JP3411414B2 - Data communication system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication system such as a telemeter system, and more particularly to a data communication system such as a telemeter system, which is used for occasional meter reading from a center side device including a host computer via a no ringing communication network.

[0002]

2. Description of the Related Art Conventionally, there are two types of communication methods of a telemeter system for meter reading of gas or water. One is that a terminal device such as a meter calls and activates a terminal network control unit (T-NCU). At a predetermined meter reading date and time, the T-NCU connects to the communication network, It is a method of data communication. In this case, since the terminal calls are concentrated on a specific meter reading day, there is a problem that the center network control unit (C-NCU) cannot receive the data from the T-NCU, but the call is made at the date and time when the data is collected. An automatic meter-reading system that reduces the load on the communication line by separating the date and time is disclosed in Japanese Patent Application Laid-Open No. Hei 5-130247
No. 290124).

On the other hand, there is a method of activating from the center side and performing meter reading by no ringing communication, which is called meter reading at any time. In the case of this no-ringing communication, FIG.
As shown in the timing chart of No. 1, when a ringing signal is first transmitted from the center side, the no-ringing trunk causes a gradual polarity reversal called diagonal reversal, and the no-ringing signal (PB signal) is superimposed and sent. T
-Start the NCU. The T-NCU judges whether or not this no-ringing signal is its own number, and when it judges that it is its own terminal, it returns a response with "#" of the no-ringing signal to the exchange, thereby establishing the communication path. Then, data communication becomes possible.

Then, when the data communication is started, the C-NC
The first message is sent from U, the T-NCU returns the response of the first message, and thereafter, the meter reading request message, the meter reading value response message, the end message, and the end message response are sent and received alternately, and the line is disconnected. . In addition, as a general flow of a telegram in the case of this meter reading, Japanese Patent Application Laid-Open No. 3-133242 (Japanese Patent Application 1-27137)
No. 9), it is shown in FIG. 7, FIG. 8 and FIG.

[0005]

However, the number of T-NCUs currently supported by one center has reached tens of thousands. For example, C-NCU is a meter reading day (2
4 hours), if the number of T-NCUs to be read from time to time is 10,000,
The time required for meter reading per T-NCU is 8.
It will be 64 seconds.

However, in practice, it takes 14 seconds or more if the meter reading is normally performed as shown in FIG. Regarding this content, first, after the judgment of the no-ringing signal, the no-ringing signal continues for about 1 second (T1). After the resting period (T2) of 0.6 seconds has passed since the no-ringing signal was cut off, the T-NC
A "#" response (T3) for 0.1 second is transmitted from U. After that, it is 2 before the first message is transmitted from C-NCU.
For the second (T4), the first message from the C-NCU includes 25 characters including the ID number as shown in FIG. 13 (200 baud JIS.
Approximately 1.2 seconds (T5) in 7), 0.5 seconds (T6) before the response, 0.5 seconds (T7) in response, the second message from the C-NCU (meter reading request message). Is sent for 2 seconds (T8), the request message from the C-NCU is about 0.6 seconds (T9), and the response is for 0.5 seconds (T8).
10), the meter reading telegram that collects data from the meter and transmits to the center side is 1 second (T11), and the second telegram from the C-NCU (end telegram) is 2 seconds (T12), C-
The termination message from the NCU is 0.5 seconds (T13), the response is 0.5 seconds (T14), and the response is 0.5 seconds (T13).
15), and the line is disconnected after 0.5 second (T16).

As described above, the communication time per T-NCU is about twice as long, and the T-NC with 10,000 centers is required.
Two C-NCUs are required to read U in one day. However, the price of one C-NCU is T
-It is expensive as many as several hundred times as much as NCU, and the usage fee of the no-ringing trunk, which requires one line for each C-NCU, is doubled, resulting in an increase in cost as a data communication system. was there.

As disclosed in Japanese Patent Laid-Open No. 5-130247, data is collected at a preset date and time and data is transmitted to the center at another date and time.
Although the number of NCUs is small and the load on the line can be reduced, it takes several days to finish all data communication, the total communication time does not change, and the confirmation of data on the center side is delayed, It has a drawback that the data notification to the user (billing, etc.) is delayed.

