JPH0691656B2 - Distributed control system - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a distributed control system for monitoring and controlling various plants.

[Technical background of the invention and its problems]

Conventionally, as a system using an ITV camera, there is a monitoring system for monitoring an intruder on the premises as shown in FIG.
This system is divided into a field side A and a monitoring station side B. At each site on the field side A, there are cameras 1, ..., Camera platform, loudspeakers.
2, ..., Lighting 3, ..., Microphones, etc. are installed, and these are sequentially switched by the control device 5 on the site side in response to a command from the operation console 4 on the site side or a command from the monitoring station side B. No. 4 is displayed on the monitor television or is transmitted to the monitoring station side B via the transmission line 6.

The monitoring station side B includes an operation console 7 having an operation panel 7a, a monitor TV 7b, ... And a display panel 7c, as well as an operation console 7
Based on a command from the head side, a platform control signal is transmitted to the site A, or a video signal from the site A is received to determine the presence of an intruder, and if there is an intruder, an alarm signal is output. It is configured by a control device 8 having functions such as. It should be noted that several monitor televisions 7b on the monitoring station side B are normally used in view of cost, workability of operators, etc., and the ITV camera 1 on the site side A is switched and displayed.

However, the above configuration is only the ITV system and cannot be used as it is for controlling steel, petroleum, chemical plants and the like. In particular, in recent years, a distributed process control system in which a large number of stations are distributed and monitored by a higher-level device has become mainstream, and the monitoring of a plant in this system is performed by monitoring the temperature, pressure, flow rate, etc. from various sensors. The process amount is collected by data transmission and loop control is performed for each station, and the man-machine interface is performed by the operator console of the host device in the central monitoring room.

In such a system, conventionally, the system and the ITV system are generally installed separately and independently. The reason is that the video signal of the ITV camera and the process data have different signal properties and cannot be treated the same.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a distributed control system that comprehensively monitors and controls a plant by fusing an ITV system and a process data transmission system.

[Outline of Invention]

The present invention is an operator console station having a man-machine interface, a monitor device, etc., and a plurality of control stations having a television camera and a process control function, which are dispersedly connected using optical fibers and a star coupler to provide signals of a plurality of wavelengths. It is a distributed control system that exchanges signals between stations by using.

[One Embodiment of the Invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. First, FIG. 1 is a diagram schematically showing a distributed control system, in which an operator console station 11 on the central side and a control station 12, ..., Which controls a plurality of processes, serve as an optical transmission line. It has a configuration of a distributed control system which is connected to each other via a fiber 13 and a star coupler 14.

As the star coupler 14, for example, as shown in FIG. 2, a structure is used in which the light B incident from the branch ends is evenly distributed and emitted from a large number of branch ends. A pair of branch input terminals and branch output terminals are connected to each of the stations 11, 12 ,.

Next, FIGS. 3 and 4 are configuration diagrams of a more concrete system, and FIG. 3 is a control station 1
2, ... (for convenience, numbered 12A to 12D) is shown.
FIG. 4 shows the construction of the operator console station on the center side. This system uses an optical wavelength division multiplexing transmission system, and four wavelengths λ _{1 to} λ ₄ are used as an example.

12A and 12B of the control stations 12A to 12D
Have the same configuration, specifically, an optical-electrical converter 121 for converting the optical wavelength λ ₁ into an electric signal, and an operation terminal (not shown) for detecting the process amount and based on a command from the operator console station 11. Control section 122 for controlling the camera head and outputting the camera platform control signal, the frequency multiplexing circuit 123, and the pulse frequency modulation (P
FM) PFM section 124, electro-optical conversion section 125 using an LED or a diode for latching, and electro-optical conversion section 126
Further, the stations 12A and 12B are provided with a television camera 15 and a sound collecting microphone 16. This camera 15 and sound collection microphone 16 are frequency multiplexing circuits.
Although the video signal and the audio signal are frequency-multiplexed at 123, the television camera 15 may be used alone.
Further, the control station 12C is provided with three TV cameras 15, ..., The video switch 127 selectively outputs the three TV cameras 15, ... In response to a switching signal from the process control section 122. It is composed. Control station 12D, TV camera 1
It is a station that does not have the 5, ..., Sound collection microphones 16 and the like, but exclusively detects the process amount and controls the process operation end.

