JPH0816232A - Remote supervisory and control system - Google Patents

Abstract

PURPOSE:To transmit specific data at a short period through a communication line in a state of transmitting plural data in a prescribed period through the same communication line. CONSTITUTION:In a system connecting a control station 2 to a supervisory and control station 3 through a communication line 4, a specific data collecting means for collecting specific data DS out of plural data D at a short period TS shorter than a normal period T0 at the time of receiving a specific control command CS from the station 3 and a DTMF modulator 23 for modulating the specific data DS collected at the short period TS to a DTMF signal, superposing the DTMF signal to data D being transmitted through the line 4 and transmitting the superposed signal to the station 3 are added to the station 2. A DTMF demodulator 24 for demodulating the DTMF signal received through the line 4 into the original specific data DS is added to the station 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distant supervisory control system for supervising and controlling a control station disposed in the vicinity of an object to be controlled by a supervisory control station disposed distantly through a communication line.

[0002]

2. Description of the Related Art For example, when managing a large number of water and sewage facilities in a centralized manner, each water and sewage facility is not centrally located in one place but is distributed over a wide area, so In many cases, a centralized control center provided in the center of Tokyo controls the above state.

In this case, the control station installed in the vicinity of the controlled object such as each water supply and sewerage facility and the supervisory control station installed in the management center are connected by a communication line including a general public telephone line or a dedicated line, for example. To do. Then, the control station controls the controlled object so that the target operation state designated by the control command from the supervisory control station is reached. Further, the control station collects a large number of data indicating the operating state of the controlled object at a prescribed cycle T ₀ and transmits it to the monitoring control station.

The supervisory control station monitors each data received in a prescribed cycle and, if necessary, sends various control commands to the control station to change the target operating state of the controlled object. FIG. 5 is a schematic configuration diagram of a remote monitoring control system having the above-described functions.

A control station 2 for directly controlling the controlled object 1 is disposed near the controlled object 1 such as a water supply and sewerage facility.
The control station 2 is connected via a communication line 4 to a supervisory control station 3 arranged at a distant place.

In the control station 2, the process control device 5
Performs a predetermined control calculation such as PID calculation on the data indicating the operating state (process data) input from the control target 1, and applies the calculation result to the control target 1 as operation data. The operating state of the controlled object 1 is controlled to the target operating state.

Further, the process control device 5 collects data D ₁ , D ₂ , D ₃ , ... Indicating the operating state of the controlled object 1 at a predetermined prescribed period T ₀ and sends it to the next modulator 6. Send out. The modulator 6 sends the digital data to the oscillator 6a.
The carrier wave signal f _{CL of} , for example, 2400 Hz, which is output from, is modulated and transmitted as a data signal to the communication line 4 via the high pass filter 7 and the hybrid circuit 8.

The data signal input to the supervisory control station 3 via the communication line 4 is input to the demodulator 11 via the hybrid circuit 9 and the high pass filter 10. Demodulator 11
Uses this data signal as the original digital data D ₁ , D ₂ ,
The data is demodulated into D ₃ , ... And sent to the monitoring controller 12.

The monitoring control device 12 is composed of a kind of computer, and stores data D ₁ , D ₂ , D ₃ , ... Representing the operating state of the controlled object 1 received at a prescribed cycle T ₀ in sequence C.
Time is displayed on the RT display device 13 as a trend graph with the horizontal axis representing time. Also, each received data D ₁ , D ₂ , D
_{When an} abnormal value is detected in ₃ , ...

The observer who grasps the abnormality inputs, via the keyboard 14, for example, appropriate control commands C ₁ , C ₂ , ... For avoiding the abnormal state. Further, even when the normal operation condition change is instructed instead of the abnormality occurrence, the control commands C ₁ , C ₂ , ... Are input from the keyboard 14. Further, the monitor control device 12 itself may automatically output appropriate control commands C ₁ , C ₂ , ... In accordance with a preset operation program.

The control commands C ₁ , C ₂ , ... Output from the monitor controller 12 are input to the modulator 6. The modulator 15 modulates the digital control commands C ₁ , C ₂ , ... With a carrier wave signal f _{CH of} , for example, 2800 Hz output from the oscillator 15 a, and sends the control signal to the communication line 4 via the high pass filter 10 and the hybrid circuit 9. As.

