JP2003186503A - Process control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process control system, capable of connecting to process equipment with special types, such as HART (Highway Addressable Remote Transducer) equipment. <P>SOLUTION: The system, performing process control based on process signals acquired from a sensor device, where the sensor device outputs modulated digital signals and analog signals of process values and communicates through the modulated digital signals, and the system comprises a communication means for communicating according to the protocol of the sensor device and a signal processor for processing signals specific to the sensor device. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a process control system for controlling a plant based on a process signal obtained from a sensor device existing in the plant. More specifically, for example, HART (Highway Addressable)
Remote Transducer) relates to a process control system that has been devised so that it can be connected to a sensor device that communicates according to the communication protocol.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a configuration example of a conventional process control system. In FIG. 5, the operation monitoring station 1 and the control station 2 are connected to the communication bus 3. Control station 2 is operation monitoring station 1
The plant 4 is controlled under the monitoring of. The operation monitoring station 1 is in charge of operation and monitoring of the plant. A plurality of control stations are distributed in the plant according to the scale of the plant.

Sensor devices 41, 4 existing in the plant 4
2 detects process values such as temperature, pressure and liquid level. The openings of the valves 43 and 44 are controlled by an operation signal given from the control station 2. Sensor device 41, 4
The analog signal of 4 to 20 mA and 1 to 5 V output by the controller 2 is input to the control station 2. Based on this input, the control unit (not shown) in control station 2
Control calculation is performed to obtain the manipulated variable. This operation amount is 4 to 2
It is output as an analog signal of 0 mA and 1 to 5 V, and the opening of the valves 43 and 44 is controlled by this output. For example, the process amount such as temperature and pressure is controlled by controlling the valve opening of the reaction kettle.

As a sensor device, there is a HART device, for example. The HART device outputs the modulated digital signal from 4 to
A signal superimposed on an analog signal having a process value of 20 mA or the like is output. Communication is performed by superimposing the modulated digital signals according to a predetermined communication protocol. In chronological order, first, the digital signal corresponding to the start bit is superimposed, then the digital signal forming the communication data is superimposed, and finally, the digital signal corresponding to the end bit is superimposed. A communication frame is composed of the start bit, communication data, and end bit. The presence or absence of a digital signal corresponds to 1,0 information.

However, conventionally, in the process control system for communicating with the sensor device other than the HART device, the HART device has been used.
Since there is no input / output module equipped with a function capable of communicating with a device, it is impossible to simultaneously handle an analog signal of 4 to 20 mA or the like and unique data (as a HART variable) output from a HART device. Moreover, since the function of capturing the output data of the HART device in the system is not supported, the HART variable cannot be captured in the system. For this reason, the conventional process control system cannot be connected to the HART device.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it processes a signal unique to a communication device and a communication device that performs communication in accordance with the communication protocol of the sensor device. It is an object of the present invention to realize a process control system that can be connected to a sensor device of a specific type such as a HART device by providing a signal processing unit that operates.

[0007]

The present invention is a process control system having the following configuration.

(1) In a process control system for performing process control based on a process signal obtained from a sensor device, the sensor device outputs a modulated digital signal and an analog signal of a process value, and the modulated signal is output. A process which is a sensor device that communicates with a digital signal, and has a communication unit that performs communication according to a communication protocol of the sensor device, and a signal processing unit that processes a signal unique to the sensor device. Control system.

(2) The process control system according to (1), wherein the sensor device is a HART device.

(3) The display block has builder means for defining the terminals of the display block to which the unique data obtained from the sensor device is assigned, and the display block has the predetermined data for the unique data assigned to its own terminal. And displaying on the display means.

(4) The sensor device is connected, and an input / output module for inputting / outputting a signal to / from the connected sensor device, and a plurality of sensor devices are connected to one terminal of the input / output module. (1), the polling address is defined when the sensor is connected, and the polling address is not defined when one sensor device is connected to one terminal. system.

(5) The process control system according to (4), wherein the input / output module has a modulation / demodulation means for HART demodulating an input signal and HART modulating an output signal.

