JPH06266292A - Information board monitoring device - Google Patents

Abstract

PURPOSE:To transmit power failure information economically to a monitoring device by installing a power failure compensation power supply for supplying power for a predetermined time to a DTMF transmitter transmitting DTMF signal to transmission line at the time of power failure on a road information board. CONSTITUTION:When the stop of a power supply to a road information board 1 is detected, signal transmission from a modulation and demodulation device 21 on the road information board 1 is stopped and a specified DTMF signal is transmitted to transmission line 3 from a DTMF signal generator 24 transmitting two-frequency AC voltages in high and low frequency regions simultaneously in the voice band. On the other hand, in a monitoring device 4 the power failure in a road information board 1 is detected on the basis of a detection signal in a DTMF signal detector 15. Then in the DTNIF signal generator 24 in the road information board, a power Failure compensation power supply 25 is provided for continuously transmitting a tone signal for the duration of from the time of power failure in the road information board 1 to the detection of the power failure in the DTMF signal detector 15 in the monitoring device 4, so that the power failure in the road information board 1 is remotely monitored. Accordingly, there is no need for use of a storage battery to compensate for the power Failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information board monitoring device for controlling and monitoring a road information board from a distance.

[0002]

2. Description of the Related Art Conventionally, a road information board is provided on a highway or on a road, the traffic condition or road condition of the preceding road is displayed on the road information board, and the driver of a passing vehicle is notified.
Preventing disasters is being done

FIG. 6 shows an example thereof, and the road information board 1 is L
Display dots are formed by using EDs or small light bulbs as display elements, the display dots are arranged in a matrix in the vertical and horizontal directions, and the power source 2 is supplied from the electric power company, and the display dots are turned on by dot-spelling to obtain desired characters or patterns. Is displayed and information is provided to the driver of the passing vehicle 8. These display contents are controlled so that the display dots are turned on and off for each display dot by data transmission from the monitoring device 4 via the transmission line 3.

The monitoring device 4 receives the emergency call from the emergency call device 6 in the tunnel 5 via the signal line 7 and controls the road information board 1 via the transmission line 3 to optimize the road information board 1. I'm trying to display. The display purpose of the road information board 1 is as follows.
It is intended to provide extremely important information for the safety of a driver of a passing vehicle, such as a symbol 10 "Caution while driving in tunnel" and a symbol 11 "Prohibition of accident occurrence and entry in tunnel".

By the way, if an important event such as a fire occurs on the preceding road, if the road information board 1 is not displayed, there is a danger that the following vehicle 8 may be involved in a disaster. From this, in order to confirm that the information is surely displayed on the road information board 1, the data for each display dot indicating the display state of the road information board 1 from the road information board 1 to the monitoring device 4 and the device Through the transmission line 3, the data indicating the state of failure, abnormality, etc. is also used as monitoring data.
It is sent by data transmission and monitored by the monitoring device 4.

When the data transmission from the road information board 1 to the monitoring device 4 is interrupted, the monitoring device 4 cannot confirm whether the display on the road information board 1 is reliable, so that the cause of the data transmission interruption is Immediate investigation and recovery are necessary.

[0007] The factors causing the data transmission to be interrupted include the case where the transmission line 3 is disconnected and the case where the supply of the power source 2 from the electric power company to the road information board 1 is stopped, that is, the case of power failure. In the former case, it is necessary to request the telephone station that manages the transmission line 3 and in the latter case to the electric power company to restore the data. However, because the classification cannot be done, immediate maintenance is required if data transmission is interrupted. It was necessary for personnel to carry out on-site surveys, and due to lack of manpower, it was difficult to elucidate the cause when the distance between the road information board 1 and the monitoring device 4 was long, or when it occurred at midnight.