The control signal input to the control station 2 via the communication line 4 is a hybrid circuit 8 and a high pass filter 7.
Is input to the demodulator 16 via. The demodulator 16 demodulates this control signal into the original digital control commands C ₁ , C ₂ , ... And sends it to the process controller 5.

The process control device 5 changes the target operating state according to the control commands C ₁ , C ₂ , ... Received from the supervisory control station 3. Then, the process control device 5 controls the control target 1 so that the operating state becomes the target operating state after the change.

Further, in such a remote monitoring control system, telephones 17 and 18 are provided for exchanging information between supervisors stationed at the control station 2 and the supervisory control station 3, respectively. There is. The voice signals output from the telephones 17 and 18 are the communication interface 1 respectively.
It is input to the hybrid circuits 8 and 9 via 9 and 20 and the low pass filters 21 and 22.

The hybrid circuit 8 of the control station 2 is a modulator 6
The data signal output from the telephone and the voice signal output from the telephone 17 are signal-synthesized and sent to the communication line 4. Further, the hybrid circuit 9 of the supervisory control station 3 synthesizes the control signal output from the modulator 11 and the voice signal output from the telephone 18 and sends the signal to the communication line 4. Therefore, the data signal, the control signal, and the voice signal are superimposed on the communication line 4. Since each of these signals has a different frequency band to be used, it can be correctly reproduced by interposing a filter or the like. In this way, by effectively using the communication line 4, the supervisory control station 3 to the control station 2
It is possible to control remotely and efficiently.

[0016]

However, the remote monitoring and control system as shown in FIG. 5 still has the following problems to be solved. That is, a plurality of data D ₁ , D ₂ , D ₃ , ..., D _N. indicating the operating state of the controlled object 1 are _sent as data signals from the control station 2 to the supervisory control station 3 at every predetermined cycle T _0. Sent to.

In recent years, the number of data N transmitted from the control station 2 to the supervisory control station 3 is increased in order to make the controlled subject 1 complicated and to remotely control the operation of the controlled subject 1 accurately from the supervisory control station 3. Tend to do. Since the usable frequency band of the communication line 4 represented by a telephone line has a certain limit, the data transmission rate on the communication line 4 is limited. As a result, the specified period T ₀ is extended in order to increase the number N of transmission data. As a result, the transmission cycle of each data D _{1 to} D _N becomes long.

On the other hand, for example, when an abnormality occurs in the controlled object 1 and an emergency control command is input from the supervisory control station 3 or a control command for greatly changing the operating condition is input,
Is it necessary to closely monitor, for example, the specific data D _S directly related to the control command among the _N data D _{1 to} D _N indicating the operating state of the controlled object 1 in response to the specific operation command C _S ? is there.

However, since all the data D _{1 to} D _N are uniformly transmitted at the above-mentioned specified period T ₀ interval, immediately after the control command of the specific data D _S directly related to the specific control command C _S is transmitted. There was a problem that the detailed value in could not be grasped.

The present invention has been made in view of such circumstances, and in addition to data signals and control signals, D
By superimposing a TMF signal, specific data can be converted into a DTMF signal according to a specific control command and transmitted, and in the state where each data is transmitted at a normal prescribed cycle, the specific data is further shortened. It is an object of the present invention to provide a distant monitoring control system that can be transmitted by the above-mentioned method and can significantly improve the monitoring control accuracy of a control target of a control monitoring station via a control station.

[0021]

In order to solve the above-mentioned problems, the present invention controls a controlled object to a target operating state based on a control command input from the outside, and a plurality of operating states of this controlled object. The control station that collects and outputs the data in a specified cycle and each data output from the control station is received through the communication line, the data is monitored, and the communication line is sent to the control station based on the data value. In a distant monitoring control system including a monitoring control station that sends a control command via a control command, when a specific control command is received from the monitoring control station Specific data collecting means for collecting in a short short period, and specific data collected in this short period are modulated into a DTMF signal, superposed on each data being transmitted on the communication line, and transmitted to the supervisory control station. It is added and the MF modulator. Further, a DTMF demodulator for demodulating the DTMF signal received through the communication line into the original specific data is added to the supervisory control station.