(6) Definition means for creating configuration data defining which data in which sensor device is to be monitored, and the created configuration data are downloaded, and the sensor device is based on the downloaded data. A process control system according to (1), further comprising: a communication unit that performs communication and acquires desired data.

(7) An abnormality display means for displaying at least one of an abnormality of the sensor device, an abnormality of communication with the sensor device, an abnormality of a communication command of the sensor device, and an abnormality of the input / output module in a system alarm window. The process control system as described in (1) or (4) above.

(8) When communicating with the sensor device,
The process control system according to (1), further comprising history storage means for detecting a state of the device and storing the detected state as a historical message.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, the operation monitoring station 10, the equipment management station 20, the engineering workstation (referred to as EWS) 30, and the control unit 50 are connected to a communication bus 60. The communication unit 51 is provided in the control unit 50, and is provided to perform communication between the operation monitoring station 10, the device management station 20, the EWS 30, and the sensor device.

Control unit 50 and input / output module 70
Are connected to the communication bus 80. The input / output module 70 includes sensor devices such as HART devices DEV1 and D.
EV2 and DEV3 are connected. In the example of the figure, one HART device DEV1 is connected to one terminal of the input / output module 70. Two HART devices DEV2 and DEV3 are connected to one terminal.
A connection in which one HART device is connected to one terminal is called a point-to-point connection. A connection in which multiple HART devices are connected to one terminal is called a multi-drop connection. The input / output module 70 is HA
Input and output signals to and from the RT devices DEV1, DEV2, and DEV3.

In response to a request from the operation monitoring station 10, the control unit 50 makes an immediate access to the input / output module 70 and acquires data from the HART devices DEV1 to DEV3. The data acquired from the HART device is called a HART variable. The HART variable is, for example, H
If the ART device is a temperature transmitter, it consists of four data, and the measurement temperature of measurement channel 1, the measurement temperature of measurement channel 2, the temperature of the sensor device itself, and the data of the temperature difference between measurement channel 1 and measurement channel 2 are included. It is assigned. The data of the acquired HART variable is used in the operation monitoring station 1
Displayed as 0. In addition, the operation monitoring station 10
In addition to HART variable data, HART devices DEV1 to DEV1
The message acquired by communicating with the DEV3, the operating state of the input / output module 70, and the like are displayed.

In response to a request from the device management station 20, the control unit 50 makes a request-type access to the input / output module 70 and acquires device parameters from the HART devices DEV1 to DEV3. Parameters are acquired by on-demand communication. Device management station 20
Displays the acquired parameters. The EWS 30 defines how to connect the input / output module 70 and the HART devices DEV1 to DEV3. The defined data (configuration data) is downloaded to the communication means 51 (configuration download). Communication means 51
HART device D based on downloaded data
Communicates with EV1 to DEV3.

FIG. 2 is a diagram showing a concrete configuration example of the system of FIG. 2 that are the same as those in the previous figure are given the same symbols. The display means 11 provided in the operation monitoring station 10 displays a screen necessary for operating and monitoring the plant. The abnormality display means 12 displays an abnormality of the HART device, an abnormality of communication with the HART device, an abnormality of the communication command of the HART device, an abnormality of the input / output module 70, etc. in the system alarm window. The system alarm window is displayed by the display means 11. History storage means 1
3 detects the state of the device when communicating with the HART device, and stores the detected state as a historical message. The historical message is displayed on the display means 11 as needed. The operating state monitoring means 14 monitors the operating state of the input / output module 70. The monitoring result is displayed on the display unit 11 for each module, for example.

The display means 21 provided in the device management station 20 displays a screen for managing the HART device. The parameter collection unit 22 collects device parameters from HART devices by on-demand communication.
By displaying the collected parameters on the display unit 21, the operator can recognize the HART device existing in the plant.

The display means 31 provided in the EWS 30 is
Display the screens required for engineering work. The defining means 32 defines a polling address when a HART device is multi-drop connected to the terminal of the input / output module 70, and does not define a polling address when the HART device is point-to-point connected. In the illustrated example, the input / output module 70 includes a HART.
Device DEV1 is connected point-to-point, H
The ART devices DEV2 and DEV3 are multi-drop connected. No polling address is defined for the HART device DEV1, and the HART devices DEV2 and DEV3 are not defined.
Defines a polling address for.

