JP5531786B2 - External indicating instrument - Google Patents

Description

  The present invention relates to an external indicating instrument that collects and displays parameter information included in a plurality of field devices compliant with Foundation Fieldbus (hereinafter referred to as FF) standards connected to a fieldbus via the fieldbus. .

  FIG. 3 is a functional block diagram showing a configuration example of a control system in which a conventional external indicator is mounted. A plurality of field devices 21, 22, and 23 that conform to the FF standard are installed in the process fluid pipe 10 through which the fluid F to be measured flows.

  Here, the field device 21 (PT100) is a pressure measuring device capable of outputting a plurality of process values such as differential pressure and static pressure, such as a differential pressure transmitter. The field device 22 (FT100) is a flow rate measuring device such as an electromagnetic flow meter. The field device 23 (TT100) is a temperature transmitter having a plurality of inputs.

  These field devices include a host device 40 that executes process control and monitoring via a signal transmission line 30 such as a field bus conforming to the FF standard, an external indicator 50 to which the present invention is applied, and parameters for the field devices. It communicates with the setting tool 60 and executes process control.

  The external indicator 50 has a function of receiving the output values of the field devices 21, 22, and 23 via the signal transmission line 30 and displaying the values, and an operator goes around the site and an abnormality occurs in the field devices and processes. Used to check if there is any.

  In the external indicator 50, the field devices 21, 22, and 23 are installed in high places, places that are difficult to access such as high temperature / high humidity, and dangerous atmospheres such as explosive atmospheres. It is used when it is difficult for the operator to check the indicator built in the machine during the patrol.

  In addition, the external indicator 50 is installed in a place where workers can easily access it, and it is possible to view the information of multiple field devices without the need for special tools, thereby reducing worker work and ensuring safety. It contributes.

  The parameter setting tool 60 is a field device setting tool that runs on a PC such as a handheld terminal or Field / Mate DTM, for example, and sets the tags of the field devices 21, 22, and 23, displays process data, An alarm can be displayed based on the diagnosis result.

  The parameter setting tool 60 incorporates a DD (Device Description) conforming to the FF standard. DD is a mechanism for interpreting and displaying field device functions and parameter information, and includes several thousand lines to several tens of thousands, including parameter display assistance, display labels, number of decimal places to be displayed, and help. A driver composed of lines.

  In order for the parameter setting tool 60 to access the field devices 21, 22, and 23, a total of three DDs of the field devices 21, 22, and 23 are required. The DD is prepared for each device and differs depending on the manufacturer and model.

  Generally, dozens of DDs are installed in one device setting tool, and are distributed and installed as an executable file such as a binary type. The parameter setting tool 60 can set tags of the field devices 21, 22, and 23, and obtain process data and alarm information based on information described in the DD by client / server type asynchronous communication.

  The parameter setting tool 60 having a large-capacity memory resource obtains information by accessing an arbitrary parameter at an arbitrary timing by client / server asynchronous communication with the field devices 21, 22, and 23 by the mounted DD. Can do.

  However, since the external indicator 50 does not have a large-capacity memory resource capable of mounting a tool such as DD that enables client / server type asynchronous communication, access to the field devices 21, 22, and 23 can be acquired. Publisher / subscriber type synchronous communication with fixed parameters is used.

  FIG. 4 is a schematic diagram for explaining the publisher / subscriber type synchronous communication. A function block (function block) conforming to the FF standard for displaying the outputs of the field devices 21, 22, and 23 on the external indicator 50 is shown. ). The engineering for combining the functional blocks is executed on a device having an LAS (Link active schedule) function such as the host device 40, for example.

  An analog input block (AI1) 21a built in the field device 21 is a functional block that measures the differential pressure output of the fluid F and outputs it from OUT1. An analog input block (AI2) 22a built in the field device 22 is a functional block that measures the flow rate of the fluid F and outputs it from OUT2. An analog input block (AI3) 23a built in the field device 23 is a functional block that measures the fluid F temperature and outputs it from OUT3.

  An input selector block (ISEL) 50a built in the external indicator 50 outputs the outputs OUT1, OUT2, and OUT3 of the analog input blocks 21a, 22a, and 23a to a separate input IN1, IN2, and IN3, respectively. 1: 1 input by connection, and process values of pressure, flow rate and temperature measured by field devices 21, 22, and 23 are periodically received according to the schedule of LAS by publisher / subscriber type synchronous communication. Can do.

  FIG. 5 is a timing chart showing schedule management of publisher / subscriber type synchronous communication. The uppermost display T indicates the time within a certain period. The time information is distributed from the host device 40 that is the LAS to the field devices 21, 22, and 23 through the signal transmission line 30.

  S1 indicates the execution time of the function block 21a (AI1) built in the field device 21. Starting from 0 ms, after 10 ms, OUT1 is distributed to the input IN1 of the functional block 50a (ISEL) via the VCR.

