JPS62225047A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To send a data without causing a contention problem with the same data transmission constitution among plural master stations by using a data transmission section in common with the plural master stations and providing a return signal generating circuit. CONSTITUTION:The detection signal of signal detectors 31-3N is selected with priority by a priority discrimination circuit 4, given to a controller 5, the controller 5 forms a closing control signal in response to the detection signal of the circuit 4, to give an output to a line switch section 2 and switches 61-6N are closed in response to the signal. Thus, the data transmission section 10 in comnon to the plural master stations sends a data from the controller 5 to the master stations and gives the data from the master stations to the controller 5. When a data transmission request signal comes from a line other than the line connected to the section 10, the data transmission signal is returned to the line via normally closed switches 111-11N based on a command given from the controller 5 in the return signal generating circuit 12. Thus, the data is sent without causing contention problem by the same data transmission constitution among plural master stations.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a data transmission device, and can be applied to, for example, a slave station of a remote monitoring and control system.

(Prior Art) In a 1-to-N remote monitoring and control system, for example, one master station sequentially calls a plurality of slave stations by, for example, polling, and controls and monitors them to collect process data scattered at various locations.

However, due to the recent expansion of system scale, the increasing complexity of systems, and the promotion of efficient resource management, multiple master stations M1. M2 is the same slave station (S 1-n or 5
Cases have emerged in which data of 2-m) are collected.

Conventionally, such slave stations that are common to multiple master stations have been configured with separate data and evening transmission devices for each master station, such as modems, parallel/serial, serial/parallel converters, etc. The transmitting and receiving sections, etc., were provided separately for each master station.

Therefore, such slave stations are becoming larger and more complex, which poses a problem, for example, when a slave station must be installed inside a manhole or on a pole where there is not enough installation space.

Furthermore, it would be desirable if the same configuration could be used to transmit data from the same slave station to multiple master stations, since this would further increase the operating rate of the device. However, in the past, separate devices were provided for each master station, so it can be said that there is room for improvement in this respect.

(Problems to be Solved by the Invention) As mentioned above, in order for multiple master stations to collect data from the same slave station, it is difficult to provide a separate data transmission device for each master station in the slave station. This increases the size of the IG, which causes problems in terms of installation space, and it can be said that there is a lot of waste from a cost performance standpoint.

Therefore, the present invention has been made in consideration of the above points.
It is an object of the present invention to provide a data transmission device capable of transmitting data to a plurality of master stations using the same data transmission configuration without causing a conflict problem.

[Structure of the invention] (Means for solving the problem) In order to solve the problem, in the first invention,
Based on the detection signals of the signal detectors 3 blind to 3N provided for each of the lines 11 to 1N connected to the master station, the control device 5 selects a predetermined number of data transmission units whose number is smaller than the number of master stations. 10 was configured to switch and connect the lines according to the detection signal.

Furthermore, in the second invention, in addition,
When a detection signal from a signal detector provided on another line is given while any line is connected to the data transmission unit 10, the control device 5 activates the return signal generation circuit 12 to transmit data to the line. The transmission unit 10 is configured to send a return signal indicating that transmission is in progress with the uncle's station.

(Function) The data transmission section 10 can be used in common by a plurality of master stations (lines 11 to 1N). Therefore, the signal detector 31
The control device 5 performs switching control in response to a detection signal of ~3N. As a result, it has become possible to make slave stations smaller, cheaper, and more effective.

Further, when data transmission request signals are given from a plurality of lines, a return signal is sent for lines other than the line m switched and connected to the data transmission unit 10 to make the master station recognize the status of the slave station. did. As a result, it has become possible to perform appropriate processing on the master station side.

(Embodiment) Part 1: Hereinafter, an embodiment of the first invention will be described in detail with reference to the drawings.

In FIG. 1, lines 1+, 12, . . . , 1N connected to a plurality of (N) master stations (not shown) are selectively connected to the main body of the data transmission device. It is coupled to the line switching section 2.