Further, the defining means 32 creates configuration data defining which data in which HART device is to be monitored. For example, the sensor device DE
The measurement temperature of the measurement channel 1 of V2 is defined as monitoring data. At this time, the measured temperature of the measurement channel 1 of the sensor device DEV2 is acquired by immediate access and sent to the operation monitoring station 10.

The new creating means 33 defines an input / output module newly created in the engineering work. The builder means 34 defines the terminals of the display block to which the HART variable is assigned, in addition to the attribute definition of the analog signal of 4 to 20 mA and 1 to 5V. The display block displays the HART variable assigned to its own terminal on the display means 31 in a predetermined screen configuration, for example, a face plate. The display block is mounted on the operation monitoring station 10. This will change the HART variable from 4 to 20m.
It has become possible to handle it in the same manner as analog signals of A and 1 to 5V. The test means 35 exchanges virtual communication data with the HART device to test the HART device.

The signal processing unit 51 provided in the control unit 50 performs signal processing unique to the HART device in addition to signal processing of analog signals of 4 to 20 mA and 1 to 5V.
The communication unit 52 downloads the configuration data created by the defining unit 32, communicates with the HART device based on the downloaded data, and acquires desired data. The communication frame creating means 53 uses the HAR
A communication frame conforming to the communication protocol of the T device is created. This communication frame has a structure including a start bit, communication data, and an end bit.

The module monitoring means 54 monitors the state of the input / output module 70. The monitoring result is sent to the operation monitoring station 10. The report creating means 55 creates a report recording the monitoring result of the state of the input / output module 70. The test means 56 conducts a communication test with the HART device.

The input / output module 70 has a modulator / demodulator that HART demodulates the input signal and HART-modulates the output signal. By providing modulation / demodulation means, H
Even if the ART device and the process control system handle different types of signals, they can communicate with each other.

FIG. 3 is a diagram showing a concrete configuration example of the input / output module of FIG. In the example of FIG. 3, 16 HARs
The T devices DEV1 to DEV16 are connected to the input / output module 70. The multiplexer 71 selects signals from the HART devices DEV1 to DEV16. Modem 7
2 shows the signal input to the input / output module 70 by HAR
T demodulates and sends to the control unit 50. In addition, the signal output from the input / output module 70 is HART-modulated for HAR.
Send to T equipment. The multiplexer 73 is the modulation / demodulation means 72.
Select the signal demodulated in. The selection state is switched between when the demodulated signal is the HART variable and when it is the parameter of the HART device. As a result, the HART variable and the parameter of the HART device are sorted and acquired. It should be noted that the analog signal of the process value is obtained without passing through the modulation / demodulation means.

FIG. 4 shows an example of the EWS definition screen. In FIG. 4, "terminal number" is a logical terminal number provided for operation monitoring. "Device connection point" is HAR
This is the terminal number of the input / output module to which the T device is connected. “Data type” indicates the type of data to be handled. "P
"V" is the first data of the HART variable, "SV" is HAR
This is the second data of the T variable. The "polling address" describes the polling address when the HART device is in the multi-drop connection. For example, the terminal number "%
Z031201 ", the first data P in the HART device connected to the terminal number" 1 "of the input / output module
Allocate V. The second data SV in the HART device connected to the terminal number “1” of the input / output module is assigned to the terminal number “% Z031202”. In the illustrated example, the HART device is connected point-to-point, so no polling address is assigned. The 1st data to the 4th data of the HART variable are, for example, the measurement temperature of the measurement channel 1 and the measurement channel 2
Data of the measurement temperature, the temperature of the sensor device itself, and the temperature difference between the measurement channel 1 and the measurement channel 2. In this way, the connection between the terminals of the input / output module and the HART device is defined.

In the embodiment, the case where the sensor device is a HART device has been described, but the sensor device may be any other device that outputs an analog signal of a process value and a digital signal for communication. .

[0031]

According to the present invention, the following effects can be obtained.

