JPH0683328B2 - Automatic data communication method - Google Patents

Description

The present invention relates to an automatic data communication system using a subscriber telephone line.

<Prior Art> There are two types of automatic data communication systems in which data communication is performed between a terminal-side device and a center-side device via a telephone line: a terminal calling communication system and a no ringing communication system.

In the terminal call communication system, when a call is made from a terminal-side device such as a meter or sensor, the terminal-side network control unit (T-NCU) sends a selection signal to the switching center and the center-side network control unit (T-NCU). NC
U) is called and performs data communication.

In the no-ringing communication method, a no-ringing trunk is installed in the exchange that accommodates the terminal-side device, the center-side device calls the no-ringing trunk once, and then the no-ringing trunk selects the telephone line to which the terminal-side device is connected. By reversing the polarity of the telephone rotation, the terminal side device is called by sending an AC signal that is insensitive to the bell of the home telephone other than the 16Hz calling signal.

These are the differences in which goes to the line first, and the procedure is the same when the link is established and communication starts, but first, information such as which to select among multiple terminal side devices Exchange is necessary prior to communication, and this is T-NC
I was instructed with what is called U control code.

There are the following two types of means for decoding the T-NCU control code.

First, the communication speed and bit length are determined in advance with the terminal side network control device. The second is to automatically determine the communication speed and character format using the "AT command" method.

<Problems to be Solved by the Invention> However, in the case of the former (first code decoding means), since the communication protocol is fixed, a plurality of terminal side devices connected to the terminal side network control device are It is necessary to have the same communication speed and bit length, and it becomes impossible to connect terminal devices having different ones.

When connecting terminal devices with different communication speeds and bit lengths per character, a terminal-side network control device dedicated to each communication and a center-side network control device are required. The provision of the center-side network control device was extremely disadvantageous in terms of cost and maintenance.

In the latter case (second code decoding means), it is necessary to detect a slight difference in the start bit length in order to judge the communication speed and character format, which is difficult for a low speed main controller. is there. If this were to be realized, it would be very expensive. Moreover, because the CHARACTER FOMA TUT considers only BELL specifications,
There was a problem in that only 9 or 10 bits could be identified and the versatility was poor.

Therefore, in view of the above problems, an object of the present invention is to provide an automatic data communication method capable of inexpensively performing communication with a plurality of terminal side devices having different communication speeds and bit lengths by one terminal side network control device. And

<Means for Solving Problems> As shown in FIGS. 1 to 6, the means for solving problems according to the present invention performs data communication by calling a terminal from the terminal side devices 7 and 8, or a telephone. In the automatic data communication system in which the no-ringing trunk 5 connected to the exchange 4 of the central office is used to connect the terminal side network control device 6 without ringing the home telephone 9 to perform data communication, the center side device and the terminal side network are connected. In the T-NCU control code transmitted to the terminal side network control device 6 by using the asynchronous basic procedure as the communication protocol with the control device 6, the communication speed of one bit constituting the charactor format and one charactor in the communication. A communication protocol control code indicating the length of the communication protocol is inserted, and the communication protocol control code defines a mark and a space longer than the maximum space length of the communication protocol. Formed,
The terminal side network control device 6 measures the space lengths of the communication speed instruction space and the character length instruction space of this communication protocol control code, and the communication speed and bit length are calculated from the measurement result and the prestored reference data. To decide.

<Operation> In the above problem solving means, when starting data communication, the terminal side network control device 6 controls the communication protocol in the T-NCU control code sent from the center side network control device 2. The space length Ts in the first half and the space length Tb in the second half of the code are measured to obtain the communication speed and the length of one charactor.

Therefore, one very inexpensive terminal side network control device 6 can communicate with the terminal side devices 7 and 8 having different communication protocols, and the terminal side and center side network control devices dedicated to the respective communication protocols are installed. It is very advantageous in terms of cost and maintenance as compared with the case where it is done.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram of a system configuration showing an embodiment of an automatic data communication system according to the present invention, and FIG. 2 is the same T-NC.
U control code configuration diagram, FIG. 3 is a functional block diagram of the main control unit of the terminal side network control unit (T-NCU), and FIG. 4 is a flow chart diagram showing the procedure for determining the communication protocol control code. FIG. 5 is a detailed block diagram of the terminal side network controller, and FIG. 6 is a detailed block diagram of the main controller of the terminal side network controller.

As shown in the figure, the automatic data communication system according to the present invention, whether the data communication is performed by calling a terminal from the terminal side device 7 or 8,
Alternatively, the no-ringing trunk 5 connected to the exchange 4 of the central office is used to perform data communication by connecting the terminal side network control device 6 without ringing the home telephone 9, and the center side device controls the terminal side network. A communication protocol control code composed of a mark and a space is put in the T-NCU control code transmitted to the device 6, and this communication protocol control code is decoded by the terminal side network control device 6 to determine the communication speed and bit length. To do.