[0008] Therefore, a "power failure" indicating that the supply of the power source 2 from the power company to the monitoring device 4 from the road information board 1 has stopped
It is important to distinguish the cause by transmitting a signal. As a method of transmitting the "blackout" signal, there is a method of adding the "blackout" signal to the monitoring data sent from the road information board 1 to the monitoring device 4 via the transmission line 3 by data transmission. Regarding this method, as data transmission between the road information board 1 and the monitoring device 4, control data for designating lighting and extinction of each display dot of the road information board 1 and monitoring of a lighting state of each display dot are used. Monitoring data is required.
Because of this, a huge amount of data will be transmitted,
In order to transmit such a huge amount of data in a short time without error, the HDLC transmission procedure is used as a transmission method, and a high-speed transmission of about 2400 bit / s is required for the transmission rate. Has been.

[0009]

However, a CPU is usually used for these transmission control, display control, creation of monitoring data, etc., which is large and complicated, and when combined with a modulator / demodulator, its power supply capacity becomes large. . Also,
Remodeling to preferentially transmit a power failure signal in the HDLC transmission procedure requires a great deal of remodeling. In addition, after the power supply 2 to the road information board 1 is stopped, Since a "power failure" signal is added to the monitoring data for data transmission, a power failure-compensated power supply is required for the entire device for data transmission. The power failure compensating power supply that supplies power to these devices even during a power failure becomes large, and it is necessary to provide a storage battery for power failure compensation and a charger for the storage battery, which is very expensive.

In addition, the storage battery has a lifespan, 3 to 5 years for a lead-sealed battery and 4 to 7 years for a nickel-cadmium battery (
It was necessary to replace the battery (according to the materials of the Battery Industry Association), and maintenance cost was high. In addition, a DC voltage is superimposed on the transmission line 3 that is transmitting data from the road information board 1 to the monitoring device 4, so that the road information board 1 can be used when the power failure occurs.
There is a method of inverting the polarity of the DC voltage output from the.

This method has a problem that the DC voltage does not reach the monitoring device 4 because the transmission line 3 passes through a microwave line when passing between telephone stations, and the transmission line is transmitted even within the same telephone station. In order to superimpose the DC voltage on 3, it is necessary to modify the hybrid transformer for interfacing with the transmission line provided in the modulation / demodulation device such as the road information board 1 and the monitoring device 4 by using a large DC withstand voltage / current component. There is a problem that it cannot be stored in the device.

Further, the road information board 1 has a transmission line 3 after a power failure.
Since a DC voltage with the polarity reversed is output, a DC power supply with power outage compensation is required, the power supply becomes as high as 48V, and the current value also needs to be about 20mA, and its output power is about 960mW. There is a problem that it becomes large and requires a storage battery for power failure compensation, which is expensive and complicated.

There is also a method of superimposing an AC signal in a certain voice band from the road information board on the transmission line 3 which is transmitting data from the road information board 1 to the monitoring device 4 at the time of power failure. A bandpass filter for detecting the AC signal of the power failure signal by distinguishing it from the AC signal for data transmission is required on the monitoring device side, and the characteristic of this bandpass filter is that the main region of the transmission line 3 is 0.3 to 3 .4K
Since it is as narrow as Hz, the receiver side distinguishes two AC signals within this band region, so an extremely narrow band filter is required, which makes the device large and very expensive.

[0014]

In order to solve the above problems, the present invention provides a road information board with data transmission / reception to / from a monitoring device through a transmission line for controlling and monitoring between the road information board and the monitoring device. In addition to the modulation / demodulation device for performing the operation, a DTMF transmitter for simultaneously transmitting two high-frequency and low-frequency AC voltages in the voice band is provided, and the monitoring device is provided with data of a road information board. A DTMF receiver is provided in addition to the modulation / demodulation device for transmitting and receiving.

When the stop of the power supplied to the road information board is detected, the signal transmission from the modulator / demodulator of the road information board is stopped and a predetermined DTMF signal is sent from the DTMF transmitter to the transmission line. The sending and monitoring device is configured to detect the power failure of the road information board by the detection signal of the DTMF receiver connected to the transmission line.