In view of the above, it is an object of the present invention to provide a data communication system capable of shortening the communication time and reducing the cost.

[0010]

The problem solving means according to the present invention is, as shown in FIG. 1, a terminal side device 6 and a center side device to which a plurality of terminal devices 7 and 8 are connected using telephone lines L1 and L2. Data is transmitted to and from No. 2 by no ringing communication. Data is collected from the terminal devices 7 and 8 before the first message is sent from the center side, and when the first message is a special message, it is collected. Only data is transmitted. Then, data collection is performed at a set date and time, or when a no-ringing signal is received as shown in FIG.

Further, the special message is formed by one character, and when the special message is received, the communication is ended at a predetermined timing.

In order to prevent communication interference and the like, a code indicating the scheduled date and time for the next data transmission is attached to the special message.

[0013]

In the above problem solving means, when the set date and time is reached or a no ringing signal is received, a meter reading request is issued to the terminal equipment 7, 8 and the terminal equipment 7, 8 is sent.
Collect data from. After that, when the first message is sent from the center side, it is determined whether the first message is a normal message or a special message. At this time, if the first message is a normal message, a normal message is exchanged,
Communication ends.

On the other hand, if the first message is a special message formed of one character, only the collected data is transmitted to the center side. Then, when the data transmission ends, the communication ends at a predetermined timing. Therefore, data communication can be performed in a shorter time than usual.

Further, by adding a code indicating the scheduled date and time for the next data transmission to the special message, the data transmission is performed when the first message from the center side arrives at the scheduled date and time, and the data is transmitted except the date and time. Do not transmit. Therefore, it is possible to prevent the intrusion of other electronic messages such as communication interference.

[0016]

【Example】

(First Embodiment) As shown in FIG. 2, the data communication system in the present embodiment uses the telephone lines L1 and L2 to perform data transmission between the terminal side and the center side by the no ringing method. And a center device 1 and a center network control unit (C-NCU) 2
, A switching center 3 connected to the center side, a switching center 4 connected to the terminal side, a no ringing trunk 5 used in no ringing communication, and a terminal network controller (T-NC).
U) 6 and L, which is a terminal device connected to the T-NCU6
It is composed of a gas meter 7 for P gas and the like and a water meter 8. In the figure, 9 is an interoffice relay line, 10, 11
Is an interface line between the terminal side switching center 4 and the no ringing trunk 5, and 12, 13 and 14 are connection lines.

As shown in FIG. 3, the T-NCU 6 includes a control unit 20 including a microcomputer, a modem unit 21 for transmitting / receiving data to / from the center, and a station communicating with the telephone lines L1 and L2 and transmitting data during communication. A meter I for controlling the input / output of the line section 22, the meters 7, 8 and the control section 20.
The / O unit 23 and the oscillator 24 that controls the operation timing of each unit. And the central office 22 is the telephone line L
It has a function of detecting the polarity reversal of 1 and L2.

As shown in FIG. 4, the control unit 20 uses a memory 25 for storing data, a program memory 26, a CPU 27 that reads a control program from the program memory 26 and controls each unit, and an oscillating unit 24. Timer counter 28 for counting the current date and time, CPU 27 and T
-I / O 29 for inputting / outputting with each unit in NCU 6.

In this data communication system, when a calling signal is transmitted from the center side, the T-NCU 6 can be activated through the no ringing trunk 5 and the meters 7 and 8 can be read. The center device 1 is C-NCU2.
Has a function of controlling the ringing communication to perform no ringing communication. During the no ringing communication, C-NCU2 to TN
A first electronic message indicating that communication is possible is transmitted to CU6. The first electronic message includes a normal electronic message formed of 25 characters including an ID number and a command as shown in FIG. 13, and a special electronic message. The special electronic message is, for example, as shown in FIG. It is made up of one letter. It should be noted that these messages are sent with marks and spaces before and after they are sent.

The control unit 20 of the T-NCU 6 has
A function of collecting data from the meters 7 and 8 at a set date and time and storing it in the data memory 25, a function of determining whether the first message from the center side is a normal message or a special message, and its determination Based on the result, when the first message is a normal message, the normal meter reading processing function that performs data transmission at normal timing as shown in FIG. 12, and when the first message is a special message, only the collected data is transmitted. It has a speed meter processing function that terminates communication at a predetermined timing (0.5 seconds after data transmission). The date and time when the no-ringing communication is performed is predetermined by the center side, and the date and time when the meters 7 and 8 read the meter is set to the date and time before the no-ringing communication is performed. In addition, meters 7, 8
The center side can arbitrarily set and change the meter reading date and time.

