JPH07336362A - Supervisory and controlling device - Google Patents

Abstract

PURPOSE:To improve the reliability of a transmission system without interrupting transmission by radio communication even when the disconnection accident or the like of transmission line occurs. CONSTITUTION:From a centeral station M1 to respective terminal stations T1 to T3, a command for monitoring whether or not information is normally transmitted is transmitted in a fixed cycle. When the disconnection accident is generated in interstation parts B and C in the transmission line 1, when the transmission/reception part 4 of the terminal station T2 judges that the reception level of the command is turned lower than a prescribed value, a radio equipment 3 transmits signals from a CPU 5 by the judgement and performs the radio communication to the central station M1. When the disconnection accident is recovered and the transmission returns to normal, when the transmission/reception part 4 judges that the reception level of the command is more than the prescribed value, the radio equipment 3 stops transmitting the signals from the CPU 5 by the judgement. Thus, the terminal station T2 stops performing the radio communication with the central station M1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supervisory control device for supervising and controlling equipment and the like arranged in various places of a facility.

[0002]

2. Description of the Related Art Modernized facilities such as buildings, plants and highway networks have many equipments, and it is necessary to operate these equipments in cooperation with each other for smooth operation of the facilities. Needed above. Therefore, it is desirable to be able to monitor the operating conditions of all equipment at a specific location and control all equipment from this particular location. Normally, a monitoring control device is used for the monitoring and control.

As shown in FIG. 2, for example, a conventional supervisory control apparatus includes a central station M ₁₁ and a plurality of terminal stations T _{11 to} T ₁₃ , which are continuously connected by a ring-shaped transmission line 11. It is configured to be connected. The transmission line 11 is generally a metal conductor wire for electrical transmission or an optical fiber for optical transmission. Further, the transmission line 11 is configured in a double loop shape of an active system 11a and a standby system 11b. on the other hand,
The central station M ₁₁ and the terminal stations T _{11 to} T ₁₃ each have a transmission device 12 that sends out information to the transmission line 11 and takes in information from the transmission line 11.

In the above supervisory control device, normally, the active system 1
Communication is sequentially performed among the stations M ₁₁ and T _{11 to} T ₁₃ through 1a, and when communication in the active system 11a becomes impossible, communication is performed through the standby system 11b.

[0005]

[Problems to be Solved by the Invention] However, each station M ₁₁
The wiring of the transmission line 11 between T _{11 and} T ₁₃ is generally the active system 1
Since the 1a and the standby system 11b are laid together and performed, it is highly likely that both the active system 11a and the standby system 11b will be disconnected when a disconnection accident occurs. While the case where the transmission line 11 only on the side is broken, the information received by the terminal station T ₁₁ is transmitted from the central station M ₁₁ of the terminal station T ₁₂ as shown in the figure P is sent to the terminal station T ₁₂ However, due to the loopback function, it is transmitted from the terminal station T ₁₁ to the terminal station T ₁₂ via the central station M ₁₁ and the terminal station T ₁₃ .

However, when the transmission line 11 is broken on the other side of the terminal station T ₁₂ as shown by Q in the figure,
Transmission from the terminal station T ₁₃ by the loopback function becomes impossible. Therefore, in this case, the terminal station T ₁₂ is in an isolated state and cannot communicate with other stations at all.

The present invention has been made in view of the above circumstances, and in the case of the above-mentioned disconnection accident,
It is an object of the present invention to provide a supervisory control device that enables communication.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a supervisory control device of the present invention is designed so that a plurality of control stations for monitoring and controlling equipments respectively perform transmission and reception. A monitoring and control device that communicates via a transmission line provided with a system is characterized by the following means.

That is, in the above supervisory control device, the control station communicates wirelessly so that the control station can receive at all times and a reference signal transmitted from a specific control station through the transmission line at a constant cycle. Level determining means for determining whether or not the reception level of the reference signal is lower than a predetermined value, and when the level determining means determines that the reception level of the reference signal is lower than the predetermined value, while permitting transmission by the wireless communication means, Transmission control means for prohibiting transmission by the wireless communication means when the level determination means determines that the reception level of the reference signal is equal to or higher than a predetermined value.