Further, in order to exchange signals between the control stations 12A to 12D and the operator console station 11, a multiplexer / demultiplexer 17 for multiplexing or demultiplexing a plurality of wavelengths at the input and output ends of each station 12A to 12D and a splice. Box 18A is provided. This splice box 1
8A is a multi-core optical fiber cord 19 and a single-core optical fiber cord
It is intended to protect the connection portion where 13 and 13 are spliced. 18B is for splicing the optical fiber cord 13 connected to each star coupler 14.

On the other hand, in the operator console station 11 on the center side shown in FIG.
There is a station 11A having a station and a station 11B having a man-machine interface, which may be operated independently of each other or may be operated by phase interpolation.

The station 11A is provided with a splice box 22 and a multiplexer / demultiplexer 23 on its input / output end side, and internally has an electric
Optical conversion unit 111, optical-electrical conversion unit 112, control unit for centralized management of process control data, process collection data, etc., transmission of camera selection signals, transmission of switching control signals, etc.
113, a plurality of optical-electrical conversion units 114, a demodulation unit 115 for demodulating a pulse frequency modulated signal, and a changeover switch 116. Reference numeral 24 is a separation circuit for separating the video signal and the audio signal when the audio signal is superimposed on the video signal.

Next, the other station 11B similarly has a splice box 22 and a multiplexer / demultiplexer 23 at its input / output ends.
It has an operator console 117 internally and an attached CRT
Monitor the entire plant by looking at the screen of display 25 and control it using the keyboard, and control as needed
Give instructions to 113. Reference numeral 118 is an electric-optical conversion section, and 119 is an optical-electrical conversion section.

FIG. 5 is a schematic diagram showing the system in a hierarchical manner and specifically shows the process control unit 122 in particular. The process control unit 122 uses the upper bus 31
The multiplexer 32 is provided at the input / output terminal of the ITV camera 15 and the communication controller 33 are connected to the multiplexer 32. Further, an internal bus 34 is derived from the communication controller 33, at least one or more process controllers 35, ... Are connected to the internal bus 34, and the controller 35 controls the platform of the television camera 15.

Next, the operation of the system configured as described above will be described. At the central operator console station 11, when an operator operates a keyboard on the operator console 117 to output a control signal to, for example, a particular control station, such as 12A, this is an electrical signal.
The optical signal is converted into an optical signal of wavelength λ _{1 by} the optical conversion unit 118, and is sent to the control station 12A via the star coupler 14 and the multi-core optical fiber cord 19 and the multiplexer / demultiplexer 17. In the control station 12A, the optical-electrical converter 121 converts the signal into an electric signal, and according to the content of the control signal, any one or two of requesting process amount data, controlling the operation end, or controlling the camera platform is performed. Upon receiving the data, the process control unit 122 converts the process amount data into an optical signal of wavelength λ ₁ by the electro-optical conversion unit 126 and transmits the data, or controls the process operation end, or controls the camera platform. Control to change the angle of the TV camera 15 with respect to the subject. Where the TV camera 15
If there is an audio signal from the microphone 16, the video signal from
Both signals are frequency-multiplexed by the frequency multiplexing circuit 123, and if only the video signal is output as it is, it is modulated to a pulse frequency by the subsequent PFM section 124, and this modulated signal is wavelength λ _{2 by the} electro-optical conversion section 125. It is converted to the light of and sent to the operator console 11 side. In this way, the wavelengths λ ₁ and λ ₂
Either one or both of the optical signals converted into the optical signal are transmitted to the operator console station 11 side via the optical fiber 19 and the star coupler 14.