  S2 indicates the execution time of the function block 22a (AI2) built in the field device 22. Starting from 20 ms, after 10 ms, OUT2 is distributed to the input IN2 of the functional block 50a (ISEL) via the VCR.

  S3 indicates the execution time of the function block 23a (AI3) built in the field device 23. Starting from 40 ms, after 10 ms, OUT3 is distributed to the input IN3 of the functional block 50a (ISEL) via the VCR.

  10 ms starting from 70 ms indicates the execution time of the function block 50a (ISEL). According to the VCR connection shown in FIG. 4 and the LAS management schedule shown in FIG. 5, the external indicator 50 can receive the process data measured by the field devices 21, 22, and 23.

  FIG. 6 is a schematic diagram for explaining a data display mechanism in publisher / subscriber type synchronous communication. In this figure, the tag name and device status from the field device 23 (TT100) acquired by the input IN3 of the function block 50a (ISEL) are interpreted by the LCD setting block 50b and displayed on the LCD 50C.

  FIG. 7 is an example of data display in publisher / subscriber type synchronous communication. The external indicator 50 acquires the tag names and device status information of the field devices 21, 22, and 23 in accordance with the LAS management schedule shown in FIG. 5, and sequentially displays them sequentially on the LCD 50C. The parameters that can be displayed are fixed by engineering and cannot be freely selected by the user.

JP 2007-087099 A

The conventional method of receiving and displaying process data by combining a publisher / subscriber type synchronous communication that reads a plurality of outputs of a plurality of field devices in one place and an input selector block has the following problems.
(1) Process data is used only for display and occupies a control block (for example, an AI block).

  For example, the differential pressure value measured by the field device 21 is passed only to the signal input terminal IN1 of the ISEL block for display by the signal output terminal OUT1 of the AI block 21a. Therefore, the differential pressure value measured by the field device 21 cannot be supplied to a control block such as a PID.

  For this reason, if the differential pressure value is to be used for control, the differential pressure value cannot be used for display on the external indicator 50, and therefore cannot be displayed on the external indicator. Therefore, it is not easy for the operator to check the field equipment, and it is necessary to go directly to the place where the field equipment is installed in a difficult atmosphere such as high places, high temperatures / high places, etc. A decrease in risk and an increased risk of accidents are inevitable.

  Alternatively, if it is desired to display both the control and the external indicator, two field devices, a differential pressure gauge for control and a differential pressure gauge for the external indicator, must be prepared. Cost doubles.

(2) As shown in the scheduling management by LAS in FIG. 5, functional blocks only for display that are not used for control reside in the schedule, and control responsiveness deteriorates.

(3) In the publisher / subscriber type synchronous communication, process data such as a differential pressure value can be sent, but detailed information on various faults and self-diagnosis results cannot be sent.
On the other hand, there is a method of acquiring alarm information based on the process value of the field device and the self-diagnosis result of the device without affecting the control by the client / server type asynchronous communication using DD like the parameter setting tool 60. .

  However, in order to use this method, it is necessary to install / maintain DD of various field devices in the external indicator 50 and to install a program function for interpreting DD, and the external indicator 50 with a small memory resource. It is difficult to use this mechanism as it is.

  An object of the present invention is to realize an external indicator that makes it possible to use client / server type asynchronous communication for communication with a field device even with a small amount of memory resources.

In order to achieve such a subject, the present invention has the following configuration.
(1) In an external indicating instrument that collects and displays parameter information of a plurality of field devices compliant with the Foundation Fieldbus (hereinafter referred to as FF) standard connected to the fieldbus via the fieldbus.
A client / server type asynchronous communication means is provided for accessing and collecting the parameter information selected as a display item among the parameter information included in the field device at an arbitrary timing according to a user designation. External indicator instrument.

(2) The external indicating instrument according to (1), wherein the client / server asynchronous communication means includes a simple dictionary file for accessing selected parameter information of the field device.

(3) The external indicating instrument according to (1) or (2), wherein the simple dictionary file is constructed by engineering a host device connected to the fieldbus.

(4) The simple dictionary file is constructed based on a Device Description (hereinafter referred to as DD) file for accessing all parameter information of field devices based on the FF standard provided in the host device. The external indicating instrument according to (3).

(5) The parameter information collected by the client / server asynchronous communication means is at least one of the device name and status information, alarm information, process value, and message of the field device (1) The external indicating instrument according to any one of (4) to (4).

According to the present invention, the following effects can be expected.
(1) By providing the client / server type asynchronous communication means, the parameter information selected as the display item can be collected and displayed by accessing the field device at an arbitrary timing as specified by the user.

(2) The client / server asynchronous communication means mounted on the external indicator of the present invention does not require a large-capacity DD, and a simple dictionary file for accessing selected parameter information of a field device is a small database. It can be realized by having it. Therefore, the resources provided in the conventional external indicator can be used as they are.