[0010]

In the above structure, communication is normally performed between the control stations via the transmission line. For example, in a system using a ring-shaped transmission line, when one control station transmits information, the next station receives the information and transmits it to the next station. By repeating such transmission and reception, the information returns to the transmission source control station. Even when each control station is the transmission source, the transmission is similarly performed. In the above system, the transmission line connecting between the control station on the transmission side and the control station on the reception side is a transmission line for transmission to the control station on the transmission side, and to the control station on the reception side. Is a transmission line for reception.

When a transmission line formed in a radial pattern is used, a plurality of control stations (terminal stations) are connected to a control station (central station) via the transmission line, and information is sent from the central station. When transmitted via a trusted (for each terminal station reception) transmission line, each terminal station receives that information. vice versa,
When transmitting information from each terminal station, the information is transmitted via a transmission line for transmission (for the central station, reception) and received by the central station.

By the way, in the above system, a reference signal is transmitted from a specific control station at a constant cycle in order to monitor whether or not a transmission system including a transmission line is normally transmitting. If the transmission system is normal, the level of the reference signal will not drop, so the level determination means determines that the reception level is equal to or higher than a predetermined value. Therefore, in this case, communication by the transmission line is maintained.

When the transmission line is broken or the level of the transmission signal is lowered, the level determination means determines that the reception level of the reference signal is lower than a predetermined value. In this case, communication via the transmission line is impossible (or difficult). Then, based on the above determination, the transmission control unit permits the transmission of the wireless communication unit. Further, in each control station, since the wireless communication means can always communicate, when the transmitting side can transmit the wireless communication means as described above, the control station that cannot communicate by the transmission line and the other control station The wireless communication is performed between the wireless communication terminal and the wireless communication terminal.

On the other hand, when the disconnection of the transmission line and the level decrease of the transmission signal are eliminated and the normal state is restored, the transmission by the transmission line becomes possible, while the level determination means makes the signal level equal to or higher than a predetermined value. It is determined that there is. Then, based on this determination, the transmission control means prohibits the transmission of the wireless communication means.

As described above, since wireless communication is performed with respect to the control station which cannot communicate with the transmission line, the control station does not lose communication with other stations. Also,
When the communication via the transmission line becomes possible, the wireless communication is stopped, so that the wireless communication, which is inferior in reliability of information transmission to the transmission line, is not maintained.

Therefore, when the communication by the transmission line becomes impossible or difficult, it is possible to temporarily substitute the wireless communication during the restoration work of the transmission line to maintain the communication between the stations.

[0017]

EXAMPLE An example of the present invention will be described below with reference to FIG.

As shown in FIG. 1, the supervisory control apparatus according to this embodiment comprises a central station M ₁ as a control station and a plurality of terminal stations T _{1 to} T ₃ . Central station M ₁ and terminal station T ₁ ~
T ₃ and T ₃ are continuously connected by the transmission line 1 in this order. The transmission line 1 forms a double loop consisting of a working system 1a and a standby system 1b, and is usually composed of a twisted pair line for electrical transmission and an optical fiber cable for optical transmission. It is configured. The transmission line 1 includes a central station M ₁ and a terminal station T ₁ , a terminal station T ₁ and a terminal station T ₂ , a terminal station T ₂ and a terminal station T _3, and a terminal station T ₃ And the central office M ₁ are individually divided into inter-office portions A to D.

The central station M ₁ and the terminal stations T _{1 to} T ₃ respectively have a transmission device 2 and a radio device 3. The transmission device 2 has a transmission / reception unit 4 and a CPU 5, and is connected to the transmission / reception unit 4 to two adjacent inter-office units A to D. Although the transmission / reception unit 4 and the CPU 5 are shown only for the terminal station T ₂ for the sake of convenience, the transmission apparatus 2 at the central station M ₁ and the terminal stations T ₁ and T ₃ is also configured in the same manner.

The transmitting / receiving section 4 is connected so as to communicate with the CPU 5, and receives a signal transmitted via the transmission line 1 while transmitting a signal to the next station. If the transmission / reception unit 4 is a system that transmits electric signals, the electric signals are transmitted to the CPU 5. On the other hand, the transmission / reception unit 4 is an optical / electrical conversion function for converting an optical signal to an electric signal and transmitting the electric signal to the CPU 5, and an electric / electrical conversion function for converting the signal from the CPU 5 into an optical signal, in the case of a system that transmits an optical signal. / Has a light conversion function.

