JP2012243008A - Process management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process management system which reconstructs a system with comparatively inexpensive cost, even when a HART communication compatible device is adopted.SOLUTION: The process management system includes: a HART communication compatible device 10 for transmitting/receiving a HART communication signal; a HART-IO unit 11 for transmitting a DC signal and a digital signal included in the HART communication signal received from the HART communication compatible device 10 to different systems respectively; a control system for receiving the DC signal transmitted from the HART-IO unit 11 through a communication bus 18; a monitoring system for receiving the digital signal transmitted from the HART-IO unit 11 through a communication cable 16; and an on-site terminal 21 capable of connecting to the HART-IO unit 11. The control system and the monitoring system are formed on the same network. The on-side terminal 21 acquires information about the HART-IO unit from the control system and the monitoring system through the communication cable 16.

Description

  The present invention relates to a process management system.

  At the site where production processes are managed, various field devices (for example, sensors and valves) having a transmission function are installed in the plant, and various production processes are managed by incorporating signals transmitted from the field devices into the system. ing. As a system for managing a production process, for example, there is a system that controls the opening degree of a valve based on a flow rate, temperature, pressure, or the like acquired from a sensor. In recent years, as a field device connected to such a process management system, a device equipped with a HART (Highway Addressable Remote Transducer) communication function (hereinafter referred to as “HART communication compatible device”) has been adopted. A HART communication-compatible device generates a signal generated by superimposing an alternating current signal representing a digital signal logic assigned to frequency signals of 1200 Hz and 2200 Hz on a direct current signal of 4 to 20 mA indicating a measured value or a control value ( Hereinafter, “HART communication signal” is input / output. That is, the HART communication-compatible device can exchange various information in addition to the measurement value and the control value. The following Patent Document 1 and Patent Document 2 disclose systems using HART communication-compatible devices.

JP 2003-186503 A Japanese Patent No. 4129715

  In the system of each patent document described above, a HART communication signal is used by a communication bus or a controller. In general, a communication bus and a controller of a process management system are designed on the assumption that a DC signal of 4 to 20 mA is used. Therefore, when using a HART communication signal in which a digital signal (AC signal) is superimposed on a DC signal of 4 to 20 mA with a communication bus or controller, the communication bus is replaced with a higher-speed communication bus, and the controller has a higher processing capacity. It needs to be replaced with a higher controller. However, exchanging the communication bus and controller requires a great deal of cost.

  The present invention has been made to solve the above-described problems caused by the prior art, and is a process capable of reconstructing a system at a relatively low cost even when HART communication-compatible equipment is employed. The purpose is to provide a management system.

  The process management system according to the present invention includes a HART communication compatible device having a HART communication function for transmitting and receiving a HART communication signal generated by superimposing a second signal on a first signal, the HART communication compatible device, and the HART communication signal. Are transmitted and received, and the first signal and the second signal included in the HART communication signal received from the HART communication-compatible device are transmitted to different systems, respectively, and transmitted by the input / output device. A control system that receives the first signal via the first line and controls the process based on the first signal, and the second signal transmitted by the input / output device via the second line. A monitoring system that receives and monitors the state of the HART communication-compatible device based on the second signal, and a terminal that can be connected to the input / output device or the second line The control system and the monitoring system are formed on the same network, and the terminal transmits information transmitted from the input / output device to the control system and the monitoring system, respectively, through the second line. Via the control system and the monitoring system.

  By adopting such a configuration, the control system is connected to the input / output device that transmits and receives the HART communication signal to / from the HART communication-compatible device via the first line, and the second path that is different from the first line is used. A monitoring system can be connected via a line. Thereby, in the input / output device, the monitoring system and the control system can be managed independently and separately.

  Moreover, it is good also as providing the telephone which can be connected on the said input / output device or the said 2nd line.

  Further, the first signal may be a DC signal of 4 to 20 mA, and the second signal may be an AC signal expressed by assigning logic of a digital signal to different frequency signals.

  According to the present invention, it is possible to provide a process management system capable of reconstructing a system at a relatively low cost even when a HART communication compatible device is employed.

