JPH06205471A - Time division multiplex data transmission system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a time division multiplexing data transmission system with a simple transmission control configuration. A time-division signal transmission device 4 for periodically transmitting time-division signals to a transmission line on a transmission line 3, a time-division signal reception means 11, a request command transmission means 12, a terminal response command reception means 13 on a central device 1, and Central response command transmitting means 14, time division signal receiving means 21 in the terminal control device 2,
It comprises request command receiving means 22, terminal response command transmitting means 23, and central response command receiving means 24. [Effects] Various conventional techniques such as complexity of recovery procedure from a transmission disabled state, limitation of characters that can be present in transmission data due to transmission control characters, or necessity of constant monitoring of transmission control characters by a terminal control device. You can solve the problem.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for performing time division multiplex data transmission between a central device and a plurality of terminal control devices. For example, the central device is a computer and a network is provided via a transmission line. By connecting a production machine (numerical control machine tool, etc.) to each configured terminal control device,
A time division multiplex data transmission method capable of transmitting time division multiplex data between a computer and a production machine

[0002]

2. Description of the Related Art Conventionally, as a data transmission method for transmitting and receiving control data between a computer (central device) which is a main control device and control devices (terminal control devices) of a plurality of production machines connected as controlled devices, Therefore, a time division multiplex data transmission method based on the so-called polling access method is known. However, the data transmission method by the polling access method has the following problems. (1) The central device and the terminal control device are provided with several kinds of timer functions for recovering the transmission control after a set time in case the transmission control becomes impossible due to some reason during data transmission. In addition, the central unit may be equipped with a timer function that optimizes the polling interval in order to prevent meaningless overload due to frequent repeated polling access even though there is no data transmission / reception. Was needed. Moreover, it is necessary to adjust the timer functions so that the set values of the timers are not inconsistent between the central device and the terminal control device. In the conventional technology, there is a drawback that setting of timers and adjustment between timers are complicated and difficult, and a procedure for recovering from a transmission disabled state becomes complicated. (2) When the transmission control character is used for transmission control, a character having the same bit pattern as that of the transmission control character cannot exist in the transmission data, so that the data that can be transmitted is limited. In order to solve this, the code independent mode of "basic data transmission control procedure", the transparent mode of "BSC", and "H
Although there is a method of using a high-class transmission control procedure such as "DLC", there is a drawback that the transmission control becomes complicated. (3) When the transmission control character is used for the transmission control, the terminal control device can always respond to the transmission control character sent from the central device so that the character is always transmitted during data transmission between other terminal control devices. It was necessary to constantly monitor the transmission control character.
In particular, when the terminal control device is controlled by the central processing unit (CPU), the CPU is occupied by the multiplex transmission control, and there is a drawback that other controls cannot be substantially performed. In order to solve this, there is a method of using a high-grade transmission control procedure such as "HDLC", but there is a drawback that the transmission control becomes complicated.

[0003]

As described above, according to the conventional data transmission method, it is difficult to set and adjust the timers in the central unit and the terminal control unit, the handling thereof is difficult, and the transmission is impossible. There are various problems, such as the complexity of the recovery procedure, the limitation of characters that can exist in the transmission data due to the transmission control character, and the constant monitoring of the transmission control character in the terminal control device. The object of the present invention is made in view of the above problems, eliminates the need to install a timer function in the central device and the terminal control device, and simplifies the procedure for recovering from a transmission-disabled state. An object of the present invention is to provide a time-division multiplex transmission method of simple transmission control by eliminating the character limitation of transmission data and relieving the terminal control device from constant monitoring of transmission control characters.

