JPS62249542A - Data transfer system - Google Patents

Abstract

PURPOSE:To shorten a time required for the return of responses from all terminal equipments by executing poling simultaneously from a master station and transferring data sequentially from each data terminal equipment immediately after the end of a response of the immediately preceding data terminal equipment. CONSTITUTION:At first, the master station M transmits simultaneously a select signal to respective terminal equipments A1-AN. A transmitting/receiving interface circuit 1 receives the simultaneous select signal sent from the master station M through a data transmission line L and transmits the signal to a simultaneous select signal detecting circuit 2. Detecting the arrival of the simultaneously select signal, the circuit 2 generates a signal indicating a arrival timing and sends the signal to a self-station selectdetecting circuit 3. The circuit 3 is waited to detect the self-station select at the arrival of the simltaneous select signal and then monitors response signals returned from respective terminal equipments, and after the end of a response signal of the immediately preceding terminal equipment which has been previously set up, sends the transmission request of the self-station response data to an information tranmission control circuit 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a data transfer system, and in particular, data transfer from a plurality of terminal devices connected in a multi-drop format such as a CATV (cable television) system to a master station. This relates to the tth data transfer method for transferring .

[Conventional technology]

An example of a multi-drop type connection is shown and explained in FIG. 3. This figure is a block diagram for explaining a multi-drop type connection for both the conventional technology and the present invention. FIG. 4 is a detailed time chart explaining the conventional data transfer method.

As shown in FIG. 3, the communication system is a multi-drop type communication system in which one end is connected to a master station M and a plurality of terminal devices A or AN for transmitting and receiving data are branch-connected to the next data transmission line. It is a system.

When data is transferred from each terminal device A to AN to the master station M, conventionally, selection is performed individually for each terminal device at the timing shown in FIG. 4.

That is, in FIG. 4, first, the master station M sends a select signal in a predetermined format, which has been given to the terminal device A in advance and the terminal address is set in the address designation part (not shown), to the data transmission line. Send directly. Upon receiving this select signal, the fixed terminal device A1 sends back to the master station M response data in which its own station address is set in the address designation field and the transfer data is set in the data field. And this master station M is
After receiving the response data sent from the terminal device ffl A+, it sends a select signal addressed to the terminal device A2, and the terminal device A2, which has received this, returns the response data to the master station M.

Thereafter, the master station M transfers data to each terminal device A to AN in the same manner.

[Problem that the invention seeks to solve]

In the conventional data transfer method described above, the master station M
Since the select signal is sent sequentially to each of *, or AN, it takes a long time to send the select signal to all terminal devices A or AN, especially when there are a large number of terminal devices. As a result, communication in modes other than data transfer is often obstructed.

[Elaborate means to solve problems]

In the data transfer method of the present invention, the master station transmits a select signal to multiple terminal devices all at once, and after the transmission of the select signal is completed, a predetermined terminal device that has been designated to transmit in advance returns a response first. , after the response is completed, the second, third and subsequent terminal devices are equipped with means for returning responses in a preset order.

[For production]

In the present invention, the master station performs polling all at once, and each data transmission/reception terminal device sequentially transfers data immediately after the previous terminal device completes its response.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and shows an extracted part related to a terminal device for data transmission and reception. Connected.

In Fig. 1, the parts with the same numbers as IE3E indicate corresponding parts, and 1 receives the simultaneous select signal sent from the master station M via the data transmission line, and also sends response data to the master station M. a transmitting/receiving interface circuit for sending back signals; a simultaneous select signal detecting circuit that receives the output of the two transmitting/receiving interface circuits 1 as input and detects the arrival of the simultaneous select signal; 3 is the output of the simultaneous selecting signal detecting circuit 2 and the output of the transmitting/receiving interface circuit 1; The own station select detection circuit takes the output of the 4f own station select detection circuit 3 as an input, generates response data with the own station address set in the address designation section, and sends it to the parent via the sending/receiving 1g interface circuit 1. This is an information transmission control circuit that sends information back to station M.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to the time chart of FIG. 2.

First, the master station M connects each terminal device Al *At...AN
Send select signals to all at once. When the transmitting/receiving interface circuit 1 receives the single select signal tg sent from the master station M through the data transmission line Lt, it sends it to the simultaneous select signal detecting circuit 2. When the simultaneous select signal detection circuit 2 detects the arrival of the simultaneous select signal, it generates a signal indicating the arrival timing and sends it to the own station select detection circuit 3.

Next, this local station select detection circuit 3 waits for local station selection detection upon arrival of the -intermediate select signal, and then monitors the response signal Jpy sent back from each terminal device, and selects the one before the preset one. After the response signal from the terminal device ends, a request to transmit the own station's response data is sent to the information transmission control circuit 4, and the information transmission control circuit 4 generates response data with the own station's address set in the address designation section. , and is sent back to the master station M via the transmit/receive interface circuit 1.

As is clear from the functions of each circuit 1 to 40 in FIG. 1 and the time chart shown in FIG. 2, in the data transfer system of the present invention, the master station M
...Sends select signals to the AN all at once, and selects this section [
After the transmission of the /cut signal is completed, one predetermined terminal device that has been designated to transmit in advance returns a response first, and after the completion of the response, the second, third, and subsequent terminal devices are sequentially preset. It has means for returning responses in order.

In addition, in each terminal device AIy4 ......AN, if the previous terminal device f, which sends the response data that is the trigger for the own station to transmit, is due to some kind of problem and is unable to transmit and fc@ After a preset period of time,
It shall transmit its own response data.

〔Effect of the invention〕

As explained above, if the present invention is implemented, all polling can be performed from the master station all at once, and furthermore, each data terminal device can transfer data to jI8 immediately after the response from the previous data terminal device is completed. B: Since the time required to return responses from all four terminal devices can be shortened even with conventional devices, and a constant data transfer method can be realized, the practical effect is extremely large.

[Brief explanation of drawings]

Fig. 1 is a block opening showing an embodiment of the present invention, Fig. 2 is a time chart for explaining the operation of Fig. 1, and Fig. 3 is a diagram illustrating the multi-drop type pleat connection in the prior art and the present invention. The second block diagram and FIG. 4 are time charts for explaining the operation of the conventional system. M... Master station, AI-AN... Terminal device, 1...
... Transmission/reception interface circuit, 2... - Simultaneous selection word detection circuit, 3... Local station selection detection circuit, 4
・・・・Report transmission/prisoner control circuit.

Claims (1)

[Claims] In a data transfer method in which the master station simultaneously issues a select signal to a plurality of terminal devices connected to a master station in a multi-drop format and transfers data from the terminal devices, the master station sends a select signal to the plurality of terminal devices. A select signal is transmitted all at once, and after the end of the transmission of this select signal, one predetermined terminal device that has been designated to transmit in advance returns a response, and after that response, the second, third, and subsequent terminal devices A data transfer method characterized by comprising means for sequentially returning responses in a preset order.