JPH02114756A - Automatic data communication system - Google Patents

Abstract

PURPOSE:To allow a network controller at terminal equipment side to communicate with plural terminal equipments having a different communication speed and bit length by giving a communication protocol control code in a control code sent from a center equipment to a network controller T-NCU at the terminal equipment side, decoding the code at the network controller at the terminal equipment so as to decide the communication speed and the bit length. CONSTITUTION:When a call is given from a center side equipment via a no ringing trunk 5, the arrival of a T-NCU control code is awaited and data communication is started by the same procedure as the call from the terminal. The 1st half of the communication protocol control code of the T-NCU control code includes a communication speed command space and the latter half includes a space for indicating the length of character. A T-NCU 6 measures a space length TS for indicating communication speed to discriminate the communication speed. Moreover, the space length Tb for indicating character length is measured to discriminate the length of one character. Thus, the communication with plural terminal equipments having different communication speed and bit length in the T-NCU is implemented very inexpensively.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an automatic data communication system using subscriber telephone lines.

<Prior Art> There are two types of automatic data communication systems that perform data communication 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 sensor, the terminal side network control unit (TNCU) sends a selection signal to the switching center, and the center side network control unit (TNCU) sends a selection signal to the switching center.
CU) is called and performs data communication.

In the no-ringing communication system, a no-ringing trunk is installed at the exchange that accommodates the terminal side equipment, the no-ringing trunk is called and held once from the center side equipment, and then the no-ringing trunk selects the telephone line to which the terminal side equipment is connected. reverses the polarity of the telephone line and is insensitive to house phone bells other than 16Hz ring signals.
It is designed to call a terminal device by sending out a certain alternating current signal.

These are the differences in which one links to the line first, and once the link is established and communication begins, the procedure is the same, but first, information such as which one to select from among multiple terminal devices is required. Exchange is necessary before communication, and this is called T-N
It was instructed using something called a CU control code.

There are two types of means for decoding this T-NCU control code:

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

<Problem that the invention seeks to solve> However, the former (
In the case of the first code decoding means), the communication protocol is fixed, so multiple terminal devices connected to the terminal network control device need to have the same communication speed and bit length. Terminal devices with different types will not be able to connect.

If you want to connect terminal side devices with different communication speeds and bit lengths per character, use the terminal side network control device dedicated to each communication and the no-ringing trunk 5 connected to the center side device 4 to In an automatic data communication system that connects the terminal-side network control device 6 to perform data communication without ringing the telephone 9, marks and A communication protocol control code consisting of spaces is inserted, and this communication protocol control code is decoded by the terminal side network control device 6 to determine the communication speed and bit length.

Here, the terminal side network control device 6 includes communication speed instruction space length measuring means for measuring the length of the communication speed instruction space of the communication protocol control code, and the measurement results from the measuring means are stored in advance. communication speed decoding means for determining the communication speed from speed reference data, character-length instruction space length measuring means for measuring the length of the character-length instruction space, and measurement results from the measuring means. and character length decoding means for determining the character length from the character length reference data stored in advance.

A network control device is required, and providing dedicated terminal-side and center-side network control devices for each is extremely disadvantageous in terms of both cost and maintenance.

In the case of the latter (second code decoding means), it is necessary to detect slight differences in start bit length in order to determine the communication speed and character format, which is difficult to do with a low-speed main controller. be. If we tried to realize this, it would be extremely expensive. Moreover, since the character format only takes into consideration the BELL specification, there is a problem in that only 9 or 10 bits can be identified, resulting in a lack of versatility.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention aims to provide an automatic data communication system that enables low-cost communication with a plurality of terminal devices having different communication speeds and bit lengths using one terminal-side network control device. shall be.

<Means for Solving the Problem> As shown in FIGS. 1 to 6, the means for solving the problem according to the present invention is to perform data communication by making a terminal call from the terminal side device 7.8, or to make a telephone call. Exchange of stations = 4 <Operation> In the above problem solving means, when starting data communication, the terminal side network control device 6 uses the communication in the T-NCU control code sent from the center side network control device 2. The first half space length Ts and the second half space length Tb of the protocol control code are measured to obtain the length of l characters at the communication speed.