[0004]

In order to achieve the above object, the invention of claim 1 of the present invention provides a data transmission network in which a central unit and a plurality of terminal control units are connected to a multipoint via transmission lines. In a time division multiplex data transmission system for transmitting data between the central device and each terminal control device, when a time division signal which is a pulse signal is periodically sent to a transmission line to the network. A division signal transmission device is installed, and the central device is provided with time division signal reception means, request command transmission means, terminal response command reception means and central response command transmission means,
The terminal control device comprises time division signal receiving means, request command receiving means, terminal response command transmitting means, and central response command receiving means, and the central device is
A request command including an address of a terminal control device which gives a transmission / reception right each time the request command transmission means receives the time division signal from the time division signal transmission device by the time division signal reception means and the request command transmission means receives the time division signal. In addition to sending to the transmission line, the terminal response command receiving means receives the response command of the terminal control device, and the central response command transmitting means causes the terminal control device to respond to the reception of the response command of the terminal control device. The terminal control device receives the time-division signal from the time-division signal transmission device by the time-division signal reception device, while the request command reception device performs the transmission sequence for transmitting the response command. The received character string immediately after receiving the divided signal is recognized as a request command and the terminal response One block of data to which transmission control information is added or transmission control information is transmitted to the central unit as a response to which the command transmitting unit gives the transmission / reception right, and the central response command receiving unit transmits the central response command transmitting unit from the central response command transmitting unit. The central device executes the transmission sequence for receiving the transmitted response command, and after receiving the response from the terminal control device to which the transmission / reception right is given, the central device transmits the data of the block to which the transmission control information is added or the transmission control information. It is characterized in that the transmission sequence is transmitted to the terminal control device to which a transmission / reception right is given, and the transmission sequence between the central device and the terminal control device is completed within the divided time divided by the time division signal. Further, in the invention of claim 2 of the present invention, in the above-mentioned claim 1, when transmission is performed in an asynchronous manner, a time division signal is transmitted by one transmission character (including a start bit, a duty bit, a stop bit) or more. The break signal is a low-level pulse signal having a width of. Furthermore, the invention of claim 3 of the present invention is the above-mentioned claim 1, wherein the time-division signal transmitting device is the time for transmitting the time-division signal while the central device is transmitting data. The transmission of the time division signal is stopped until the end of the data transmission of the central device. The invention according to claim 4 of the present invention is characterized in that, in claim 1, the central device includes the time division signal transmission device.

According to the present invention having the above-mentioned configuration, the schematic configuration diagram of FIG. 1 and the timing diagram of FIG. 2 (D, F, B _{1 to} B _{6 in the} figure)
(Corresponding to the signals of the same reference numerals in FIG. 1)), one central unit 1 and a plurality of terminal control units 2 ₁
.. 2 ₆ .. 2 _n .. are connected to the multipoint by the transmission line 3, and time division multiplexed data transmission is performed between the central device 1 and each terminal control device 2 ₁ to 2 _n. ) A time division signal transmission device 4 for periodically transmitting the time division signal TDP which is one pulse signal to the transmission line 3 is provided. (2) central device 1, each time it receives the divided signals TDP time, one particular terminal control device 2 ₁ to 2 _6, · · 2 _n ·
・ Send / receive right to (B1 → B2 → B3 → B4 → B5 →
B6 → ... _Bn ...), a request command RC including the address AD of the terminal control device to which the transmission / reception right is given is sent to the transmission line 3 (request command transmission means 12). (3) For example, 2 ₁ of the terminal control devices recognizes the received character string immediately after receiving the time division signal TDP as the request command RC, and compares the address AD in the request command RC with its own address (request). Command receiving means 22). If the address AD and its own address match, as a "response", a terminal response command TACA composed of transmission control information and one block of data,
Or, a terminal response command T composed only of transmission control information
The ACB is transmitted to the central device 1 (terminal response command transmitting means 23). If the address AD and its own address do not match, the request command RC is discarded, the transmission sequence ends, and the next time division signal TDP is waited for. (4) The central device 1 is composed of transmission control information and one block of data after receiving the terminal response command TACA (or TACB) from the terminal control device to which the transmission / reception right is given (terminal response command receiving means 13). The central control command CACA for transmitting the central control command CACA or the central control command CACB consisting only of the transmission control information is given to the terminal control device 2 ₁
(Central response command transmission means 14). (5) The transmission sequence of (2) to (4) is completed within the division time DT divided by the time division signal TDP. (6) The time division signal transmission device (D) uses the time division signal TDP
When it is time to send out, the command transmitting signal F notified from the central unit 1 is inspected, and if it is not transmitting, a time division signal is sent out, and if it is transmitting, the command transmitting of the central unit 1 ends. Stop sending time division signals.