As shown in FIG. 3, the terminal side network control device 6 measures a communication speed instruction space length measuring means for measuring the length of the communication speed instruction space of the communication protocol control code, and a measurement result from the measuring means. Communication speed decoding means for determining the communication speed from the speed reference data stored in advance, charactor length indicating space length measuring means for measuring the length of the space for indicating the charactor length, and the measuring means from the measuring means. A charactor length decoding means for discriminating the charactor length from the measurement result and the prestored charactor length reference data is provided.

That is, in FIG. 1, 1 is a host computer,
2 is a center side network control unit (hereinafter referred to as C-NCU), 3
Is a switching center (LS) connected to the center side, and 4 is a switching center (LS) connected to the terminal side. Reference numeral 5 is a no-ringing trunk used in the original no-ringing system. 6 is a terminal side network control unit (hereinafter referred to as T-NCU), 7, 8
Is a terminal side device having a different communication protocol, and includes a meter, a sensor and the like. 9 is a home telephone, 10 and 11 are connection lines, and 12 and 13
Is a telephone circuit line, 14 is an interoffice relay line, and 15 and 16 are interface lines between the exchange 4 and the no-ringing trunk 5.

Further, FIG. 5 is a detailed block diagram of the T-CNU6, in which 601 is a 16 Hz calling signal detection circuit, 602 is a rectifier circuit, 603 is an off-hook control circuit, 604 is a line coupling circuit, and 60 is a line coupling circuit.
5 is a main controller, 606 and 607 are interface circuits, 608
Is a reset circuit, 609 is an oscillation circuit, 610 is a power circuit, 611
Is an off-hook detection circuit, 612 is a connection switching circuit, and 613 is a modem.

FIG. 6 is an internal configuration diagram of the main control unit 605 in the T-NCU 6,
A CPU 702 that is a central control unit, a timer counter 701 that inputs and clocks a signal from a transmission circuit 609, a program memory 704 that instructs the CPU 702 to control, a data memory 703 that temporarily holds internally generated data, Interface (I / O) 70 between main controller 605 and the outside
It consists of 5 and.

Next, the T-NCU control code will be described. Figure 2 shows T
-It shows the structure of the NCU control code, and consists of two parts, a communication protocol control code and a message control code.

The communication protocol control code indicates the communication speed in the asynchronous communication and the length of one character in the communication.

The telegram control code is a telegram of the communication protocol determined by the above-mentioned communication protocol control code, and commands the reading and writing of data to the T-NCU 6, the telephone line connection control command, the selection of the terminal side devices 7, 8, and the like. It has information necessary for communication.

The communication protocol control code is composed of a combination of a relatively long mark M and space S, and the space length is
This T-NCU 6 is configured to be longer than the one having the longest space component of the communication protocol supported. For example, as shown in Table-1 and Table-2, 200 baud, JIS
If 8 units (start bit + 8 bits + parity = 10 bits) are the slowest communication speed and the longest character, the 00 code has a space component of 50 msec, so it should be 55 mec or more.

In the above configuration, in the case of terminal call communication in which a call request is issued from the terminal-side device 7 or 8, this call request is
If the off-hook detection circuit 611 detects that the telephone 8 is not off-hook by the main control unit 605 via the interface circuit 600 or 607 of the NCU 6, the main control circuit 605 causes the connection switching circuit 612 to switch the telephone line 13 Separate more. After that, when the selection signal is a dial pulse, the off-hook control circuit 603 is turned “ON” and “OFF”, and the rectifier circuit 602 is turned on.
If the selection signal is a PB signal, the main controller 60
5, through the PB transmission / reception circuit 604, the off-hook control circuit 603, and the rectifier circuit 602, selection signals for selecting the C-NCU 2 are sent to the telephone circuit line 13. When a line link is established for this selection signal, the center side device is connected. T
-Asynchronous data communication is started between the NCU 6 and the center side device via the modem 613.

At this time, the signal transmitted first is the T-NCU control code. With this T-NCU control code, after exchanging information necessary for communication such as the communication protocol and the port of the terminal side device 7 or 8 to communicate, C-NCU2 and terminal side device 7 with T-NCU6 as an intermediary. Or communication starts between 8.

Next, when a call is made from the center side device, when a call is made from the center side device via the no ringing trunk 5, the T-NCU 6 confirms that the home telephone 9 is not off-hook, and then the telephone 9 is called. After disconnecting from the circuit line 13, waiting for the T-NCU control code to arrive from the C-NCU 2, the data communication is started in the same procedure as the terminal call.

Here, since the communication protocol control code of the T-NCU control code includes a communication speed instruction space in the first half and a character length instruction space in the second half,
The T-NCU 6 measures the communication speed instruction space length Ts in the first half, and determines the communication speed from the measurement result and the speed reference data (Table-1) stored in advance.

Also, the instructing space length Tb of the latter half of the charactor length is measured, and one charactor length is discriminated from the measurement result and the prestored charactor length reference data (Table 2).

In this way, the communication protocol control code is decoded by the T-NCU 6, and the communication speed and bit length are determined.
Without installing the NCU 6, one T-NCU can very inexpensively communicate with a plurality of terminal side devices having different communication speeds and bit lengths.

