2 include a process measurement value calculation unit 2a, a diagnostic variable calculation unit 2b, a diagnostic analysis unit 2c, a diagnostic program storage unit 2d, a diagnostic result storage unit 2e, a bus communication interface 2f, and the like.

  The process measurement value calculation unit 2a calculates process measurement values such as flow rate, temperature, pressure, PH value, and concentration based on an output signal of a sensor (not shown).

  The diagnostic variable computation unit 2b performs computations for digitizing signal fluctuations, drift components, and the like, which were conventionally regarded as disturbances, as diagnostic variables.

  The diagnostic analysis unit 2c defines an appropriate diagnostic evaluation function by combining a plurality of diagnostic variables in order to digitize the diagnosis. Diagnostic variables are treated as random variables because they have a greater proportion of irregular disturbances than process variables. The diagnostic evaluation function includes statistical processing calculations such as mean values and standard deviations for random variables, differential / ratio calculations to eliminate disturbances, correction calculations based on other measurement information, calculations to compare with reference conditions, etc. Use in combination. In addition, an FFT that converts a time-domain variable into a frequency-domain variable, a wavelet transform that integrates multiplications of unsteady process variables and appropriately assumed basis functions, and the like can also be used as a diagnostic evaluation function.

  The latest diagnostic program is downloaded and stored in the diagnostic program storage unit 2d through digital communication of the fieldbus FB. As a result, the latest diagnostic algorithm can be implemented without replacing the printed circuit board inside the field device.

  The diagnostic result storage unit 2e stores the diagnostic analysis result in the diagnostic analysis unit 2c.

  The bus communication interface 2f exchanges various signals and data such as measurement information and diagnostic programs with the host system 1 via the field bus FB.

  With the configuration as shown in FIG. 5, physical chemical amounts in the plant such as flow rate, temperature, pressure, PH value, and concentration are measured and the measurement information is provided to the host system 1, and the self-diagnosis of the field device 2 and the surroundings are provided. Information for supporting the maintainability and safety of plant operations such as equipment diagnosis, control loop equipment diagnosis, and device performance diagnosis is also not used for raw data communication as in the past, so the fieldbus FB can be used for a long time. The host system 1 can be efficiently provided without being occupied.

  Further, since the diagnosis is performed by the field device itself, the diagnosis cycle can be shortened, and the diagnosis can be speeded up and the accuracy can be increased.

  FIG. 6 is a purchase example diagram of a conventional field device, (A) shows a case where a transmission device with an additional function such as a diagnostic function is purchased, and (B) purchases a transmission device without an additional function. Shows the case. By purchasing transmission equipment with additional functions, additional functions can be used as needed. On the other hand, if a transmission device without an additional function is purchased, even if the additional function becomes necessary after purchase, the function cannot be used unless it is externally attached.

Nobuo Miyachi and two others, “Diagnosis of pressure guiding tube clogging of differential pressure transmitter”, Yokogawa Technical Report, Yokogawa Electric Corporation, January 20, 2004, Vol. 48 No. 1 (2004) p. 33-36 Yoshiyuki Yuki, 1 other person, “Advanced diagnostic technology in field devices for realizing Asset Execellence”, Yokogawa Technical Report, Yokogawa Electric Corporation, May 20, 2007, Vol. 51 No. 2 (2007) p. 19-22

  However, the diagnosis function of the field device such as the presence or absence of occurrence in the pressure guiding tube as shown in FIG. 5 is not necessarily required by all users of the field device. It is sufficient that standard functions can be used, and it is desirable that the price does not include diagnostic functions.

  In addition, even for users who need the diagnostic function, the user himself / herself checks the state of detection of the pressure guiding tube for the fluid to be measured by the user, and based on the result, the diagnostic function is used for plant monitoring. It may be possible to determine whether or not to employ.

  Users who have adopted the diagnostic function for plant monitoring have needed the diagnostic function from the beginning, so the satisfaction with cost effectiveness has been satisfied, but the user who has not been able to adopt the diagnostic function for plant monitoring diagnoses Even though the function is required, the built-in diagnostic function cannot be used, so that the cost-effectiveness remains unsatisfactory.

  Further, the diagnostic function for the field device is not necessary at the time of the initial operation of the plant, but the diagnostic function for the field device may be necessary due to a subsequent product change in the plant.

  On the other hand, as a field device manufacturer, diversification of specifications due to the combination of various additional functions including the presence or absence of diagnostic functions increases the overall management man-hours from release to maintenance service after delivery. It becomes a factor and is not preferable.