It is a figure which illustrates the structure of the process management system in embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. However, the embodiment described below is merely an example, and does not exclude application of various modifications and techniques not explicitly described below. That is, the present invention can be implemented with various modifications without departing from the spirit of the present invention.

  First, the configuration of a process management system in the embodiment will be described with reference to FIG. As shown in FIG. 1, the process management system 1 includes HART communication-compatible devices 10i and 10o, input / output devices having a HART communication function (hereinafter referred to as “HART-IO units”) 11i and 11o, and field devices 12i. , 12o, IO units 13i, 13o, HUB 14, equipment monitoring device 15, controller 17, driving operation device 19, and on-site terminal 21.

  Note that the HART communication compatible devices 10i, 10o, the HART-IO units 11i, 11o, the field devices 12i, 12o, and the IO units 13i, 13o are compatible with HART communication unless they need to be distinguished from each other below. The device 10, the HART-IO unit 11, the field device 12, and the IO unit 13 are described.

  In the present embodiment, the HUB 14 and the device monitoring device 15 constitute a monitoring system that monitors the state of the HART communication-compatible device 10, and the controller 17 and the driving operation device 19 constitute a control system that controls the process.

  The equipment monitoring device 15 and the HART-IO unit 11 constituting the monitoring system are connected via a HUB 14 using, for example, an Ethernet (registered trademark) standard communication cable 16. The controller 17 and the HART-IO unit 11 and the IO unit 13 constituting the control system are connected by a communication bus 18, for example. The device monitoring device 15 and the driving operation device 19 are connected by, for example, an Ethernet (registered trademark) communication cable 20.

  As the HART communication-compatible device 10i and the field device 12i, for example, various sensors such as a flow rate sensor, a pressure sensor, and a temperature sensor can be used. On the other hand, as the HART communication-compatible device 10o and the field device 12o, for example, a valve such as a flow rate control valve or a pressure control valve or an actuator such as a pump or a fan can be used.

  The HART communication-compatible device 10 is a field device equipped with a HART communication function, and inputs and outputs a HART communication signal. The HART communication signal is a signal that is generated by superimposing an AC signal, which is expressed by assigning the logic of a digital signal to frequency signals of 1200 Hz and 2200 Hz, on a DC signal of 4 to 20 mA.

  The 4-20 mA DC signal is a signal indicating the value of one variable set for each HART communication-compatible device 10 or field device 12. Examples of variable values include measured values such as flow rate, pressure, and temperature, and control values such as valve opening. The digital signal is, for example, a signal indicating various data that can be collected in the HART communication-compatible device 10. Examples of the various data include process information in the HART communication compatible device 10 and hardware failure information incorporated in the HART communication compatible device 10. The measurement values and control values of the HART communication-compatible device 10 may be included in the various data.

  For example, the HART communication-compatible device 10 generates a HART communication signal as follows. First, the HART communication-compatible device 10 converts a digital signal represented by 1 and 0, for example, to a frequency signal of 1200 Hz and a frequency signal of 2200 Hz, respectively, and converts it into an AC signal. Subsequently, the HART communication-compatible device 10 superimposes the converted AC signal on a 4 to 20 mA DC signal indicating a measurement value, a control value, or the like. Thereby, a HART communication signal is generated.

  The HART-IO unit 11 is an input / output device that transmits / receives a HART communication signal to / from the HART communication-compatible device 10 and transmits / receives a 4-20 mA DC signal or a digital signal to / from the control system or the monitoring system. . The HART-IO unit 11 generates a 4-20 mA DC signal and a digital signal from the HART communication signal as follows, for example. First, the HART-IO unit 11 separates the received HART communication signal into an AC signal represented by a combination of a frequency signal of 1200 Hz and a frequency signal of 2200 Hz and a DC signal of 4 to 20 mA. Subsequently, the HART-IO unit 11 converts the separated AC signal into a digital signal represented by 1 and 0.

  The device monitoring device 15 receives the digital signal output from the HART-IO unit 11 via the communication cable 16 and the HUB 14. Based on the received digital signal, the device monitoring device 15 performs the process execution status in the HART communication compatible device 10, the failure status of the hardware incorporated in the HART communication compatible device 10, and the maintenance of the HART communication compatible device 10. Diagnose the time required for repair. The equipment monitoring device 15 displays a diagnosis result or the like on a monitor (not shown). Thereby, the operator can monitor the HART communication-compatible device 10. Further, the device monitoring device 15 transmits a hardware failure status or the like to the driving operation device 19 via the communication cable 20.