On this operator console 11 side, station 11
Wavelengths λ ₁ , λ
₂ , the process amount data of the wavelength λ ₁ is entered into the control unit 113 and stored therein, and the video signal of the wavelength λ ₂ is converted into an electric signal by the optical-electrical conversion unit 114 and the demodulation unit 115 and demodulated. It At this time, the changeover switch 116 receives the changeover signal from the control unit 113 and displays the demodulated signal on the monitor television 21. In addition, the operator console 117 side also receives and stores the process amount data of the wavelength λ ₁ and performs necessary calculations to perform CRT display 2
Display on 5. It should be noted that, in relation to FIG. 5, the video signal of the television camera 15 is multiplexed with the data packet signal by the multiplexer 32 and transmitted to the upper bus 31 side.
Further, the camera platform control signal of the TV camera 13 is received by the process controller 35 through the communication controller 33, the internal bus 34, etc., and given to the TV camera 15 from the I / O card of the controller 35.

Therefore, according to the configuration of the above embodiment, if the optical fiber and the star coupler are used to perform signal transmission using optical signals having different wavelengths, the operator console station 11 is provided with a plurality of control stations 1.
It is possible to integrate the process control system and ITV system, in which 2, ... Are distributed, and it becomes possible to perform comprehensive supervisory control of the plant. Further, since the process amount data and the video signal are mutually transmitted using the same optical fiber cables 17 and 18, the cost can be reduced by the wiring amount of one signal. In addition, the number of TV cameras, the wavelength used, the monitor TV 24 used, and the like can be arbitrarily changed, so that a highly flexible system can be created. Further, since the pan head can be controlled by data transmission, the subject can be projected at a required angle and displayed on the TV monitor 21.

The present invention is not limited to the above embodiment.
The signal multiplexing means may be optical wavelength multiplexing after conversion to light.
The stations 11A and 11B may be divided into functions as necessary, or may be configured to operate independently of each other. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

〔The invention's effect〕

As described in detail above, according to the present invention, it is possible to provide a distributed control system in which the ITV camera system and the process control system can be integrated and the various plants can be monitored and controlled more effectively and flexibly.

[Brief description of drawings]

1 to 5 are for explaining one embodiment of the system of the present invention. FIG. 1 is a schematic diagram of a distributed control system using an optical fiber and a star coupler, and FIG. FIG. 3 is a conceptual block diagram of the star coupler shown in the figure, FIG. 3 is a specific block diagram of the local-side controller station, FIG. 4 is a specific block diagram of the center-side operator / console station, and FIG. FIG. 6 is a schematic diagram of a conventional ITV camera system. 11 …… Operator console station, 12 (12A
~ 12D) …… Control station, 13 …… Optical fiber, 14 …… Star coupler, 15 …… TV camera, 16…
… Sound collection microphone, 17 …… Multiplexer, 18A, 18B …… Splice box, 21 …… Monitor TV, 22 …… Splice box, 23 …… Multiplexer, 25 …… CRT display, 113
...... Control section, 115 ...... Demodulation section, 116 ...... Changeover switch, 117 ...... Operator console, 122 ...... Process control section, 123 ...... Frequency multiplexing circuit, 124 ...... PF
M section (pulse frequency modulation section).

Claims (1)

[Claims] 1. A distributed control system in which a plurality of control stations are distributedly arranged on an operator console station via transmission lines, and in addition to a device including at least a television camera, a controller unit having a control function of the device and a process. A plurality of control signals for controlling the equipment and signals relating to the process, which are different for each control station, are transmitted and received by an optical signal having a first wavelength, and which are output from the plurality of equipments. A plurality of control stations for frequency-multiplexing signals, converting the multiplexed signals into optical signals of a second wavelength and outputting the optical signals; and a first of the signals related to the process output from each of the control stations. The optical signal of the wavelength and the output from each control station And a man-machine interface and a monitor device for transmitting the optical signal of the second wavelength, which is the frequency-multiplexed signal of the receiver, through the one optical fiber as the transmission line by wavelength multiplexing, While converting a control signal required for controlling the device and the process by designating a control station into an optical signal of the first wavelength and transmitting the optical signal to the controller unit via the optical fiber, the transmitting unit A first wavelength and a second wavelength transmitted via the optical fiber are demultiplexed, and a process-related signal which is an optical signal of the first wavelength is fetched and stored in each control station. And the operator console station for demodulating frequency multiplexed signals from a plurality of devices which are optical signals of the second wavelength. Distributed control system characterized by comprising and.