  The present invention solves these problems, and an object of the present invention is to provide a field device having an appropriate cost-effectiveness with a high degree of freedom in changing specifications that can use additional functions by purchasing a license key as necessary. Is to provide.

In order to achieve such a problem, the invention according to claim 1 of the present invention is:
In field devices with standard functions and self-diagnosis functions as additional functions,
Additional function management means for managing the self-diagnosis function as a trial period that can be used freely for a predetermined period set in advance, and managing the self-diagnosis function by inputting a predetermined license key after the trial period has elapsed,
Is provided.

The invention according to claim 2
The field device according to claim 1,
The self-diagnosis function is managed by the additional function management means with a trial period and a license key set in common for a plurality of additional functions.

The invention described in claim 3
The field device according to claim 1,
The self-diagnosis function is managed by the additional function management means using a trial period and a license key individually set for a plurality of additional functions.

The invention according to claim 4
The field device according to any one of claims 1 to 3,
The self-diagnosis function is at least one of a self-diagnosis function of a pressure guiding tube in a differential pressure transmitter, a steam trace diagnosis function in a differential pressure transmitter, and a function of diagnosing dirt adhesion to an electrode in an electromagnetic flow meter. To do.

  Thus, the user can freely use the additional function of the field device during the trial period, and can use it by purchasing and inputting the license key after the trial period has elapsed.

It is a block diagram which shows one Example of this invention. It is an equivalent circuit diagram of an electromagnetic flow meter. It is a flowchart which shows the flow of a series of operation | movement which purchases and uses the field apparatus based on this invention. It is a flowchart which shows the flow of a series of operation | movement which purchases and uses the field apparatus based on this invention. It is a block diagram which shows an example of the plant monitoring system containing the conventional field device with a diagnostic function. It is a purchase example figure of the conventional field device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, showing an example in which a plurality of additional functions are implemented. In FIG. 1, an additional function use license key 4 purchased by a user from an additional function use license key seller 3 is input to the field device 2 as necessary. As the license key 4, for example, a character string / numerical value unique to each transmission device is used.

  The field device 2 measures the physical chemical amount in the plant such as flow rate, temperature, pressure, PH value, concentration, etc. and provides the measurement information to the host system 1 in the same manner as in the past, and a pressure guiding tube, The additional function unit 22 including the self-diagnosis function and the additional function management unit 23 that individually manages the use of the additional function of the additional function unit 22.

  The additional function unit 22 includes a self-diagnosis function of the pressure guiding tube in the differential pressure transmitter of the orifice type flow meter, a steam trace diagnostic function in the differential pressure transmitter as described in Non-Patent Document 2, The function of diagnosing the adhesion of dirt to the electrodes in the flow meter is mounted in advance according to the configuration of each transmitter.

  The steam trace diagnostic function is a function that diagnoses the soundness of steam when measuring the differential pressure by steam tracing so that the liquid is not solidified by keeping the pressure guiding pipe and flange in the differential pressure transmitter of the orifice type flow meter. It is.

That is, the following equation is established to estimate the flange temperature (FLANG-TEMP) based on the capsule temperature (CAP-TEMP) and the amplifier temperature (AMP-TEMP) of the differential pressure transmitter.
(FLANG-TEMP) = (1 + K) * (CAP-TEMP)
-K * (AMP-TEMP)
By optimizing the value of K in this equation, the flange temperature (FLANG-TEMP) can be calculated, and the soundness of the steam that keeps the pressure guiding tube warm can be diagnosed.

  The function of diagnosing dirt adhesion to electrodes in the electromagnetic flow meter will be described with reference to the equivalent circuit diagram of the electromagnetic flow meter shown in FIG. In FIG. 2, a very small rectangular current is supplied from the current source 52 connected to the electrode 51 to the earth ring 53, and the resistance value is measured based on the principle of Ohm's law. The degree of contamination is diagnosed as the resistance value 54. The frequency of the rectangular wave current output from the current source 52 is set so as not to affect the flow rate signal calculation, and the flow rate signal during the time for performing the signal processing for electrode dirt adhesion diagnosis is masked so that the signal for dirt adhesion diagnosis is obtained. The stain adhesion diagnosis is performed in a stable state.

  The additional function management unit 23 includes a trial period counter 23a for each additional function and a key management unit 23b for each additional function.

  The trial period counter 23a for each additional function is configured to count a predetermined trial period preset for each additional function, and is activated when the field device 2 starts to be used. The user can freely use each additional function while measuring the actual measurement object until the count value of the trial period counter 23a for each additional function reaches a predetermined set value, and based on the diagnosis result. Thus, it can be determined whether or not the additional function is adopted for plant monitoring.