Next, the data transmission operation by the no ringing communication will be described with reference to FIGS. 1 and 6. First, T
In the control unit 20 of the NCU 6, the date and time is measured by the timer counter 28 (step 1), and the current date and time is compared with the set meter reading date and time (step 2). When the current date and time and the collection date and time match, both meters 7,
A meter reading request is issued to the meter 8, the data from both the meters 7 and 8 is sucked up, regular meter reading is performed, and the data is stored in the meter reading value storage area of the data memory 25 of the controller 20 (step 3). After that, a standby state waiting for a no-ringing signal from the center side is entered (step 4), and the stored data is held in the data memory 25 until the first message is sent from the center side.

Then, a calling signal is transmitted from the C-NCU 2 to the T-NCU 6 in order to perform the no ringing communication. Then, as shown in FIG.
Similarly to the operation from T1 to T4 of No. 2, the no ringing signal is judged (step 5), and after the no ringing signal is interrupted for 1 second (step 6, T21), a rest period of 0.6 second (T22), 0 After the "#" response (step 7, T23) for 1 second, the communication path is set and data communication becomes possible, and two seconds later (T24), the first message is sent from the center side.

When the control unit 20 of the T-NCU 6 receives the transmitted first electronic message (step 8, T25), it determines whether this first electronic message is a normal electronic message or a special electronic message. If the first telegram is a special telegram for 0.3 seconds as shown in FIG. 5, the speed meter reading process is started (step 9), and the waiting time of 0.5 seconds after receiving the first telegram (T2
After 6), the data of both meters 7 and 8 held in the data memory 25 is transmitted to the center side in 1 second (T
27). Then, 0.5 seconds after the data transmission is completed (T28), the line is disconnected and the communication is completed.

On the other hand, if the first message is a normal message, a normal meter reading process is performed (step 10). In this case, as shown in FIG. 12 described in the section of the related art, the electronic message is exchanged from T5 to T16, and the communication ends. Note that FIG.
In the data transmission of T11 in 2, the data stored in the data memory 25 is sent.

As described above, the data from both meters 7 and 8 are collected at the preset date and stored in the control unit 20 of the T-NCU 6, and the first electronic message sent from the center side at the time of no ringing communication is collected. By judging and transmitting only the data collected when the first message is a special message,
Data can be transmitted in a short time without exchanging messages as in the case of normal messages.

Further, since the special telegram is formed by one character, the transmission time of the telegram is 0.3 seconds, which can save 0.9 seconds as compared with the normal telegram. Moreover, since only the data is transmitted after the special message is received, and the communication is terminated after 0.5 seconds, T7 to T1 at the time of the communication by the normal message.
It is possible to save 3.6 seconds of 1 and 3.5 seconds of T12 to T15, and the communication time becomes shorter than in the past.

Therefore, since the time from the arrival of the no-ringing signal to the end of the data transmission is reduced from 14 seconds to 6 seconds, the communication time is reduced by more than half, the telephone bill is saved, the communication cost is reduced, and the economy for the user is reduced. Does not impose a physical burden. In addition, T that can manage one C-NCU2
-Expensive C-NC that can increase the number of NCU6
Since the number of U2 and the usage fee of the no-ringing trunk 5 can be reduced, it is possible to realize a substantial reduction in the initial cost of equipment of the system and the running cost of the system.

By the way, in the above embodiment, data was collected from both meters 7 and 8 at the set meter reading date and time, and both data were transmitted to the center side when the first telegram was received. Since meter reading times may differ depending on the connected meters 7 and 8, it is necessary to individually perform data transmission. Therefore, in order to perform the speed meter reading process, it is necessary to specify the data to be transmitted from the center side, and the specifying operation is troublesome.