The line switching unit 2 includes signal detectors 31, 32, . ~3N detection signals are given to the priority determination circuit 4. When receiving detection signals from a plurality of lines, the priority determination circuit 4 selects one of the detection signals with priority according to predetermined conditions and supplies the selected signal to the control device 5 having a central processing unit configuration.

In addition, the line switching unit 2 connects normally open switches 6+, 62...6N corresponding to each line 11 to 1N to the line 11 to 1N.
~1N contact/separation is performed. The control unit @5 forms an opening control signal CON according to the detection signal from the priority determination circuit 4 and provides it to the line switching unit 2, and each switch 61 to 6N is connected to the control unit 5.
It is configured to close in response to a control signal CON from the terminal.

The non-line side terminals of the switches 61 to 6N are connected to a modem 7, a serial-parallel/parallel-serial converter 8. It is connected to a common data transmission section 10 consisting of a transmitting and receiving device 9, and the data transmission section 10 sends data given from the control device 5 to the master station, and also transmits data from the master station to the control device 1f5.
It is designed to be given to Note that this embodiment is configured in full-duplex mode.

In the above configuration, the operation when a data transmission request signal arrives from the master station connected to the line 11 will be explained based on FIG.

When a data transmission request signal arrives as shown in FIG. 2(A), the signal detector 31 corresponding to the line 11 is activated as shown in FIG.
), its arrival is detected as shown in FIG. This detection signal is given to the priority determination circuit 4, and if there is no conflict with other lines or if no transmission command has been set in advance, the detection signal is shown in FIG.
As shown in D), the detection signal from the line 11 is given to the control device 5 as is. As a result, as shown in FIG. 2(E), the control device 5 sends the switching control signal CON to the switching control section 2 to close only the switch 61 corresponding to the line 11, and also sends the data to the data transmission section 10. give. Thus, the switch 6I is closed as shown in FIG. 2(F), the other switches 62 to 6N remain open as shown in FIG. 2(G), and only the line 11 is connected to the data transmission section 10.
is connected to the transmitting/receiving device, which converts the data into data for transmission.
The data is converted into serial data by the serial-parallel/parallel-serial converter 8, modulated by the modem 7, and data is transmitted with a slight delay after the arrival of the data transmission request signal, as shown in FIG. 2(B). Start.

Eventually, when the data is captured in the master station and the digital transmission request signal is released, the switch 61 operates in the same manner.
is released, and the data transmission section 10 ends the transmission mode.

According to the above embodiment, the data transmission device of the slave station which is commonly monitored and controlled by a plurality of master stations is connected to a single modem 7, a serial-parallel/parallel-serial converter 8. It can be configured with the transmitting/receiving device 8, the slave station can be simplified and miniaturized, and the operating rate of the data transmission device can be further increased.

An embodiment of the second invention Next, a third embodiment in which parts corresponding to those in FIG.
An embodiment of the second invention will be described in detail with reference to the drawings.

In FIG. 3, the line switching unit 2 has a
...Switch 11 that is normally closed in response to 1N
1, 112...11N are provided, and a return signal generating circuit 12 is commonly connected to the non-line side terminals of these normally closed switches 111, 112...11N. The return signal generation circuit 12 is connected to a line 1Y (Y
When a data transmission request signal is received from the line 1Y (=1 to N), a data transmission in progress signal is sent back to the line 1Y via the normally closed switch 11Y based on a command given from the control device 5.

Note that the normally closed switches 111 to 11N are normally open switches 61
It is designed to be linked with ~6N.

In the above configuration, the operation when, for example, a data transmission request signal arrives from the line 12 after a data transmission request signal arrives from the line 11 will be described with reference to FIG.

When a data transmission request signal arrives from the line 11, the normally open switch 61 is opened in the same way as in the case of the slave station in FIG.
Data is transmitted via times $111 (th (A), (
E), (G), (L), (J).

(B)). At this time, in order to indicate that data is being transmitted on the line 11, the control device 6 transmits data to other lines 12 to 1N.
A busy signal is raised for each time (Fig. 4 (M)).