  When a predetermined trial period individually set in the trial period counter 23a for each additional function elapses, each additional function cannot be used.

  When the user wants to use the additional function even after the trial period has elapsed, the user purchases the corresponding additional function use license key 4 from the additional function use license key seller 3 and adds the license key 4 to the field device 2. This is input to the function-specific use key management unit 23b. When the predetermined license key 4 is input to the additional function use key management unit 23b of the field device 2, the corresponding additional function can be used again.

  In the embodiment of FIG. 1, the example in which the use of a plurality of additional functions installed in the field device is individually managed for each additional function by the additional function management unit 23 has been described. You may make it manage with the trial period and license key which were set to.

  FIG. 3 is a flowchart showing a flow of a series of operations for purchasing and using field devices according to the present invention, and shows an example in which a single or a plurality of additional functions are commonly managed. When the user purchases a transmitter, which is a field device having an additional function (step S1), and is installed on the site such as a pipeline and starts to be used, the trial period counter 23a is activated (step S2).

  The additional function of the transmitter can be evaluated by freely using the fixed period counted by the trial period counter 23a as the trial period (step S3). For the trial period counter 23a, it is periodically checked whether or not the count value has reached a preset value set as a trial period (step S4).

  When the count value of the trial period counter 23a reaches the set value set in advance as the trial period, it is confirmed whether or not a license key for the additional function has been purchased and input to the key management unit 23b (step S5). If the additional function license key is not input to the key management unit 23b, the additional function cannot be used (step S6), but if the license key is input to the key management unit 23b, the additional function can be used continuously. (Step S8).

  Even after the additional function cannot be used, it can be used again by purchasing a license key for the additional function and inputting it to the key management unit 23b (step S7).

  As a result, the user confirms the convenience and necessity of these additional functions at the installation site of the transmitter by actually using various additional functions within the trial period set by the trial period counter 23a. Can be evaluated.

  If the user determines that any of these additional functions is worthy of continuous use, the use of the additional functions can be resumed by purchasing a license key for the additional functions and inputting it to the key management unit 23b.

  In addition, manufacturers can improve productivity and reduce costs by unifying product specifications with additional functions.

  FIG. 4 is also a flowchart showing a flow of a series of operations for purchasing and using a field device based on the present invention, and shows two examples of additional functions. In the example of FIG. 4, for the additional function 1 and the additional function 2, the setting value of the trial period counter is set individually and the license key is sold.

  That is, processing related to management of additional function 1 from step S3 to step S8 and processing related to management of additional function 2 from step S9 to step S14 are performed individually in parallel.

  Since the trial period of the additional function 1 and the additional function 2 can be individually set, the user can sufficiently determine the difference and necessity of the contents of the additional function 1 and the additional function 2.

  In addition, the manufacturer can set the selling price corresponding to each value for the additional functions having different function values by individually setting the license keys of the additional function 1 and the additional function 2.

  When purchasing a field device with standard functions and additional functions, the user can confirm the use of the additional functions that have been implemented for a specified trial period by paying the price set based on the standard functions. Since the additional function can be used by purchasing and inputting the license key based on the use result of the additional function within the period, an improved cost-effectiveness can be obtained compared to the conventional case.

  As described above, according to the present invention, it is possible to realize a field device having a high degree of freedom in changing specifications that can use additional functions by purchasing a license key as necessary, and having an appropriate cost-effectiveness.

2 Field device 21 Standard function section 22 Additional function section 23 Additional function management section 23a Additional function trial period counter 23b Additional function use key management section 3 Additional function use license key Vendor 4 Additional function use license key

Claims (4)

In field devices with standard functions and self-diagnosis functions as additional functions,
Additional function management means for managing the self-diagnosis function as a trial period that can be used freely for a predetermined period set in advance, and managing the self-diagnosis function by inputting a predetermined license key after the trial period has elapsed,
Field equipment characterized by providing 2. The field device according to claim 1 , wherein the self-diagnosis function is managed by the additional function management unit using a trial period and a license key that are set in common for a plurality of additional functions. 2. The field device according to claim 1 , wherein the self-diagnosis function is managed by the additional function management means using a trial period and a license key individually set for a plurality of additional functions. The self-diagnosis function is at least one of a self-diagnosis function of a pressure guiding tube in a differential pressure transmitter, a steam trace diagnosis function in a differential pressure transmitter, and a function of diagnosing dirt adhesion to an electrode in an electromagnetic flow meter. The field device according to any one of claims 1 to 3.

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