Therefore, one character of the special message has a meaning as shown in FIG. For example, in the case of "F", the data of all meters 7 and 8 are transmitted. L for "P"
P gas data, in the case of "W", water data, and so on, after making arrangements for each terminal device in the same manner, and for the T-NCU 6 to transmit data according to the contents of this character, each meter 7, 8 data can be individually metered for speed reading, and smoother and more efficient ringing communication can be performed.

(Second Embodiment) In the data communication system of the present embodiment, the data from the meters 7 and 8 is collected when the no-ringing signal arrives and stored in the data memory 25 of the control unit 20 of the T-NCU 6. It is configured. The other structure is the same as that of the first embodiment.

In this case, data is collected and transmitted to the center side after the no-ringing communication is started. The data transmission operation will be described below with reference to FIGS. First,
The T-NCU 6 is in the standby state of the no-ringing signal from the center side, and when the calling signal is transmitted from the C-NCU 2, the standby state of the T-NCU 6 is released due to the antipole of the no-ringing trunk 5 (step 11). . After that, when the T-NCU 6 detects the no-ringing signal and confirms that it is the own terminal, the T-NCU 6 loses the no-ringing signal (step 12, T31) and then 0.6
After a quiescent period (T32) of 2 seconds, a response is returned to the terminal-side switching center 4 with a no ringing signal "#" (step 13, T33), and waits for 2 seconds until the first message is sent from the center side. (T34).

During this time, the T-NCU 6 issues a meter reading request to both meters 7 and 8 in parallel (step 14),
The data from both the meters 7 and 8 is sucked up to perform regular meter reading (step 15), the data is stored in the meter reading storage area of the data memory 25 of the controller 20, and the data collection is completed.

Then, when the first message from the center side is received (step 16, T35), it is judged whether the first message is a normal message or a special message, and if the first message is a special message, the speed is reduced. Enter the meter reading process (Step 1
7) After a waiting time (T36) of 0.5 seconds, the data held in the data memory 25 is transmitted to the center side in 1 second (T37), and 0.5 seconds later (T3).
8) The line is disconnected and the communication ends. On the other hand, if the first message is a normal message, a normal meter-reading process is performed (step 18).

In this way, by receiving the special telegram, the speed meter reading processing of the meters 7 and 8 can be performed, and the same effect as the first embodiment can be obtained. Moreover, since the data of the meters 7 and 8 are collected when the no ringing signal is received,
It is possible to omit a control operation such as data collection at a set date and time as in the first embodiment, and it is possible to continuously perform data collection to data transmission in a short time. Therefore, without increasing the number of C-NCU2, it is possible to perform meter reading at any time on one day (24 hours) of meter reading, which can contribute to cost reduction of the system.

By the way, also in this case, it is necessary to previously specify the meters 7 and 8 for data transmission.
Once specified, the speed meter reading process other than the specified meter cannot be performed until it is changed, so that a troublesome operation such as changing the specification is required. Therefore, as shown in FIG. 10, one character of a special telegram has the meaning of designating the meters 7 and 8 for performing the next speed meter reading process. For example, in the case of "F", leave the current meter reading as it is,
In the case of "P", the next time is LP gas, in the case of "W", the next time is water supply.
When the data transmission of this time is completed, the meters 7 and 8 for performing the next data transmission are stored, so that it is not necessary to specify the meters 7 and 8 to perform the meter reading in advance. , 8 can be subjected to speed meter reading processing.

(Third Embodiment) In the first and second embodiments described above, a special message is formed by one character and data is transmitted by giving meaning to this one character. In this case, since the ID number and the like included in the ordinary electronic message are omitted, there is a risk of allowing a hacker or the like that interferes with the communication to enter, resulting in a problem that data communication cannot be performed. Therefore, in the data communication system of the present embodiment, as shown in FIG. 11, a special message is provided with a code indicating the scheduled date and time for the next data transmission. The other configurations are similar to those of the first or second embodiment.

This special message is formed of a plurality of characters such as 3 or 4 characters. For example, as shown in FIG. 11, when the first character is "D", two digits are shown below. Then, this is the scheduled date and time for the next no-ringing communication. The T-NCU 6 stores this number in the data memory 2
5 is stored in the counter storage area, and this counter is decremented by the timer counter 28 of the control unit 20 from the time when this data communication ends, and a special message from the center side is sent at the date and time when this counter becomes zero. When it receives a call, data transmission is performed. The speed meter reading process is not performed even if a special telegram from the center side arrives other than the date and time when this counter becomes zero, that is, other than the scheduled date and time. However, if the first message from the center side is a normal message, an incoming call is received and the normal meter reading process is performed.