When a data transmission request signal arrives from the line 12 at time t2 during data transmission via the line 11 (FIG. 4(C)),
It is detected by the signal detector 32 (FIG. 4(F)), and the detection signal is given to the priority determination circuit 4. Priority judgment circuit 4
is currently being selected for line 11, so it's time! No priority selection operation is performed for 912, and only the arrival of the signal is given to the control device 5 (FIG. 4(H)). Since the busy signal is rising at the time of this arrival, the control device 5 (see Fig. 4 (M))
) Recognizing that data is being transmitted, the switches 62 and 112 are not operated (FIG. 4 (L)), the return signal generation circuit 12 is left connected to the line 12, and the return signal generation circuit 12 is connected to the line 12. Sends a return signal to the line 12 indicating that data is being transmitted on the line (Figure 4 (D))
.

The master station side recognizes the return signal indicating that data is being transmitted for the other line and sends the data transmission request signal at time t3.
When no more signals arrive, the sending of the return signal ends in the same way (Fig. 4 (C), (F), (H), (M), (D)).
).

Therefore, according to this embodiment, in addition to the effect that the configuration of the slave station as described above can be reduced in size and that the operating rate of the device can be increased to achieve effective utilization, the data transmission section 10 can be
This also has the effect that the master station that could not connect to the base station can accurately and quickly recognize the reason for the failure to connect (data transmission with another station, hence 14), and can take appropriate measures.

blood! In the above embodiment, the data transmission section 1o has a single configuration, but the data transmission section may be provided so as to be common to a plurality of lines. A plurality of pieces smaller than the number may be provided.

Further, the system may be one in which the slave stations are monitored and controlled by a plurality of master stations, and the number of master stations is not limited to N as in the above embodiment.

Furthermore, in the above-described embodiment of the second invention,
Although the content of the return signal was "transmitting data with another station", a return signal containing "failure" may also be transmitted.

[Effects of the Invention] As described above, according to the first aspect of the present invention, the data transmission unit is commonly used in a plurality of master stations, so it can be made smaller and cheaper, and the required installation space can be reduced. In addition, it is possible to increase the frequency of use of the data transmission section and effectively utilize its functions.

In addition to this, according to the second aspect of the present invention, a return signal generation circuit 12 is provided to send a return signal for a line that is not connected to the data transmission section 10, which is why data cannot be transmitted on the master station side. be able to quickly and accurately recognize and respond appropriately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the data transmission device according to the first invention, FIG. 2 is a timing chart of each part thereof, and FIG. 3 is a block diagram showing an embodiment of the data transmission device according to the second invention. 4 is a timing chart of each part thereof, and FIG. 5 is a route map showing an example of a supervisory control system to which the present invention is applied. 11-1N...Line 2...Line switching section 31-3N...Signal detector 5...Control device 61-6N, 111-11N...Switch 10...
Data transmission section 12...return signal generation circuit

Claims (2)

[Claims] (1) In a data transmission device installed in the slave station in a remote monitoring and control system in which a plurality of master stations monitor and control one slave station, a number of data transmission units smaller than the number of master stations and each of the master stations are connected to each other. A signal detector for detecting a data transmission request signal provided for each line to be connected is provided, and the control device switches and connects the data transmission section and the line when a detection signal from the signal detector is given. A data transmission device characterized by: (2) In a data transmission device installed in the slave station in a remote monitoring and control system in which a plurality of master stations monitor and control one slave station, each of the master stations has a data transmission unit that is smaller in number than the number of master stations, and a signal detector for detecting a data transmission request signal provided for each line connected to the data transmission section, and generating a return signal corresponding to the data transmission section indicating that the data transmission section has already been switched and connected. and a return signal generating circuit, the control device switches to the line corresponding to the signal detector if the data transmission section is not connected to any line when the detection signal from the signal detector is applied. If the data transmission unit is connected to any line, the return signal generated by the return signal generation circuit is sent to the line corresponding to the signal detector when the signal detector detects the signal. A data transmission device characterized by transmitting.