Therefore, it is possible to communicate with terminal side devices 7 and 8 using different communication protocols using one extremely inexpensive terminal side network control device 6, and it is possible to install terminal side and center side network control devices dedicated to each communication protocol. This is extremely advantageous from both a cost and maintenance perspective compared to the case where the system was installed.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 7.

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

As shown in the figure, the automatic data communication system according to the present invention performs data communication by making terminal calls from terminal side devices 7 and 8, or by using a no-ringing trunk 5 connected to a central office exchange 4. Data communication is performed by connecting the terminal-side network control device 6 without ringing the telephone 9, and the T-NGO control code sent from the center-side device to the terminal-side network control device 6 consists of marks and spaces. The terminal side network control device 6 decodes this communication protocol control code to determine the communication speed and pit length.

As shown in FIG. 3, the terminal-side network control device 6 is a communication
・Space length for communication speed instruction to measure the length of the space for communication speed instruction in the control code. Also, Figure 5 shows the T-
A detailed block diagram of the CNU 6 is shown, and in the figure, 601
is a 16Hz call signal detection circuit, 602 is a rectifier circuit,
603 is an off-hook control circuit, 604 is a line coupling circuit,
605 is a main control device, 606 and 607 are interface circuits, 608 is a reset circuit, 609 is a transmission circuit, 6
10 is a power supply circuit, 611 is an off-hook detection circuit, 612
613 is a connection switching circuit, and 613 is a modem.

FIG. 3 is an internal configuration diagram of the main control device 605 in T-NCtJB, which controls the CPU 702 which is the central control unit, the timer counter 701 which measures the signal of the transmitting circuit 609, and the CI) U 702. The main controller 605 includes a program memory 704 that issues commands, a data memory 703 that temporarily stores internally generated data, etc.
and an interface (Ilo) 705 with the outside.

Next, the T-NCU control code will be explained.

Figure 2 shows the configuration of the T-NCU control code, which includes a communication protocol control code, a message control code measuring means,
communication speed decoding means for determining the communication speed from the measurement result from the measuring means and pre-stored speed reference data; and a character length instruction space length for measuring the length of the character length instruction space. A measurement means, a measurement result from the measurement means, and a pre-stored character.
Character length decoding means for determining character length from the 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 (r, s) connected to the terminal side. 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), and 7 and 8 are terminal-side devices with different communication protocols, including meters, sensors, and the like. 9 is the home phone, 1O1
11 is a connection line, l2. +3 is a telephone circuit line, 14 is an interoffice trunk line, and 15.16 is an interface line between the exchange 4 and the no-ringing trunk 5.

It consists of two parts.

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

The message control code is a message of the communication protocol determined by the communication protocol control code, and is a message of the communication protocol determined by the communication protocol control code.
It has information necessary for communications such as reading and writing data to, commanding telephone line connection control, and selecting the terminal device 7.8.

The communication protocol control code is composed of a relatively long mark M and a space 5, and the space length is:
This T-NCU 6 is configured to be longer than the communication protocol that has the longest space component. For example, as shown in Tables I and 2, if 200 baud and JIS 8 units (start bit + 8 bits → - parity - 10 pits) are the slowest and longest character, then the 00 code has a space component of 50m5ec, so it is set to be 55mec or more.

Table 1 Table 2 After exchanging information necessary for communication, such as the communication protocol and the port of the terminal device 7 or 8 to be communicated, the C-NCU 2 uses the T-NCU 6 as an intermediary. , communication begins between the terminal devices 7 or 8.

Next, when a call is made from the center side device, when the 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 connects the telephone 9 to the subscriber phone number. It is disconnected from the circuit line 13, waits for the T-NCU control code to arrive from the C-NCU 2, and data communication is started in the same procedure as the terminal call origination.

Here, 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, so the T-NCU 6 Space length T for speed indication
s is measured, and the communication speed is determined from the measurement result and pre-stored speed reference data (Table 1).

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 sent to 'r-NC.
When the main control device 605 receives the signal via the interface circuit 606 or 607 of U6 and the off-hook detection circuit 611 detects that the telephone 8 is not off-hook, the main control circuit 605 is disconnected from the telephone line 13 by the connection switching circuit 612. . After that, if the selection signal is a dial pulse, the off-hook control circuit 603 is turned on.
"OFF" and the signal is passed through the rectifier circuit 602, and when the selection signal is the FB double signal, the main controller 605 and the PB transmitting/receiving circuit 6.
04, a selection signal for selecting the CNCU 2 is sent to the telephone circuit line 13 via the off-hook control circuit 603 and the rectification circuit 602, respectively. When a line link is established with this selection signal, it is connected to the center side device. T-NC
Data communication is started between U6 and the center side device via the modem 613 in an asynchronous manner.