As described above, since the central device and the plurality of terminal control devices according to the present invention adopt the method of executing the transmission sequence each time the time division signal periodically transmitted to the transmission line is received, the central device and the terminal control device. The transmission control between the control devices can be easily timed, and the transmission control can be simplified. If there is no data transmission between the central unit and the terminal control unit to which the transmission / reception right is given, there is a time lag between the completion of the transmission sequence and the reception of the next time division signal. It is possible to prevent meaningless overloading of the central unit even if there is no function. Even if the transmission control cannot be completed due to some reason, the central control unit and the terminal control device to which the transmission / reception right is given have a process of interrupting the transmission sequence at the time when the next time division signal is received. Since it suffices to carry out and start a new transmission sequence, the procedure for recovering from the transmission control disabled state becomes simple, and of course, the timer function for recovering from the transmission control disabled state is not necessary. In addition, since the transmission sequence is activated by the reception of the time-division signal, the central unit and the terminal control unit can determine or judge the meaning of the character in the transmission and reception order of the character. Also, the transmission control information can be expressed, and the bit pattern does not limit the characters in the data. Further, the terminal control device does not need to receive the character until the time division signal is received, and is also released from the constant monitoring of the transmission control character.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.
Will be described in detail. FIG. 3 shows a time division multiplexed data according to the present invention.
1 is an overall block diagram illustrating an example of a data transmission system.
1, the same reference numerals as those in FIG.₁~ 5₆Is
Communication line, 6 ₁~ 6₆Is a numerically controlled machine tool. Same figure
Is a time-division signal transmission device to the central device 1 via the transmission line 3.
4 and terminal control device 2₁~ 2₆Connect to the multipoint
Each terminal control device 2₁~ 2₆Point to poi
Numerical control machine tool 6 having a communication interface
₁~ 6₆And communication line 5₁~ 5₆Are connected by
Network, and a central device 1 and a terminal control device 2₁~
Two₆Asynchronous time division multiplexing transmission between
1 and numerical control machine tool 6₁~ 6₆Data to and from each other
This is a system configuration that allows double transmission.
FIG. 4 shows an example of the configuration of the central device 1 and the time division signal transmission device 4.
In the block diagram shown, 101 is a CPU and 102 is an
Storage for operating system (OS), 103 for communication
Interface (communication IF), 104 is a multiplex transmission device
Chair driver, 105 stores multiplex transmission main program
Part, 106 is a keyboard, 107 is a monitor (CR
T), 108 is a storage medium, and 401 is a break signal generation time.
Reference numeral 402 is a transmission driver. First, time-division signaling
The output device 4 is one character called a break signal.
Set a low-level pulse signal with the above pulse width
Break signal generation times that occur periodically at specified time intervals
The route 401 and the in-transmission signal F indicate that the command of the central unit 1 is transmitted.
Break signal by opening the gate only when not showing the signal
And a transmission driver 402 for transmitting the
The break line, which is a divided signal, causes the transmission line 3 to move
To divide. The central device 1 includes a CPU 101 and an OS storage unit 1.
02, communication IF circuit 103, multiplex transmission device driver
104, multiplex transmission main program storage unit 105, key
Consists of board 106, CRT 107, and storage medium 108
Be done. The communication IF 103 receives the break signal and the character
Send and receive data and generate an interrupt signal BS.
The function to interrupt the CPU 101, the central unit 1
Whether the signal is transmitting or not being transmitted
It has a function of notifying the signal transmission device 4. Multiplex transmission control
The vice driver 104 is an interrupt signal of the communication IF 103.
Stores interrupt program started by BS
The interrupt program storage unit 1041 of each terminal control device
Address table 1042 where addresses are stored, end
Transmission data buffer 1043 for each end control device, terminal control
It is composed of a reception data buffer 1044 for each device. Communication
The signal IF 103 receives a break signal and sends a character.
The interrupt signal BS is generated by the reception and the CPU 101
Is interrupted, and the CPU 101 controls multiplex transmission.
Interrupt program storage unit 1 of device driver 104
Communication of transmission sequence with 041 interrupt program
Performed through IF103. Transmission data is for each terminal controller
From the transmission data buffer 1043 for
Received data from the terminal control device is received for each terminal control device.