Further, the DTMF transmitter of the road information board,
DT of the monitoring device at least after the power failure of the road information board
By providing a power failure compensated power source that can continue to output a tone signal at a predetermined output level until the MF receiver detects a power failure, the power failure of the road information board can be monitored from a distance. It was done. Furthermore, DTMF
In the power supply device that supplies power to the receiver, a capacitor is used for power failure compensation.

[0017]

According to the present invention, since the above configuration is adopted, the road information board normally transmits a power failure signal to the monitoring apparatus at the time of power failure without modifying the data transmitting means between the road information board and the monitoring apparatus. It can be sent using a wire, and the power supply capacity of the power failure compensation power supply is small, and the power failure can be compensated by the capacitor.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the functional configuration diagram of FIG. 1, power failure compensation power supply circuit diagram of FIG. 2, time chart of FIG.
The description will be made based on the DTMF signal combination table of. In FIG. 1, the same symbols as in FIG. 6 indicate corresponding parts.

The transmission line 3 is a general leased line in the voice band,
This is what TT etc. generally offer. One of them is connected to the modulation / demodulation device 14 of the monitoring device 4 and the DTMF signal receiver 15, and the other is connected to the common contact c of the contacts 26a of the relay 26 of the road information board 1, and the make contact a of the contacts 26a is connected. The break contact b is connected to the modulator / demodulator 21, and the break contact b is connected to the output terminal of the DTMF signal transmitter 24.

The DTMF signal transmitter 24 is a power failure compensating power source 2
The power that has been compensated for blackout is being supplied from 5. The commercial power supply 27 supplied from the electric power company is a modulation / demodulation device 21, a power failure compensation power supply 25, a transmission control unit 22, a display unit 23, a relay 26.
The relay 26 operates during the supply of the commercial power supply 27, at which time the contact 26a is connected to the common c and the make contact a, and is restored at the time of a power failure to connect the common c and the break contact b.

During the supply of the commercial power supply 27, the modulation / demodulation device 21 controls the display content of the road information board 1 from the modulation / demodulation device 14 of the monitoring device 4 through the transmission line 3 and the common c of the relay contact 26a and the make contact a. Of the supplied modulation control data 19 and demodulates the demodulation control data 30 to the transmission control unit 22.
Output to. Upon receiving the demodulation control data 30, the transmission control unit 22 outputs a display command 31 to the display unit 23, and the display unit 23
When the display command 31 is received, the display command 31 corresponds to the display command 31 and, for example, displays the display characters indicated by symbols 9, 10, and 11 shown in FIG.

In this way, the display unit 23 has the symbol 9 in FIG.
In order to display arbitrary characters or patterns as shown in 10 and 11, the data sent from the monitoring device 4 to the information board 1 needs data for controlling lighting and extinction for each display dot of the display unit 23, and the data amount thereof. Will be huge. The display unit 23 also outputs a large amount of data indicating the display state and monitoring data 32 indicating the state of the device to the transmission control unit 22. The transmission control unit 22 encodes the monitoring data 32 and outputs it as the code monitoring data 33 to the modem 21.

The code monitor data 33 is modulated by the modulator / demodulator 21 and output as the modulation monitor data 41. The signal is sent to the modulator / demodulator 14 via the make contact a of the relay contact 26a, the common c and the transmission line 3. It is demodulated, and the modulation / demodulation device 14 outputs the demodulation monitoring data 34 to the transmission control unit 16.

Upon receiving the demodulation monitor data 34, the transmission control unit 16 decodes the encoded data and outputs the monitor monitor information 35 to the monitor operation unit 17, and the monitor operation unit 17 monitors when it receives the monitor monitor information 35. The display state of the road information board 1 and the state of the equipment are displayed on a monitor display device for use, such as a CRT display and a graphic panel, so that the state of the road information board 1 can be monitored from a distance.