At this time, the first signal sent out is the T-NCU control code. This T-NCU control course 2Tb is measured, and the length of one character is determined from the measurement result and pre-stored character length reference data (Table 2).

In this way, the communication protocol control code is decoded by the TNCU 6 and the communication speed and bit length are determined.
- It is possible to communicate with a plurality of terminal devices having different communication speeds and bit lengths at a very low cost using - T-NCUs without installing the NCU 6.

In addition, the space lengths Ts and T of the communication protocol control code are
b is configured to be longer than the one with the longest space component of the communication protocol supported by this T-NCU 6, so the T-NCU control code is mistakenly transmitted to the terminal side device 7.b.
8, a character error will occur in the terminal device 7.8, making it possible to prevent erroneous communication.

In addition, the length is sufficient to allow even the low-speed main control device 605 to discriminate.

Next, this measuring method will be explained with reference to the flowchart of FIG. First, after confirming that the length of the first mark is longer than the specified length (step ■), the process waits for the end of the mark (step ■). Then, from the point at which 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 ■). When the mark is reached, the timer counter 701 is stopped, the count value is stored in the data memory 703, and is set as Ts (step 2).

Thereafter, Tb is measured in the same manner (steps ① to ②). From the space lengths Ts and Tb obtained in this way, the TS/communication speed recorded in advance on the program memory 704,
Obtain the communication speed and the length of one character according to the Tb/character length comparison tables-1 and 2 (step @)).

Using this communication protocol, the next message control code is deciphered, and after obtaining the necessary information, communication begins.

The main point of communication is that first, a downlink message is received from the NCU2. A communication protocol control code consisting of marks and spaces is inserted into the terminal, and the terminal-side network control device decodes this communication protocol control code to determine the communication speed and bit length. Communication with a plurality of terminal devices having different communication speeds and bit lengths can be performed at a very low cost using - terminal side network control devices without installing a side network control device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the system configuration showing an embodiment of the automatic data communication system according to the present invention, and FIG.
3 is a functional block diagram of the main control device of the terminal side network control unit (T-NCU), and FIG. 4 is a flowchart showing the procedure for determining the communication protocol control code. FIG. 5 is a detailed block diagram of the terminal-side network control device, and FIG. 6 is a detailed block diagram of the main control device of the terminal-side network control device. 1 host computer, 2; center side network control device (
C-N CU), 3. Center side switching center (LS). The terminal device 7 decodes this downlink message and returns a response message. T-NCU6 is interface 606 or 6
07, and read the response message via modem 613.
- Send to NCU2. By repeating these steps, C-N
Communication is possible between the CU 2 and the terminal device 7 or 8 using the communication protocol I/col of the terminal device 7 or 8. After this, communication continues using this communication protocol until a new control code arrives. It should be noted that 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 clear from the above description, the present invention enables data communication to be performed by making a terminal call from a terminal-side device, or by using a no-ringing trunk connected to a telephone exchange at a telephone office. In an automatic data communication system that connects a terminal side network control device and performs data communication without ringing, the T- signal sent from the center side device to the terminal side network control device.
NCU control 6 4: Terminal side switching center (LS), 5. No-ringing trunk, 6 terminal side network control unit (T-NCU), 7.8 terminal side device, 9; home telephone, 601: 16 Hz ringing signal detection circuit, 602: rectifier 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, 61
1: 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 (Ilo). Applicant Sharp Corporation NTT Kansai Telecommunications Co., Ltd.

Claims (1)

[Claims] Data communication is performed by making a terminal call from the terminal side device, or data communication is performed by connecting the terminal side network control device without making the home telephone ring using a no-ringing trunk connected to the central office exchange. In the automatic data communication system, a communication protocol control code consisting of marks and spaces is included in the T-NCU control code sent from the center side device to the terminal side network control device, and this communication protocol control code is used for terminal side network control. An automatic data communication method characterized by decoding with a device to determine communication speed and bit length.