[0022]

In the distant party surveillance control system configured as described above, in the normal state, the control station controls the controlled object to the target operating state based on the control command received from the supervisory control station, and indicates the operating state. Multiple data is sent to the supervisory control station at specified intervals.

Then, when a specific control command is received from the supervisory control station, specific data of the plurality of data is converted into a DTMF signal in a short cycle shorter than a prescribed cycle and sent to the supervisory control station via the same communication line. Sent.

DTMF (Dual Tone Multiple Frequency)
A multi-frequency code) signal is transmitted through a telephone line as is well known.
It is a signal used when transmitting numbers up to 9 and some symbols such as #, and is composed of two high and low frequency signals f _H and f _L as shown in FIG. That is, as shown in the frequency distribution characteristic of FIG. 2, since the DTMF signal has two peaks at two distinct specific frequency positions, even if the DTMF signal is superposed on the data signal, it can be easily separated. Can be demodulated.

Therefore, by converting the specific data into the DTMF signal and transmitting it to the communication line, even if the data signal is being output on the communication line, it is completely independent of the data signal and at an arbitrary timing. This specific data can be transmitted to the supervisory control station. Therefore, the specific data can be transmitted to the supervisory control station in a short cycle shorter than the normal specified cycle.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a remote monitoring control system according to an embodiment. The same parts as those of the conventional remote monitoring control system shown in FIG. 5 are designated by the same reference numerals. Therefore, detailed description of the overlapping portions is omitted.

In the remote monitoring and control system of this embodiment, a DTMF modulator 23 is provided in the control station 2. This DTMF modulator 23 outputs a binary digital specific data D _S of [1] or [0] output from the process controller 5a to a DT composed of two frequency signals f _H and f _L.
It is converted into the MF signal a and sent to the hybrid circuit 8.

In the supervisory control station 3, D received from the control station 2 via the communication line 4 and the hybrid circuit 9 is received.
DTM which demodulates the TMF signal a into the original binary data D _S of [1] or [0] and sends it to the monitor controller 12a.
An F demodulator 24 is provided.

[0029] Incidentally, when transmitted by superimposing the DTMF signal a normal audio signal, since the DTMF signal a the telephone network exchange is likely to mistaken call destination telephone number, a specific data D _S When converting to the DTMF signal a, a code such as [#] indicating that it is not the telephone number of the called party is added to the beginning.

The process controller 5a of the control station 2 controls the operating state of the controlled object 1 to the target operating state. This target operating state is given by control commands C ₁ , C _2, ... Included in the control signal e received from the supervisory control station 3 via the telephone line 4. Further, the process control device 5a, the data D ₁ showing an operating state of the controlled object 1 at a specified period _{T 0, D 2, D 3} ,
, D _N are collected and sent to the next modulator 6. The modulator 6 modulates each of the data D _{1 to} D _N with the carrier signal f _CL (= 2400 Hz) output from the oscillator 6 a and sends it as a data signal b to the communication line 4 via the high pass filter 7 and the hybrid circuit 8. To do. The high-pass filter 7
Prevents the low-fractional audio signal c from entering the demodulator 16.

The data signal b input to the supervisory control station 3 via the communication line 4 is input to the demodulator 11 via the hybrid circuit 9 and the high pass filter 10. Demodulator 1
1 represents the original data D ₁ , D ₂ , D ₃ ,
_,, and demodulates to D _N and sends it to the monitor control device 12a.

The supervisory controller 12a uses the data D ₁ and the data D ₁ that indicate the operating state of the controlled object 1 that is sequentially received at the specified cycle T ₀ .
D ₂ , D ₃ , ..., D _N are graphically displayed on the CRT display device 13. Further, when an abnormal value is detected in each of the received data, an alarm is output to an observer that an abnormality has occurred.

The monitoring controller 12a also controls the control command C ₁ . C ₂ . Is transmitted to the modulator 15. The modulator 15 uses this control command C ₁ . C
₂ ． Is the carrier wave signal f output from the oscillator 15a.
_{The signal} is modulated with _cH (= 2800 Hz) and sent as a control signal e to the communication line 4 through the high pass filter 10 and the hybrid circuit 9.