When the display of the road information board 1 is changed, the display control data 36 is output to the transmission control unit 16 by the operation of the monitoring operation unit 17, and the transmission control unit 16 outputs the display control data 3.
6 is encoded and output to the modulation / demodulation device 14 as encoded control data 37. The modulation / demodulation device 14 uses the encoded control data 3
7 is modulated, the modulation control data 19 is output to the transmission line 3, and the display of the road information board 1 is controlled.

The DTMF signal transmitter 24 is a power failure compensating power source 2
It receives a DC power source from the AC power source 5, and simultaneously outputs two high-frequency and low-frequency AC signals within the audio band as the DTMF signal 20 to the break contact b of the relay contact 26a. Here, when the commercial power supply 27 is supplied, the DTMF signal 20 output from the DTMF signal transmitter 24 is not sent to the transmission line 3 because the contact 26a is opened, and D
The DTMF detection signal 38 is not output from the TMF signal receiver 15.

The DTMF signal is a signal normally used as a tone dialer for push-button telephones, and four types (12) of high-frequency regions within the voice band on the calling side are used.
0990Hz, 1336Hz, 1447Hz, 1633
Hz) and 4 types of low frequency range (697Hz, 770H
z, 825 Hz, 941 Hz) and each one wave is combined to make 16 kinds of combinations. Then, the AC signals that combine the two waves are transmitted at the same time, and the receiving side analyzes the AC signals that combine the two waves and detects that it is one of the 16 kinds of combinations. Can transmit the signals of 16 types, as shown in FIG.
Corresponding to the tone dial of the telephone, 1, 2, ...
It is used as 0, A, B, C, D, *, #.

Since this DTMF signal is a composite signal of two kinds of frequencies, it is a highly reliable means for signal transmission in which it is difficult to erroneously detect external noise coming on a transmission line. It is widely used as a tone dialer for button telephones. Also usually
There is no erroneous detection of the signal of the modulator / demodulator on the transmission line. Therefore, the power failure signal can be reliably transmitted.

As described above, DTMF is widely used as a tone dialer for push-button telephones.
The main functions of the signal transmitter 24 and the DTMF signal receiver 15 can be extremely easily and inexpensively configured since they can be LSI and generally commercially available.

For example, the DTMF signal transmitter 24 is a model L
B4089B (trade name, manufactured by Sharp Corporation), etc., and the DTMF signal receiver 15 is a model MSM6.
920 (trade name, manufactured by Oki Electric Co., Ltd.) and the like.

When the commercial power supply 27 supplied from the electric power company is no longer supplied, that is, when the power is cut off, the relay 26 recovers and its contact 26a is connected to the common c and the break contact b, so that the DTMF signal transmitter 24 is connected. The DTMF signal 20 output from is input to the DTMF signal receiver 15 via the common c of the relay contact 26a, the break contact b, and the transmission line 3, and the DTMF signal receiver 15 receives the DTMF signal 20 and detects DTMF. The signal 38 is output to the monitoring operation unit 17.

The monitoring operation section 17 can display and monitor that the road information board 1 is out of power by the DTMF detection signal 38. At this time, the output of the modulation / demodulation device 21 is not output because the power supply 27 is not supplied.

Since no DC voltage is superposed on the transmission line 3 in this manner, it is not necessary to modify the modulator / demodulator 14 and the modulator / demodulator 21 for data transmission between the road information board 1 and the monitoring device 4, and data is not required. Transmission control unit 2 performing transmission
The power failure of the road information board 1 can be transmitted to the monitoring device 4 with a simple configuration without modifying 2, 16, or the like.

From the power failure compensating power supply 25, the power supply is turned on even during a power failure.
Although the power is being supplied to the TMF signal transmitter 24, the time for power failure compensation is the DTM output from the DTMF signal transmitter 24.
The period until the F signal 20 is detected by the DTMF signal receiver 15 is about 10 ms, which is extremely short.

In addition to this, while the modulation / demodulation device 14 of the monitoring device 4 is outputting the modulation control signal 19, the DTMF signal receiver 15
The modulation control signal 19 and the DTMF signal 20 are simultaneously input to the DTMF signal receiver 15.
It is difficult to detect the F signal 20. From this, the power failure compensating power supply 25 needs to perform power failure compensation until the modulation / demodulation device 14 stops outputting the modulation control signal 19.