A special message is, for example, "D10
By combining four characters like "P",
The next no-ringing communication may be scheduled 10 days later, and the meter for the next meter reading may be LP gas ”.

By thus designating the scheduled date and time for performing the speed meter reading process, the probability that a hacker or the like will be allowed to enter is significantly reduced, reliable data communication can be performed, and system reliability is not deteriorated. .

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention. For example, in the above-described embodiment, when the data transmission in the speed meter reading process is completed, the line is disconnected and the communication is terminated after 0.5 seconds. However, the line state is detected and the communication is normally completed by the change. The determination may be made and the communication may be terminated. That is, if a signal indicating the end of communication is added to the data to be transmitted and the data is transmitted, the terminal side switching center 4 restores the polarity inversion of the line at the same time as the end of the data transmission. And T
-If the NCU 6 detects this polarity reversal and terminates the communication, it is determined that the communication is normally completed without the exchange of a telegram, and the communication time does not become long.

[0041]

As is apparent from the above description, according to the present invention, the first message sent from the center side during the no-ringing communication is collected when the data from the terminal device is set or when the no-ringing signal is received. By transmitting only the data collected when a special message is transmitted, data can be transmitted in a short time without exchanging messages as in the case of a normal message.

Furthermore, since the special message is formed by one character, the transmission time of the message is shorter than that of a normal message, and only the data is transmitted after the special message is received.
Since the communication ends at a predetermined timing, the communication time becomes shorter than the conventional communication time.

Therefore, the communication time from the arrival of the no-ringing signal to the end of the data transmission is shortened, the telephone bill is saved, the communication cost is reduced, and the user is not economically burdened. Also, the number of terminal side devices that can be managed by one center side device can be increased,
Since it is possible to reduce the number of expensive center-side devices, it is possible to significantly reduce the initial facility cost of the system and the running cost of the system.

Further, by designating the scheduled date and time for the next data transmission by a special electronic message, the probability that a hacker or the like will invade is reduced and communication interference can be prevented, so that reliable data communication can be performed and the system The reliability of can be improved.

[Brief description of drawings]

FIG. 1 is a flowchart showing a data transmission operation by no ringing communication in a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a data communication system.

FIG. 3 is a block diagram of a terminal network control device.

FIG. 4 is a block diagram of a control unit.

FIG. 5 is a diagram showing the structure of a special message.

FIG. 6 is a timing chart during no ringing communication.

FIG. 7 is a diagram showing the contents of one character of a special message.

FIG. 8 is a flowchart showing a data transmission operation by no ringing communication of the second embodiment.

FIG. 9 is a timing chart of the same.

FIG. 10 is a diagram showing the contents of one character of a special message.

FIG. 11 is a diagram showing the contents of characters of a special message in the third embodiment.

FIG. 12 is a timing chart during conventional non-ringing communication.

FIG. 13 is a diagram showing a structure of a normal electronic message.

[Explanation of symbols] 2 C-NCU 6 T-NCU 7,8 meters L1, L2 telephone line

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04M 11/00-11/10 H04Q 9/00

Claims (5)

(57) [Claims] 1. In a data communication system for performing data transmission by no ringing communication between a terminal side device to which a plurality of terminal devices are connected using a telephone line and a center side device, the terminal side device is from the center side. The data of the terminal device is collected before the first message is sent, and the first message specifies the data of the terminal device to be transmitted to the center side.
A data communication system, which transmits the collected data in the case of a special electronic message including characters . 2. The data collection is performed at a set date and time before the no-ringing communication is performed, or when the no-ringing communication is started and a no-ringing signal transmitted before the first telegram is received. The data communication system according to claim 1. 3. The data communication system according to claim 1, wherein the special electronic message is formed by one character. 4. The data communication system according to claim 1, wherein the communication is terminated at a predetermined timing when a special message is received. 5. The data communication system according to claim 1, wherein a code indicating the scheduled date and time for the next data transmission is added to the special message.