  The controller 17 controls the implementation state of the production process by monitoring and controlling the HART communication-compatible device 10 and the field device 12. Specifically, for example, the controller 17 sets the HART communication compatible device 10o or the field device 12o based on the measured values such as flow rate and pressure acquired from the 4-20 mA DC signal of the HART communication compatible device 10i or the field device 12i. By controlling with a DC signal of 4 to 20 mA, the opening of the valve is adjusted.

  The driving operation device 19 displays the operation details of the HART communication-compatible device 10 and the field device 12 on a monitor (not shown) based on the 4 to 20 mA DC signal received by the controller 17, and the alarm processed by the controller 17. To monitor. As a result, the operator can grasp the operation details of the HART communication-compatible device 10 and the field device 12. The driving operation device 19 operates the operating state of the HART communication-compatible device 10 or the field device 12 in accordance with an operator operation instruction. Examples of the operation contents in the operation state include adjustment of the opening degree of the valve and the like, start operation and stop operation of the device, and the like.

  As described above, in the process management system 1 according to the present embodiment, the control system is connected to the HART-IO unit 11 that transmits and receives the HART communication signal with the HART communication-compatible device 10 via the communication bus 18. The monitoring system can be connected via a communication cable 16 that is a different route. As a result, on the upper side of the HART-IO unit 11, the monitoring system and the control system can be managed independently and separately.

  Therefore, for example, even when a monitoring system is added to an existing system having only a control system, it is possible to add a monitoring system without using the control system and affecting the control system. Become. That is, it is not necessary to replace an existing communication bus or controller even when reconstructing from a system using a 4-20 mA DC signal to a system using a HART communication signal. Therefore, even when the HART communication-compatible device 10 is employed, the system can be reconstructed at a relatively low cost.

  The on-site terminal 21 shown in FIG. 1 is a terminal that can be appropriately connected to an arbitrary HART-IO unit 11 using a cable 22. The on-site terminal 21 may be, for example, a notebook personal computer or a portable information terminal.

  The on-site terminal 21 transmits information transmitted from the HART-IO unit 11 separately to the monitoring system and the control system via the communication cable 16, the HART-IO unit 11, and the cable 22 and the operation monitoring device 15. Obtained from each of the devices 19. Specifically, the site terminal 21 acquires an identification ID that uniquely identifies the HART-IO unit 11 from the connected HART-IO unit 11, and sends a request including this identification ID to the device monitoring device 15 and the driving operation. Transmit to device 19. The equipment monitoring device 15 and the driving operation device 19 that have received the request from the site terminal 21 transmit information corresponding to the identification ID included in the request to the site terminal 21. Thereby, the site terminal 21 can acquire information transmitted from the HART-IO unit 11 to the device monitoring device 15 and the driving operation device 19.

  Here, as described above, the HART-IO unit 11 transmits the information corresponding to the digital signal among the HART communication signals received from the HART communication compatible device 10 to the device monitoring device 15 via the communication cable 16 and the HUB 14. Send. On the other hand, the HART-IO unit 11 transmits information corresponding to a DC signal of 4 to 20 mA among the HART communication signals received from the HART communication compatible device 10 to the controller 17 via the communication bus 18. The information transmitted to the controller 17 is transmitted from the controller 17 to the driving operation device 19 via the communication cable 20.

  That is, the HART-IO unit 11 separates the information included in the HART communication signal received from the HART communication-compatible device 10 into two types of information, and transmits the separated information separately for the monitoring system and the control system. In such a process management system, for example, when a failure occurs in the monitoring system or the control system, a part or all of the information transmitted from the HART-IO unit 11 is stored in the device monitoring device 15 or the operation operation. There may be a situation where it is not transmitted to the device 19.

  When the information is not transmitted, a mismatch occurs between the information held by the HART communication-compatible device 10 or the HART-IO unit 11 and the information held by the device monitoring device 15 or the driving operation device 19. That is, there is a discrepancy between the contents that can be grasped by the workers on site and the contents that can be grasped by the system operator.