It is stored in the data buffer 1044. Multiplex transmission main
The multiplex transmission main program stored in the program storage unit 105.
The program is transmitted / received by the multiplex transmission control device driver 104.
Received data buffers 1043, 1044 and storage medium 108
Data transfer to and from O stored in the OS storage unit 102.
Carry out through S. Also, the keyboard 106 is a transmission system.
Set the conditions and enter the data, and the CRT 107
Displays the transfer status of data and data. Figure 5 shows terminal control
1 is a block diagram illustrating an embodiment of an apparatus,
Is a CPU, 202 is a communication IF, and 203 is an interrupt transmission system.
A program storage unit, 204 is a main program storage
Part, 205 is an address setting part, and 206 is a transmission data buffer.
FA, 207 is a reception data buffer, 208 is a display unit,
209 is an output unit and 210 is an input unit. Terminal control device
2 is a CPU 201, a communication IF 202, a multiplex transmission control program.
Program storage unit 203, main program storage unit 20
4, address setting unit 205, transmission data buffer 20
6, reception data buffer 207, display unit 208, input unit
209 and an output unit 210. Communication IF circuit 20
2 receives a break signal and sends and receives characters
At the same time, an interrupt signal BS is generated and the CPU 201 is interrupted.
It has a function to apply a leak. Interrupt transmission control program
RAM is activated by the interrupt of communication IF202.
It is a built-in program. Communication IF 202 is a break message
Signal by receiving the signal and sending and receiving characters
BS is generated to interrupt the CPU 201.
The CPU 201 is the interrupt transmission control program storage unit 20.
With the interrupt transmission control program of 3, the transmission sequence
This is done through the communication IF 202. By multiplex transmission to the central device 1
The data to be transmitted is fetched from the transmission data buffer 206
Data received from the central unit 1 by multiplex transmission is received.
Stored in the reception data buffer 207. Main program
The main program stored in the system storage unit 204 is input
And a numerical control machine tool through the unit 210 and the output unit 209.
Input and output data between and send the input data
Receives data output to the data buffer 206 and output
It is taken out from the data buffer 207. In this example
Is the terminal control device 2 (2₁~ 2₆) And numerical control machine tool
6 (6₁~ 6₆) Communication line 5 (5₁~ 5₆) Through
Since this is an example of performing one-to-one data transmission, input / output
The parts (209, 210) become communication interfaces
However, the input / output section of the terminal control device 2 is connected to the contact input / output or A /
By using a D, D / A converter, multiple numerical values
Centralized control of machine tool status measurement and operation control from a central device
It can also be used for other purposes. FIG. 6 shows this embodiment.
It is an explanatory diagram of the format of the command in
“Command format 1” with no transmission data and transmission data
There are two types of "command format 2". Command type
Equation 1 ”consists of address, control byte and checksum.
“Command format 2” is for address, control byte, data
Data, transmission data, and checksum. Control
Send to notify that data can be received in the control byte
Notify the destination that the requested bit and data have been received.
There are known reception completion bits and the like. Dividing time of this example
(Corresponding to DT in FIG. 2) is the transmission rate of multiplex transmission.
20 msec at 150 kbps, central terminal
Device 1 and 6 terminal control devices 2₁~ 2₆One way to and from
Assuming that there is always data transmission, central device 1 and terminal control
The actual transmission speed between the devices 2 is about 19200 bps.
Communication with the outside often used for numerical control machine tools
Maximum interface transmission rate of 9600 bps
There is no decrease in transmission rate due to multiplex transmission. Then on
Detailed operation of the embodiment Function and operation of each component
This will be described with reference to the flow. FIG. 7 shows the central device of this embodiment.
Fig. 3 is a functional block diagram of the storage and time-division signal transmitter.
The central unit 1 includes the signal receiving means 15 and the signal discriminating means 1
6, address setting means 17, terminal response command receiving means
18, request command creating means 19, terminal response command
Command analysis means 20, central response command creation means 21,
And reception data buffer 22 for each terminal device and each terminal device
It comprises a transmission data buffer 23. Also, time-division signal transmission
The output device 4 is provided with the time-division signal transmission means 25 and a fixed time interval
The split signal generating means 26 is provided. Each of the above means is as shown in FIG.
It is a more specific embodiment of the general function of the present invention described in the above.
By combining the constituent parts in the description of the embodiment of FIG.
Is generated. 8 is executed by the function block shown in FIG.
5 is an operation flowchart of the central device. Below, figure
The operation of No. 7 will be described with reference to the flowchart of FIG.