The control signal e input to the control station 2 via the communication line 4 is input to the demodulator 16 via the hybrid circuit 8 and the high pass filter 7. The demodulator 16 sends this control signal e to the original control command C ₁ . C ₂ . It is demodulated to ... And sent to the process control device 5a.

The process control device 5a receives the control command C ₁ . C ₂ . Change the target operation state according to. Then, the process control device 5 controls the control target 1 so that the operating state becomes the target operating state after the change.

Further, the process control device 5a receives the received control command C ₁ . C ₂ . When the specific control command C _S designated in advance is included in ..., The short period T _S shorter than the specified period T ₀ by a predetermined period T _M from the reception time.
Sequentially collect specific data D _S corresponding to this particular control command C _S from the control target 1 in. It should be noted that this specific data D _S is a plurality of data D _{1 to} D _N collected at a prescribed cycle T ₀
It is specified from among. The process control device 5a uses the DTMF modulator 2 to output the specific data D _S sequentially collected in the short cycle T _S.
Send to 3.

Therefore, the specific data D _S has a short cycle T _S.
Are sequentially transmitted to the supervisory control station 3 via the communication line 4.
as a result. The supervisory control device 12a of the supervisory control station 3 can receive this specific data D _S at short cycle T _S intervals.

Further, the supervisors stationed at the supervisory control station 3 and the supervisory station 2, respectively, can use the telephones 18.17 installed in their own stations 3 and 2 to make a call. In this case, the audio signal c is each signal a, which is being transmitted on the communication line 4,
It is superimposed on b and d.

FIG. 2 is a frequency characteristic diagram showing the use frequency range of the data signal b, the control signal d, the DTMF signal a and the voice signal c transmitted on the communication line 4. The carrier frequency f _CH (= 2800Hz) of the control signal d is set near the upper limit frequency of use of one communication line 4, and the carrier frequency f _CL (= 2400Hz) of the data signal b is set near the lower side. .
The frequency band of the audio signal c is set to the filters 21, 22.
For example, it is set to 1800 Hz or less. Also,
[1] or the pair showing a [0] frequency signal f _H, F _L
Is set.

Then, each of these signals a, b, c, d,
e is a high-pass filter 7, 10, a low-pass filter 21,
22 or a band-pass filter (not shown) or the like, even if they are superposed on the communication line 4, each of the original data D _{1 to} D _N , the control command C ₁ . C ₂ . It is possible to restore to the specific data D _S.

FIG. 4 is a time chart showing respective signals a to d transmitted and received through the communication line 4 between the control station 2 and the supervisory control station 3 of the remote supervisory control system of the embodiment. Note that, in FIG. 4, the signals a to c are described independently, but on the communication line 4, these four signals a to d are transmitted in a state of being superimposed on each other.

From the control station 2 to the supervisory control station 3 the specified cycle T ₀
N data D ₁ and D indicating the operating state of the controlled object 1
_The data signal b including ₂ , D ₃ , ..., D _N is repeatedly transmitted. On the other hand, if necessary, the supervisory control station 3 sends a control command C ₁ . C ₂ . The control sum signal e including ... Is transmitted. Further, the voice signal c for conversation between the monitoring personnel is transmitted / received between the monitoring control station 3 and the control station 2 irrespective of the specified period T ₀ .

Then, at time t ₁ , the control signal e including the specific control command C _S from the supervisory controller 3 is sent to the control station 2.
Then, the control station 2 starts collecting the specific data D _S corresponding to the specific control command C _S in the short cycle T _S. Each specific data D _S is repeatedly transmitted to the supervisory control station 3 as the DTMF signal a every short period T _S.

When the control station 2 stops the collection at time t ₂ after the elapse of a predetermined period T _M , the transmission of the specific data D _S of the short cycle T _S to the monitoring control station 3 is stopped, and Only the data D _{1 to} D _{N are} transmitted according to the specified cycle T ₀ .

In the distant supervisory control system thus configured, in the normal state, the control station 2 sets the control target 1 to the target operating state based on the control commands C ₁ , C ₂ , ... Received from the supervisory control station 3. controls the plurality of data D _1, D ₂ showing an operating state, ..., defines a D _N periods T
_{When it is 0} , it is transmitted to the supervisory control station 3.