Further, the transmitting / receiving section 4 is adapted to determine whether or not a command (reference signal), which will be described later, transmitted from the central station M _{1 at a} constant cycle is lower than a predetermined level, and serves as a level determining means. It has the function of. In particular,
The transmission / reception unit 4 outputs the determination signal of "1" when the reception level of the reference signal is lower than the predetermined value, and outputs the determination signal of "0" when the reception level of the reference signal is equal to or higher than the predetermined value. Has become.

The CPU 5 mainly has a function of controlling transmission. The CPU 5 determines whether or not the received signal from the transmitter / receiver 4 is addressed to its own station, captures the received signal addressed to its own station, and returns it to the transmitter / receiver 4, while sending it to another station. The received signal addressed to the transmitter / receiver 4 is returned without being taken in.

When the CPU 5 receives a command transmitted from the control unit 9 of the central station M ₁ which will be described later and transmitted through the active system 1a and the standby system 1b, the CPU 5 transfers the command to the next station, and the next station receives the command. If there is a response to the command, it confirms that the operation and transmission system of the next station are normal, while if there is no response from the next station to the command, it includes the inter-station portions A to D of the transmission line 1 and the transmission device 2. A loopback is formed in the transmission / reception unit 4 after confirming an abnormality in the transmission system. In addition, the CPU 5 responds to the command to the other station on the command transmitting side when it becomes the receiving side of the above command.

The wireless device 3 as a wireless communication means has a transmission / reception function and a modulation / demodulation function so as to perform wireless communication between the stations, and is configured to be constantly receivable. This wireless device 3 is connected to the CPU 5,
The signal from the CPU 5 is always supplied. Further, the wireless device 3 transmits the input signal in response to the determination signal of “1” from the transmission / reception unit 4, but does not transmit the input signal in response to the determination signal of “0” from the transmission / reception unit 4. That is, the wireless device 3 has a function as a transmission control unit.

Each of the terminal stations T _{1 to} T ₃ has a control section 6. The control unit 6 includes a CPU 7 and an input / output device (in the figure,
I / O) 8 (for convenience, only T ₂ is shown in the figure). The CPU 7 is communicably connected to the CPU 5 and controls input / output. For more information,
The CPU 7 provides the control output from the CPU 5 to the input / output device 8, receives the observation data and the like from the input / output device 8, and transfers the observation data to the CPU 5. The input / output device 8 is connected to various equipments (not shown), and relays the transfer of information between these equipments and the CPU 7.

The central station M ₁ has a control unit 9. The controller 9 controls communication with a host machine (not shown), and has a host interface (not shown) for connecting to the host machine. Further, the control unit 9 is adapted to issue a command for confirming whether or not the transmission is normally performed to the terminal stations T _{1 to} T _{3 with} a carrier wave of a constant cycle.

In the supervisory control device configured as described above, the information transmitted from the central station M ₁ is normally transmitted through the active system 1a to the terminal stations T _{1 to} T ₃ in that order.
Return to central station M ₁ . For example, when the terminal station T ₂ is designated as the destination of information, while the information is transmitted as described above, the information is taken in by the transmission device 2 in the terminal station T ₂ and given to the control unit 6. . Further, the transmitted information is the terminal station T ₁ · T that is not the destination of the information.
_{By 3} , it is judged from the address included in the information that it is not addressed to the own station, and it is transmitted to the next station.

[0028] Here, for example, if a disconnection fault occurs in the inter-station section B to the working system 1a and the backup system 1b, the above command issued by the central station M _1, the terminal station via the terminal station T ₁ Although it is transmitted to T _2, there is no response to the command from the terminal station T ₂ due to the disconnection of the transmission line 1. Then, a loopback is formed by the transmission device 2 of the terminal station T ₁ , and the information transmitted from the central station M _{1 is} transferred to the backup system 1
It is returned to the central office M ₁ through b. Then, the information is transmitted from the central station M ₁ to the terminal station T ₃ through the backup system 1b, further to the terminal station T ₂ , and then to the terminal station T ₂
By returning to the terminal station T through the active system 1a
It is returned to the central station M ₁ via ₃ .