The data transmission operation starts, and the signal receiving means 15 transmits.
The signal from the path 3 is received, and the received signal is time-division transmitted.
The signal discriminating means 16 determines that the signal is a time division signal from the output device 4.
When the determination is made (S-1), the address setting means 17 at this time
Sequential transmission / reception rights to the terminal control device based on the reception of divided signals
An address for giving is set (S-2). This ad
The request command creating means 19 is set according to the reply setting.
Create a request command containing the specified address
(S-3), connection from the command transmission means 24 to the transmission line 3
It transmits to the terminal control device which did (S-4). Signal receiving means
A signal is received from the transmission line 3 via S15 (S-5), and
It is discriminated as a character by the signal discriminating means 16.
(S-6), terminal response command from the terminal control device
Is completed (S-7), and is received normally (S-
8), the terminal response command analysis means 20 sends this command
After analysis (S-9), the central response command corresponding to this command
The central response command creating means 21 creates a command (S
-10), sending from the command sending means 24 to the transmission path 3
(S-11). Request command and response command
Command is being transmitted during transmission of
F is given to the time division signal transmission means 25. Also, to S-6
The received signal was determined to be a time division signal
If so, go back to S-2 and select S-6 and S-8 respectively.
If there is an error in receiving a command, an error in receiving a command, or above
When the command transmission is completed, the process returns to S-1. In addition,
FIG. 9 shows a time-division communication executed by the function block shown in FIG.
3 is an operation flowchart of the signal transmission device,
When the work starts, the timer turns on (S-21).
A time division signal is generated from the time division signal generation means 26 at a constant time interval.
To live. The time division signal transmission means 25 is the command of the central unit 1.
The presence or absence of the command transmitting signal F from the command transmitting means 24 is determined.
Disconnected (S-22), when there is no signal F during command transmission
Then, the time division signal is sent to the transmission line (S-23). Figure 10
Is a functional block diagram of the terminal control device of the present embodiment,
27 is a command transmitting means, 28 is a terminal response command creation
Means, 29 is a transmission data buffer, 30 is a signal receiver
Steps, 31 is signal discrimination means, 32 is character reception permission,
Prohibition means, 33 is address verification means, 34 is a request
Command receiving means, 35 is a central response command receiving means,
36 is a request command analysis means, and 37 is a central response command.
The command analysis means 38 is a reception data buffer. Up
Each means has the general functions of the present invention described in FIG.
In the description of the embodiment of FIG.
It is generated by combining each component. 11 and 12
Central unit operation performed by the function block shown in FIG.
It is a production flow chart. Hereinafter, the operation of FIG.
It will be described with reference to the flowchart of FIG. data
When the transmission operation starts and the signal receiving means 30 is the transmission line 3
And the received signal is a time-division signal transmission device.
The signal discriminating means 31 discriminates that the signal is a time division signal from 4
Then, the character reception is permitted (S-31) (S-
32), signal reception is executed (S-33). Received message
No. is determined to be a character signal (S-3
4) determine whether or not it is the first character (S
-35) Address collating means 3 for the first character
The address is collated in step 3 (S-36) and the match is confirmed.
Reception of quest command completed (S-37), command
If normal reception (S-38), request command analysis
The means 36 analyzes the reception request command (S-
39) A terminal response command is generated by the terminal response command creating means 28.
A code is created (S-40). Created terminal response command
Is sent to the transmission line 3 via the command sending means 27.
(S-41). Then, from the transmission line 3 in response to the above response
Receives the transmitted signal (S-42), which is the character
(S-43) reception of the central response command
Judgment (S-44) → Judgment of normal command reception (S-4
After processing 5) and the command is received normally,
The central response command is analyzed by the central response command analysis means 37.
Analyze (S-46). In S-34, the character
If a communication error occurs, the address verification fails in S-36.
If the command is not received normally in S-38, S
When a character reception error occurs at -43, and
If the command is not received normally in S-45,
Performs character reception prohibition processing (S-47), and proceeds to S-31.
Return. Furthermore, in S-34 and S-43, it is received.
If it is determined that the signal is a time division signal, return to S-32.
It By executing each sequence above,
Device, time-division signal transmitter and terminal controller
Data is multiplexed and transmitted.