  When confirming the information held by the monitoring system or the control system from the site side, it may be possible for the worker to confirm the information while talking to the operator using a mobile phone or a transceiver. However, in this confirmation method, since wireless communication is performed in the plant, there is a possibility of affecting various electronic devices arranged in the plant. Therefore, it is not preferable to adopt this confirmation method.

  On the other hand, according to the process management system 1 in the present embodiment, the field terminal 21 connected to the HART-IO unit 11 accesses the device monitoring apparatus 15 via the communication cable 16 and the HUB 14, and further the communication cable. By accessing the driving operation device 19 via 20, the information transmitted by the HART-IO unit 11 from the device monitoring device 15 and the driving operation device 19 can be acquired. Thereby, the worker can compare the information acquired by the site terminal 21 with the information held by the HART communication-compatible device 10 and the HART-IO unit 11 deployed at the site. This comparison makes it possible to determine whether or not the information transmitted from the HART-IO unit 11 is definitely transmitted to the device monitoring device 15 and the driving operation device 19.

  Further, since the communication cable 16 is used as a route for accessing the device monitoring device 15 and the driving operation device 19, the processing of the control system using the communication bus 18 as a route is not burdened.

  Further, as described above, the communication cable 16 and the HUB 14 are used for communication between the device monitoring device 15 and the HART-IO unit 11, and the communication cable 20 is used for communication between the device monitoring device 15 and the driving operation device 19. Therefore, the on-site terminal 21 can realize communication with the device monitoring device 15 and the driving operation device 19 without newly providing a communication cable or a HUB.

[Modification]
In the above-described embodiment, the site terminal 21 is connected to the HART-IO unit 11, but the location to which the site terminal 21 is connected is not limited to the HART-IO unit 11. Other locations (for example, HUB 14) may be used as long as they are in the vicinity of the site where the worker is working and are on the communication cable 16 that connects the HART-IO unit 11 and the device monitoring device 15. When connecting the site terminal 21 to a device other than the HART-IO unit 11, for example, an identification ID that identifies the HART-IO unit 11 is input from the site terminal 21. The unit 11 may be specified.

  In the process management system 1 in the above-described embodiment, a wired connection type telephone may be connected to the HART-IO unit 11. As a result, when an on-site worker communicates with the operator, a telephone call can be made by wired communication without using wireless communication, which may affect electronic devices deployed in the plant. Absent. Further, the place where the wired connection type telephone is connected is not limited to the HART-IO unit 11, but may be another place (for example, HUB 14) similarly to the above-described field terminal 21.

  DESCRIPTION OF SYMBOLS 1 ... Process management system, 10 ... HART communication corresponding | compatible apparatus, 11 ... HART-IO unit, 12 ... Field device, 13 ... IO unit, 15 ... Equipment monitoring apparatus, 16 ... Communication cable, 17 ... Controller, 18 ... Communication bus, DESCRIPTION OF SYMBOLS 19 ... Driving device, 20 ... Communication cable, 21 ... Site terminal, 22 ... Cable.

Claims (3)

A HART communication-compatible device having a HART communication function for transmitting and receiving a HART communication signal generated by superimposing the second signal on the first signal;
An input / output device that transmits and receives the HART communication signal to and from the HART communication-compatible device, and transmits the first signal and the second signal included in the HART communication signal received from the HART communication-compatible device to different systems. When,
A control system for receiving the first signal transmitted by the input / output device via a first line and controlling a process based on the first signal;
A monitoring system that receives the second signal transmitted by the input / output device via a second line and monitors the state of the HART communication-compatible device based on the second signal;
A terminal connectable on the input / output device or the second line,
The control system and the monitoring system are formed on the same network,
The terminal acquires information transmitted from the input / output device to the control system and the monitoring system, respectively, from the control system and the monitoring system via the second line.
A process management system characterized by that.   The process management system according to claim 1, further comprising a telephone that can be connected to the input / output device or the second line.   The first signal is a DC signal of 4 to 20 mA, and the second signal is an AC signal expressed by assigning the logic of a digital signal to a different frequency signal. Process management system.

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