Then, for example, when a specific control command C _S is sent from the supervisory control station 3 to the control station 2 immediately after an abnormality has occurred in the controlled object 1 or the operating conditions have been changed, this specific control command C _S On the other hand, the specific data D determined in advance
_S is collected in a short cycle T _S shorter than the specified cycle T ₀ and automatically transmitted to the supervisory control station 3.

Therefore, the supervisory control station 3 can grasp the detailed transient response phenomenon of the specific data D _S relating to the occurrence of the abnormality or the change in the operating conditions in the controlled object 1 immediately after the occurrence of the abnormality or the change in the operating conditions.

Therefore, it is possible to use the existing communication line without providing a dedicated communication line for transmitting specific data separately, and to take prompt action in the event of an abnormality and to provide more detailed information when necessary. Data can be collected, the reliability of the remote monitoring control system can be improved, and the monitoring control accuracy can be greatly improved.

The present invention is not limited to the above-described embodiment system. In the system of the embodiment, the telephones 17 and 18 are arranged in the control station 2 and the supervisory control station 3, respectively. However, for example, the control station 2 is close to the controlled object 1 that is operating unmanned, such as the water collection facility of a dam in the mountains. When arranged, the control station 2 may not have an observer stationed there.
In such an unmanned system, telephones 17, 1
No need to install 8.

Further, in the embodiment system, the case where one control station 1 and one supervisory control station 3 are provided has been described. For example, it may be a system in which there is one monitoring control device 3 and a plurality of control stations 2.

In this case, since the specified period T ₀ for transmitting each data D _{1 to} D _N from each control station 2 to the supervisory control station 3 is extended by the number of times the control station 2 is installed, the specific data D _S is assigned to the DTM.
The technical effect of converting to the F signal a and transmitting to the monitoring control station 3 in the short cycle T _S becomes more remarkable.

[0052]

As described above, in the remote monitoring and control system of the present invention, the DPMF signal is superimposed on the data signal and the control signal on the communication line. Therefore, the control station can convert specific data into a DPMF signal according to a specific control command from the monitoring control station and transmit the DPMF signal to the monitoring control station via the communication line.

As a result, it is possible to transmit specific data in a short cycle through the same communication line while each data is being transmitted in a normal prescribed cycle using one communication line.
It is possible to significantly improve the monitoring control accuracy of the control target of the monitoring control station via the control station.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a remote monitoring control system according to an embodiment of the present invention.

FIG. 2 is a frequency characteristic diagram of each signal transmitted through a communication line in the system of the embodiment.

FIG. 3 is a diagram showing a combination of frequencies in respective frequency signals forming a general DTMF signal.

FIG. 4 is a time chart showing each signal transmitted through a communication line in the system of the embodiment.

FIG. 5 is a block diagram showing a schematic configuration of a conventional remote monitoring control system.

[Explanation of symbols]

1 ... Control object, 2 ... Control station, 3 ... Supervisory control station, 4 ... Communication line, 5, 5a ... Process control device, 6, 15 ... Modulator, 7, 10 ... High pass filter, 8, 9 ... Hybrid circuit, 11, 16 ... Demodulator, 12, 12a ... Supervisory control device, 13 ... CRT display device, 14 ... Keyboard, 1
7, 18 ... Telephone, 19, 20 ... Call interface,
21, 22 ... Low-pass filter, 23 ... DTMF modulator, 24 ... DTMF demodulator

Claims (1)

[Claims] 1. A control station that controls a controlled object to a target operating state based on a control command input from the outside, and collects and outputs a plurality of data indicating the operating state of this controlled object in a prescribed cycle, A monitoring control station that receives each data output from the control station via a communication line, monitors each data, and sends a control command to the control station based on the data value via the communication line. In the distant monitoring control system, the control station, when receiving a specific control command from the monitoring control station, collects specific data of the plurality of data in a short cycle shorter than the specified cycle. And a DTMF modulator that modulates specific data collected in this short cycle into a DTMF signal, superimposes it on each of the data being transmitted on the communication line, and transmits the data to the supervisory control station. A, the monitoring control station, received via the communication line DT
A remote supervisory control system having a DTMF demodulator for demodulating an MF signal into original specific data.