As described above, according to the present invention,
A time-division signal periodically sent to the transmission line temporally divides the transmission line, and simultaneously notifies the central unit and a plurality of terminal control units of the start and end of the divided time, and the central unit and the plurality of terminals. Since the control device has a simple transmission control system that executes a transmission sequence each time it receives a time division signal that is periodically sent to a transmission line, it is effective between the central device and multiple terminal control devices. Time-division multiplex data transmission can be realized. In addition, the drawbacks of the conventional method are the complexity and difficulty of setting and adjusting the timers in the central unit and the terminal control unit, the complexity of the procedure for recovering from the untransmittable state, and the character that can be present in the transmission data by the transmission control character It is possible to solve the problems in the prior art such as the limitation or the need to constantly monitor the transmission control character in the terminal control device, and to provide a time division multiplex data transmission system having excellent functions.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a basic configuration of a time division multiplex data transmission system according to the present invention.

FIG. 2 is a timing diagram illustrating the operation of the basic configuration of the time division multiplex data transmission system according to the present invention.

FIG. 3 is an overall block diagram illustrating an embodiment of a time division multiplex data transmission system according to the present invention.

FIG. 4 is a block diagram showing a configuration example of a central device and a time division signal transmission device for explaining an embodiment of a time division multiplexing data transmission system according to the present invention.

FIG. 5 is a block diagram illustrating an embodiment of a terminal control device for explaining an embodiment of a time division multiplex data transmission system according to the present invention.

FIG. 6 is an explanatory diagram of a command format in one embodiment of the time division multiplex data transmission system according to the present invention.

FIG. 7 is a functional block diagram of a central apparatus and a time division signal transmission apparatus in an embodiment of the time division multiplex data transmission system according to the present invention.

8 is an operation flowchart of a central unit executed by the function block shown in FIG. 7 in one embodiment of the time division multiplex data transmission system according to the present invention.

9 is an operation flowchart of the time division signal transmission apparatus executed by the function block shown in FIG. 7 in one embodiment of the time division multiplex data transmission system according to the present invention.

FIG. 10 is one of time division multiplex data transmission systems according to the present invention.
It is a functional block diagram of the terminal control device in an Example.

FIG. 11 is one of time division multiplex data transmission systems according to the present invention.
FIG. 11 is a partial view of an operation flowchart of a central device executed by the function block shown in FIG. 10 in the embodiment.

FIG. 12 is a time division multiplex data transmission system 1 according to the present invention.
FIG. 11 is another partial view of the operation flowchart of the central apparatus executed by the functional block shown in FIG. 10 in the embodiment.