According to the first aspect of the invention, the communication means for performing communication according to the communication protocol of the sensor device and the signal processing section for processing the signal unique to the sensor device are provided. Therefore, the process control system can be connected with the sensor device that outputs a signal that superimposes the modulated digital signal on the analog signal of the process value and superimposes the modulated digital signal according to the prescribed communication protocol for communication. become.

According to the second aspect of the invention, the HART device and the process control system can be connected.

According to the third aspect of the invention, the terminals of the display block to which the unique data obtained from the sensor device are assigned are defined. Therefore, the data unique to the sensor device is
It can be displayed in the same manner as an analog signal of -20 mA and 1-5V.

According to the fourth aspect of the invention, when a plurality of sensor devices are connected to one terminal, a polling address is defined, and when one sensor device is connected to one terminal. Does not define a polling address. As a result, it is possible to communicate with the sensor device regardless of the connection form of the point-to-point connection and the multi-drop connection.

According to a fifth aspect of the invention, the input / output module has a modulator / demodulator for HART demodulating an input signal and HART modulating an output signal. Therefore, it becomes possible to communicate between the HART device and the process control system having different signal formats.

According to the sixth aspect of the invention, since the communication means communicates with the sensor device based on the configuration data defining which data in which sensor device is to be monitored, desired data can be easily obtained. Can be obtained.

According to the invention of claim 7, since at least one of the abnormality of the sensor device, the abnormality of communication with the sensor device, the abnormality of the communication command of the sensor device, and the abnormality of the input / output module is displayed on the system alarm window, various types are displayed. The abnormality of can be easily recognized.

In the eighth aspect of the present invention, the state of the device is detected when communicating with the sensor device, and the detected state is stored as a historical message. Therefore, when an abnormality occurs in the sensor device, the cause of the abnormality can be analyzed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a specific configuration example of the system of FIG.

FIG. 3 is a diagram showing a specific configuration example of the input / output module of FIG.

FIG. 4 is a diagram showing an example of an EWS definition screen.

FIG. 5 is a diagram showing a configuration example of a conventional process control system.

[Explanation of symbols]

10 Operation monitoring station 12 Abnormality display means 13 History storage means 30 EWS 32 definition means 34 Builder Means 50 control unit 51 signal processor 52 communication means 70 I / O module 72 modulation / demodulation means DEV1 to DEV3 HART equipment

Claims (8)

[Claims] 1. A process control system for performing process control based on a process signal obtained from a sensor device, wherein the sensor device outputs a modulated digital signal and an analog signal of a process value, and the modulated digital signal. A sensor device that communicates by a signal, a communication means that performs communication according to the communication protocol of this sensor device, and a signal processing unit that processes a signal unique to this sensor device,
A process control system comprising: 2. The process control system according to claim 1, wherein the sensor device is a HART device. 3. A builder means for defining a terminal of a display block to which the unique data obtained from the sensor device is assigned, the display block having the unique data assigned to its own terminal in a predetermined screen configuration. 2. The process control system according to claim 1, wherein the process control system displays the result on a display means. 4. An input / output module to which the sensor device is connected and which inputs and outputs signals to and from the connected sensor device, and a plurality of sensor devices are connected to one terminal of the input / output module. 2. The process control system according to claim 1, further comprising: defining means for defining a polling address when a sensor device is connected to one terminal, and defining means for defining a polling address when one sensor device is connected to one terminal. . 5. The process control system according to claim 4, wherein the input / output module has a modulator / demodulator for HART demodulating an input signal and HART modulating an output signal. 6. A definition means for creating configuration data defining which data in which sensor device is to be monitored, and the created configuration data is downloaded and communicates with the sensor device based on the downloaded data. The process control system according to claim 1, further comprising: a communication unit configured to perform the above process and acquire desired data. 7. An abnormality display means for displaying at least one of an abnormality of the sensor device, an abnormality in communication with the sensor device, an abnormality in a communication command of the sensor device, and an abnormality in the input / output module in a system alarm window. The process control system according to claim 1 or 4, characterized by the above-mentioned. 8. The process control system according to claim 1, further comprising a history storage unit that detects a state of the device when communicating with the sensor device and stores the detected state as a historical message.