However, the time is a few seconds at the longest, and the L constituting the DTMF signal transmitter 24 is
The power consumption of SI (LR4089B (manufactured by Sharp Corp.) is as small as about 10 mw, and the DTMF signal transmitter 24
Power consumption is 100 mW even if the power consumption of the amplifier for outputting at maximum 0 dBm (1 mW) to the transmission line 3 is added.
Very few in degree.

Therefore, it is possible to use a capacitor without using a storage battery for power failure compensation. The required capacitor capacity is calculated as follows when the power failure compensation time is set to 30 seconds with a margin and the power supply voltage of the LSI (model LR4089B) and the amplifier is set to 5 volts.

FIG. 2 is a detailed diagram of the power failure compensating power supply 25.
Symbol 39 indicates a corresponding part, and symbol 39 is a DC power source, which outputs a DC voltage when receiving commercial power source 27, charges capacitor 40, and supplies the voltage to DTMF signal transmitter 24. At the time of power failure, the voltage discharged from the capacitor 40 is supplied to the DTMF signal transmitter 24,
The voltage drops in the form of CR discharge using the DTMF signal transmitter 24 as the load resistance R of the capacitor 40. DC power supply 3
If the voltage of 9 is set to 12 volts and the time to drop to 5 volts, that is, the power failure compensation time is 30 seconds, the following formula is established.

Vc = E · exp (-t / τ) Here, the respective specifications are as follows. Vc:; initial voltage across the capacitor 40 = 12V tau; voltage across = 5V E after t time of the capacitor 40 time constant = C × the resistance due to the capacitor 40 and the DTMF signal generator ^{24 (5 2 / 100mW) =} C × 250

From this, the capacity of the capacitor 40 is about 0.
Since it is 14 F, a backup capacitor for a memory, which is generally commercially available under the name of super capacitance or the like, can be used. This capacitor is also small in shape, does not need to be replaced in 3 to 7 years like a storage battery, does not require maintenance costs for regular replacement, and does not need to install a charger required for the storage battery. Since one of the ± 12 volt power supplies generally used for the interface of the modulation / demodulation device 14 can be used, the power failure compensation power supply 25 can be constructed at a low cost.

Next, the states of the respective parts of FIGS. 1 and 2 will be described with reference to the time chart of FIG. “1” and “0” indicate the state of the signal, “1” indicates yes and “0” indicates nothing.

Since the DTMF signal 20 is not output on the transmission line 3 in the section "a" where the power supply 27 is supplied, the DTMF detection signal 38 is also not output. In the section "B" where the commercial power supply 27 is not supplied, the DTMF signal 20 is output on the transmission line 3 because the output voltage of the power outage compensation power supply 25 continues to be supplied even though the output voltage decreases. As a result, the DTMF signal receiver 15 outputs the DTMF signal.
The detection signal 38 is output to the monitoring operation unit 17, and the monitoring operation unit 17 displays a power failure.

Since the DTMF signal transmitter 24 does not operate in the section "C" in which the output voltage of the power failure compensating power supply 25 has dropped to 5 volts or less, the DTMF signal 20 is not output and the DTMF signal receiver 15 outputs the DTMF signal. The detection signal 38 is also not output. However, even at that time, the monitoring operation unit 17 continues to display the power failure. Here, the section of the symbol "b" is the section for power failure compensation. When the commercial power supply 27 is restored, the modulation monitoring data 41 is output, and the section of the symbol "a", that is, the normal state is restored.

FIG. 5 shows another embodiment, in which the same symbols as those in FIGS. 1 and 2 indicate the corresponding parts, and a relay contact 26a is provided between the power failure compensating power supply 25 and the DTMF signal transmitter 24.
When 7 is supplied, since the break contact b and the common c of the relay contact 26a are opened, the DTMF signal transmitter 24 does not operate and the DTMF signal 20 is not output. Power 27
When the supply of power is stopped, the break contact b of the relay contact 18 and the common c are connected, so that the DTMF signal transmitter 2
No. 4 is operated by being supplied with power and can output the DTMF signal 20, which can be realized by changing the position of the relay contact 26a shown in FIG.