Further, when a disconnection accident occurs in the inter-office section B / C in the active system 1a and the standby system 1b, or when the optical signal level is lowered in the case of optical transmission, the terminal station T ₃ due to loopback is used. through it becomes impossible for transmission to the terminal station T _2. In this case, in the terminal station T ₂ , the transmission / reception unit 4 determines that the reception level of the command has become lower than a predetermined value, and outputs a determination signal of “1”. Upon receiving the determination signal, the wireless device 3 can transmit the signal from the CPU 5. As a result, information is transmitted from the terminal station T ₂ to the central station M ₁ .

When the above-mentioned inconvenience in transmission is repaired and the transmission returns to normal, the transmitting / receiving unit 4 determines that the command reception level is equal to or higher than a predetermined value, and "0".
Is output. Then, when the wireless device 3 receives the determination signal, the signal from the CPU 5 cannot be transmitted. This prevents information transmission from the terminal station T ₂ to the central station M ₁ .

As described above, in the supervisory control device according to the present embodiment, as described above, when transmission by all of the transmission lines 1 connected to a certain station becomes impossible or difficult, communication between stations is performed. Then, wireless communication is automatically performed by the wireless devices 3.3. This makes it possible to avoid an unexpected situation in which information transmission is interrupted due to a disconnection accident or the like.

In this embodiment, the wireless communication between the central station M ₁ and the terminal station T ₂ has been described. However, the wireless communication between the terminal stations and the central station M ₁ and the terminal station T ₁ or the terminal station T _{2 are performed.} T
It goes without saying that the wireless communication with ₂ is also possible in the same manner as above.

Further, in the present embodiment, an example in which the transmission line 1 formed in an annular shape is adopted has been described, but the present invention is not limited to the above-mentioned configuration in which the transmission line 1 is adopted. As an example, although not shown, there is a system in which a central station and a plurality of terminal stations are connected by a radial transmission line in a one-to-many relationship. In such a system, the transmission line connected between the central office and each terminal station is
It is composed of two systems, a working system and a backup system, which are capable of round-trip transmission.

[0034]

As described above, the supervisory control apparatus of the present invention has a plurality of control stations that monitor and control facility equipment, each of which is capable of always receiving wireless communication means for performing wireless communication, and a specific communication station. Level determination means for determining whether or not the reception level of the reference signal transmitted from the control station via the transmission line at a constant cycle is lower than a predetermined value, and the reception level of the reference signal is lower than the predetermined value by the level determination means. When it is determined to be low, the wireless communication means permits the transmission, while when the level determination means determines that the reception level of the reference signal is equal to or higher than a predetermined value, the transmission control means prohibits the wireless communication means to transmit. It has and.

As a result, when a control station becomes unable to communicate by the transmission line due to a disconnection of the transmission line, a decrease in the level of the transmission signal, etc., the control station starts wireless communication. Communication with other stations will not be lost. Further, when the communication via the transmission line becomes possible, the wireless communication is stopped, so that the wireless communication, which is inferior in reliability of information transmission to the transmission line, is not maintained. Therefore, if communication via a transmission line becomes impossible or difficult, it is possible to temporarily substitute wireless communication for maintaining communication between each station during the restoration work of the communication via the transmission line.

Therefore, if the supervisory control device of the present invention is adopted, the transmission system is not interrupted even if a transmission line disconnection accident occurs, and the reliability of the transmission system can be improved. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a supervisory control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional monitoring control device.

[Explanation of symbols]

1 transmission line 3 wireless device (wireless communication means, transmission control means) 4 transceiver unit (level determination means) M ₁ central station (control station) T _{1 to} T ₃ terminal station (control station)

Claims (1)

[Claims] 1. A supervisory control device in which a plurality of control stations that monitor and control equipment are communicating via transmission lines provided in two systems for transmission and reception, respectively. , A wireless communication means capable of always receiving wirelessly, and a level for judging whether or not the reception level of a reference signal transmitted from a specific control station through the transmission line at a constant cycle is lower than a predetermined value. When the reception level of the reference signal is lower than the predetermined value by the determination means and the level determination means, the wireless communication means permits the transmission, while the level determination means determines that the reception level of the reference signal is equal to or higher than the predetermined value. A supervisory control device comprising: a transmission control unit that prohibits transmission by the wireless communication unit when it is determined that there is.