(3) The measurement values of other devices can be obtained without using the publisher / subscriber type synchronous communication and without combining the functional blocks, so it is possible to display without disturbing the control settings and controllability. Blocks not related to control do not need to be put together in a macro cycle, and the AI block is not occupied.

(4) It can also be used in hazardous areas. For example, it is possible to monitor the output of a field device in an explosion / main safety area or a constantly dangerous area in a relatively safe area.

It is a functional block diagram which shows one Example of the control system which mounted the external indicator of this invention. It is a map figure which shows the structural example of a simple dictionary file. It is a functional block diagram which shows the structural example of the control system which mounted the conventional external indicator. It is a schematic diagram explaining publisher / subscriber type synchronous communication. It is a timing chart which shows schedule management of publisher / subscriber type synchronous communication. It is a schematic diagram explaining the mechanism of the data display in publisher / subscriber type synchronous communication. It is an example of a data display in publisher / subscriber type synchronous communication.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of a control system in which the external indicator of the present invention is installed. The same elements as those of the conventional configuration described with reference to FIG.

  The external indicator 100 to which the present invention is applied is equipped with client / server type asynchronous communication means, and includes simple information of field devices 21, 22, and 23, for example, device names and status information, alarm information, process values, and messages. Can be received via the signal transmission line 30 and the value can be displayed.

  The external indicator 100 includes a small database 101, communication processing means 102, user interface 103, and display means 104 as client / server type asynchronous communication means.

  The database 101 includes a simple dictionary file 101a for accessing a selected parameter of the field device 21 (PT100), a simple dictionary file 101b for accessing a selected parameter of the field device 22 (FT100), and a field device 23. A simple dictionary file 101c for accessing the selected parameter of (TT100) is stored.

  The generation of these simple dictionary files is intended to access only the selected display parameters necessary for monitoring, unlike the DD which is intended to access all parameters. By entering the parameter name, INDEX number, etc., the user can easily construct it.

  FIG. 2 is a map diagram illustrating a configuration example of the simple dictionary files 101a, 101b, and 101c. The external indicator 100 only needs to display about several parameters per field device. For example, by reading the device address and the index number of the alarm parameter, the alarm indicator and the like are obtained from the field device on the signal transmission line 30. Can be displayed.

  An area M1 in FIG. 2 is a field device description column on the signal transmission line 30, and DEVICE1, 2, 3 are assigned to, for example, the field device 21 (PT100), the field device 22 (FT100), and the field device 23 (TT100). Corresponding, equipped with client / server type asynchronous communication function.

  The area M2 is a description column for the device-specific Address, the Alert Parameter Index, and the data type of the target data. In the area M3, the actual display of Message1 is like a National Instruments tool (NI-FBUS), and the user can arbitrarily describe and set it. The display can be changed by the user. For example, when the device name is entered in the parameter, the lower parameter can be selected.

  Furthermore, by acquiring the data type of the target alarm parameter and converting and displaying it according to the type, the external indicator displays the alarm information of other devices to the user without having to create and manage the DD for each device. be able to.

  Thus, the simple dictionary file can be constructed by the user, but can also be engineered using the DD file provided in the host device 40 or the parameter setting tool 60 on the signal transmission line 30.

  In FIG. 1, the database 41 provided with the host device 40 is stored in the DD files 41a, 41b, 41c and the external indicator 100 for accessing the field device 21 (PT100), the field device 22 (FT100), and the field device 23 (TT100). A DD file 41d to be accessed is stored.

  A simple dictionary file shown in FIG. 2 can be generated by using a part of the description of the DD file. The same applies to the case where the DD file provided in the parameter setting tool 60 is used.

DESCRIPTION OF SYMBOLS 10 Process fluid line 21, 22, 23 Field apparatus 30 Signal transmission line 40 Host apparatus 41 Database 41a, 41b, 41c, 41d DD file 100 External indicator 101 Database 101a, 102b, 102c Simple dictionary file 102 Communication processing means 103 User Interface 104 display means

Claims (5)

In an external indicating instrument that collects and displays parameter information provided by a plurality of field devices conforming to the Foundation Fieldbus (registered trademark) (hereinafter referred to as FF) standard connected to the fieldbus via the fieldbus.
A client / server type asynchronous communication means is provided for accessing and collecting the parameter information selected as a display item among the parameter information included in the field device at an arbitrary timing according to a user designation. External indicator instrument.   2. The external indicating instrument according to claim 1, wherein the client / server asynchronous communication means includes a simple dictionary file for accessing selected parameter information of the field device.   3. The external indicating instrument according to claim 1, wherein the simple dictionary file is constructed by engineering a host device connected to the fieldbus.   4. The simple dictionary file is constructed based on a Device Description (hereinafter referred to as DD) file for accessing all parameter information of field devices based on the FF standard provided in the host device. External indicating instrument as described in.   5. The parameter information collected by the client / server type asynchronous communication means is at least one of a device name of the field device, status information, alarm information, a process value, and a message. External indicating instrument according to any one of the above.