In this description, the voltage of the power failure compensating power supply 25 is normally 12 volts, and it has been described that it drops to 5 volts during a power failure. However, it is not possible to keep the power supply voltage of the LSI (model LR4089B) and the amplifier constant at 5 volts. , Constant voltage I
This can be easily done with C, Zener diode, etc.

Further, the DTMF signal 2 at the relay contact 26a.
Although it has been described by switching 0, it is needless to say that the semiconductor may be switched and the DTMF signal transmitter 24 may be transmitted by a power failure signal. Also, the transmission line 3 and the DT
Although the MF signal transmitter 24 and the DTMF signal receiver 15 are directly connected in the above description, it goes without saying that they may be connected via a hybrid transformer or the like in order to match the impedance with the transmission line 3.

In addition, the DTMF signal transmitter 24 and the DTM
As a component forming the F signal receiver 15, a model LR40 is used.
89B (commercial name) and model MSM6920 (commercial name) have been described, but the present invention is not limited to this and may be composed of other parts.

[0048]

As described above, according to the present invention, the DTMF signal transmitter, which is compensated for the power failure, is provided on the road information board and the signal is received by the monitoring device. It becomes possible to send the power failure condition of the road information board to the monitoring device without modification, and since it is sufficient to operate the DTMF transmitter for a predetermined time, the power failure compensation can be sufficiently implemented by the capacitor and the storage battery is used. Since it can be configured at low cost in combination with no need, and because it does not need to use a storage battery, its maintenance cost is unnecessary, and since it is possible to judge the failure and power failure of the transmission line depending on whether or not the DTMF signal is received, It has the effect of being able to respond quickly in the event of a failure.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing a circuit of a power failure compensation power supply.

FIG. 3 is a time chart showing an operating state.

FIG. 4 is a diagram showing a combination state of DTMF signals.

FIG. 5 is a block diagram showing the configuration of another embodiment.

FIG. 6 is a diagram showing a configuration of the entire system.

[Explanation of symbols]

 1 Road Information Board 3 Transmission Line 4 Monitoring Device 5 Tunnel 14, 21 Modulator / Demodulator 15 DTMF Detector 16, 22 Transmission Control Section 17 Monitoring Operation Section 23 Display Section 24 DTMF Transmitter 25 Power Failure Compensation Power Supply 26 Relay 40 Capacitor

Front Page Continuation (72) Inventor Takehisa Seki 1-6-2 Hatchobori, Chuo-ku, Tokyo Within Doshis Co., Ltd. (72) Inventor Toshiaki Goto 36 Terada Shinike, Joyo-shi, Kyoto Within Seiwa Electric Co., Ltd. ( 72) Inventor Moroto, Miwa-cho, Kaifu-gun, Aichi 29, Shinoda, Mt. No. 29, No. 1 at Miwa Plant, Nagoya Electric Industry Co., Ltd. (72) Mitsuru Sakai, 100 Maeda-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Within

Claims (2)

[Claims] 1. An information board monitoring device in which a road information board and a monitoring device are connected by a transmission line and the operating status of the road information board is monitored by the monitoring device, and a power failure monitoring means for detecting a stop of commercial power supply; Predetermined DTM when power failure monitoring means detects power failure
The road information board is provided with a DTMF transmitter that sends out an F signal to a transmission line, and a power failure compensation power supply that supplies power to the DTMF transmitter for a predetermined time even during a power failure, and at least the predetermined time after the power failure occurs. Is an information board monitoring device characterized by being configured to transmit power failure information to the monitoring device. 2. The information board monitoring device according to claim 1, wherein a capacitor is used for power failure compensation of the power failure compensation power source.