The communication protocol control code space length Ts, Tb
Is configured longer than the one with the longest space component of the communication protocol supported by this T-NCU6, so even if the T-NCU control code is erroneously sent to the terminal side devices 7 and 8, the terminal side It becomes possible to prevent erroneous communication due to a character error in the devices 7 and 8.

The length is also long enough to be discriminated by the low-speed main controller 605.

Next, this measuring method will be described with reference to the flow chart of FIG. First, after confirming that the length of the first mark is not less than the specified length (step), the end of the mark is waited (step). And from the time when the mark ends,
The CPU 702 in the main controller 605 starts the timer counter 701 (step) and waits for the start of the next mark (step). If the mark comes, a timer counter
Stop 701, store the count value in the data memory 703, and set it as Ts (step). Similarly, Tb is measured (steps to). Space length Ts, T thus obtained
From b, each comparison table of Ts / communication speed and Tb / character length previously recorded in the program memory 704-1,2
Then, obtain the communication speed and the length of one charactor (step). Communication is started after decoding the following electronic message control code using this communication protocol and obtaining necessary information.

As for the communication procedure, first, the downlink message from C-NCU2 comes.
Main controller 605 reads this via modem 613 and sends it to terminal side device 7 or 8 via interface 606 or 607. The terminal device 7 decodes this downlink message,
Returns the response message. The T-NCU 6 reads the response message via the interface 606 or 607 and C via the modem 613.
-Send to NCU2. By repeating these, the terminal-side device 7 or 8 is connected between the C-NCU 2 and the terminal-side device 7 or 8.
Communication is possible with the communication protocol of the side

After that, communication is continued using this communication protocol until a new control code arrives.

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.

<Effects of the Invention> As is apparent from the above description, the present invention uses the asynchronous basic procedure as the communication protocol between the center side device and the terminal side network control device to transmit to the terminal side network control device. In the control code, a communication protocol control code indicating the communication speed of one bit forming the character format and the length of one character in the communication is inserted, and the communication protocol control code has a mark longer than the maximum space length of the communication protocol. Consists of spaces,
The terminal side network controller measures each space length of the communication speed control space and the character length control space of this communication protocol control code, and determines the communication speed and bit length from the measurement results and prestored reference data. Therefore, without installing multiple network controllers on the terminal side,
A single terminal-side network control device can very inexpensively communicate with a plurality of terminal-side devices having different communication speeds and bit lengths.

Further, since the space length of the communication protocol control code is configured to be longer than that having the longest space component of the communication protocol supported by this terminal side network control device, the T-NCU control code is erroneously transmitted to the terminal side device. Even if it is sent, a character error will occur in the terminal device, and erroneous communication can be prevented.

Moreover, since the communication speed by the asynchronous basic procedure is slower than other communication protocol procedures, the communication speed can be detected even if sampling is performed at a speed lower than the communication speed, and a low-speed and inexpensive microcomputer is used. can do.

[Brief description of drawings]

FIG. 1 is a block diagram of a system configuration showing an embodiment of an automatic data communication system according to the present invention, and FIG. 2 is the same T-NC.
FIG. 3 is a functional block diagram of the main control unit of the terminal side network control unit (T-NCU), and FIG. 4 is a flow chart diagram showing the procedure for determining the communication protocol control code. FIG. 5 is a detailed block diagram of the terminal side network controller, and FIG. 6 is a detailed block diagram of the main controller of the terminal side network controller. 1: Host computer, 2: Center side network controller (C-
NCU), 3: Center side exchange (LS), 4: Terminal side exchange (L)
S), 5: No ringing trunk, 6: Terminal side network control unit (T-NCU), 7, 8: Terminal side device, 9: Home telephone, 601: 16H
z call signal detection circuit, 602: rectification circuit, 603: off-hook control circuit, 604: line coupling circuit, 605: main control device, 606,
607: Interface circuit, 608: Reset circuit, 609: Transmission circuit, 610: Power supply circuit, 611: Off-hook detection circuit, 612:
Connection switching circuit, 613: modem, 701: timer counter, 702: central control unit (CPU), 703: data memory, 704: program memory, 705: interface (I /
O).

Claims (1)

[Claims] 1. A data communication is performed by calling a terminal from a terminal side device, or a terminal side network control device is connected without ringing a home telephone using a no ringing trunk connected to a telephone exchange. In the automatic data communication method for performing data communication by using the asynchronous bake procedure as a communication protocol between the center side device and the terminal side network control device, the character code is included in the T-NCU control code transmitted to the terminal side network control device. Forming a format 1
A communication protocol control code indicating the communication speed of the bit and the length of one character in the communication is inserted, and the communication protocol control code is composed of a mark and a space longer than the maximum space length of the communication protocol. Automatically characterized by measuring the space lengths of the communication protocol control code communication speed instruction space and the character length instruction space, and determining the communication speed and bit length from the measurement results and prestored reference data. Data communication method.