[Explanation of Codes] FIG. 1 1 Central device 2 ₁ to 2 _6, ..., 2 _n ... Terminal control device 3 Transmission line 4 Time division signal transmission device 11 Time division signal reception means 12 Request command transmission means 13 Terminal response command reception Means 14 Central response command transmission means 21 Time division signal reception means 22 Request command reception means 23 Terminal response command transmission means 24 Central response command reception means Fig. 2 TDP time division signal AD terminal control unit address RC request command TACA Transmission control information and Terminal response command consisting of 1 block of data TACB Terminal response command consisting of only transmission control information CACA Central response command consisting of transmission control information and 1 block of data CACB Central response consisting of transmission control information Command ST Transmission stop pulse DT minutes Time Figure 3 5 ₁ to 5 ₆ communication line ₆₁ through ₆ numerically controlled production machine diagram 4 101 CPU 102 operating system (OS) storage unit 103 communication interface (communication IF) 104 multiplex transmission device driver 105 multiplex main program storage unit 106 keyboard 107 monitor (CRT) 108 storage medium 401 break signal generation circuit 402 transmission driver FIG. 5 201 CPU 202 communication IF 203 interrupt transmission control program storage unit 204 main program storage unit 205 address setting unit 206 transmission data buffer 207 reception data buffer 208 input section diagram display unit 209 output unit 210 7 15 signal receiving means 16 signal determination unit 17 address setting means 18 terminal response command receiving unit 19 requests the command preparation unit 20 End response command analyzing means 21 central response command generating means 22 terminal by the received data buffer 23 the terminal device by transmitting data in buffer 25 time division signal transmitting unit 26 a predetermined time interval divided signal generating means 10. FIG 27 command transmitting unit 28 terminal response command Creating means 29 Transmission data buffer 30 Signal receiving means 31 Signal determining means 32 Character reception permission / inhibition means 33 Address collating means 34 Request command receiving means 35 Central response command receiving means 36 Request command analyzing means 37 Central response command analyzing means 38 Received data buffer

Claims (4)

[Claims] 1. A data transmission network in which a central unit and a plurality of terminal control units are connected to one another via transmission lines in a multipoint manner to transmit data between the central unit and each of the terminal control units. In the division multiplexing data transmission system, a time division signal transmission device for periodically transmitting a time division signal which is one pulse signal to a transmission line is installed in the network, and the central device is provided with a time division signal receiving means and a request command. A transmission unit, a terminal response command receiving unit, and a central response command transmitting unit, and the terminal control device includes a time division signal receiving unit, a request command receiving unit, a terminal response command transmitting unit, and a central response command receiving unit. The central device receives the time division signal from the time division signal transmission device by the time division signal reception means, Each time the request command transmitting means receives a time division signal, the request command including the address of the terminal control device to which the transmission / reception right is given is transmitted to the transmission line, and the terminal response command receiving means transmits the response command of the terminal control device. While executing the transmission sequence of receiving and transmitting the response command to the terminal control device in response to the reception of the response command of the terminal control device by the central response command transmitting means, the terminal control device is The signal receiving means receives the time division signal from the time division signal transmitting device, recognizes the received character string immediately after the request command receiving means receives the time division signal as a request command, and transmits the terminal response command. One block with transmission control information added as a response to which the transmission / reception right is given by the means. The central device 1 transmits lock data or transmission control information to the central unit, and the central response command receiving unit executes a transmission sequence for receiving the response command transmitted from the central response command transmitting unit of the central unit. After receiving the response from the terminal control device to which the transmission / reception right is given, transmits one block of data to which the transmission control information is added or the transmission control information to the terminal control device to which the transmission / reception right is given, and transmits the time division signal. A time division multiplex data transmission system characterized in that a transmission sequence between the central unit and the terminal control unit is completed within a divided division time. 2. The time division signal according to claim 1, wherein the time division signal is a break signal which is a low level pulse signal having a width of one transmission character or more. Division multiplexing data transmission system. 3. The time division signal transmission device according to claim 1, wherein when the time to transmit the time division signal is reached while the central device is transmitting data, the time division signal transmission device until the end of data transmission of the central device. A time division multiplex data transmission method characterized in that the transmission of time division signals is stopped. 4. The time division multiplex data transmission system according to claim 1, wherein the central unit includes the time division signal transmission unit.