JPS6219100B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a line concentrator and relay device connected between a master station and a plurality of slave stations for transmitting data between these stations.

When performing data transmission between one master station and a plurality of slave stations, a polling method can be used if the AC transmission method is used, but this cannot be used with the DC transmission method. Therefore, in the DC transmission system, a concentrator relay device installed between a master station and multiple slave stations is equipped with a transmitting/receiving circuit corresponding to the master station and a plurality of transmitting/receiving circuits corresponding to each slave station, and Data was temporarily stored in a buffer consisting of a memory circuit, etc., and then the data was transmitted. For this reason, the line concentrator repeater required as many transmitting and receiving circuits as the number of slave stations, and also had to be equipped with a memory circuit, a parallel-to-parallel, parallel-to-serial conversion circuit, etc., resulting in a complicated configuration. .

An object of the present invention is to provide a concentrator relay device with a simple configuration.

Embodiments of the present invention will be described in detail below with reference to the drawings. The present invention is applied, for example, to data transmission between a center and variable road signs, traffic information display devices, traffic information collection devices, etc. installed at various locations in a centralized traffic control system.
It is suitable for collecting information from these devices and devices, and controlling and monitoring these devices and devices.

In FIG. 1, a master station (center) 1 and a plurality of slave stations (road signs) 2 are connected via a wire concentrator 3 via a wired line. Also, if necessary, the master station 1
and slave station 2 are directly connected. The remote monitoring and control device 11 installed in the master station 1 includes a direct current signal transmitting/receiving section 13 equipped with a concentrator repeating device 3 and transmitting/receiving circuits 12 as many as the directly connected slave stations 2, and A code conversion unit 15 including a direct and parallel switching circuit 14, a traffic control operation monitoring panel 20,
It is comprised of an interface section 19 including an input circuit 17 and an output circuit 18 for the monitoring panel 20, and a control section 16 common to the operation monitoring panel 20, code conversion section 15, and the like. A sign switching command signal inputted from the operation monitoring panel 20 is transmitted from the remote monitoring and control device 11 to the slave station 2 via the concentrator relay device 3 or directly. In addition, the indicator status or switching confirmation signal from each slave station 2 is transmitted to the master station 1 via the concentrator relay device 3 or directly to the operation monitoring panel 20.
will be displayed.

FIG. 2 shows the configuration of the line concentrator relay device 3.
The line concentrator relay device 3 includes a terminal section 31 and a transmitting/receiving section 32 for the master station 1, and a terminal section 33 and a transmitting/receiving section 34 for the plurality of slave stations 2. The transmitting/receiving section 32 for the master station consists of a line interface 35 and a timing control circuit 36, and the transmitting/receiving section 34 for the slave station consists of a line interface 37 and a line switching circuit 38. Each line interface 35, 37 includes a modulation/demodulation circuit, an amplification circuit, and the like. The timing control circuit 36 controls the line switching circuit 38 based on the synchronization signal received by the interface 35 from the master station, and the line switching circuit 38 controls the terminal section 33 from No. 0 to No. n. The slave station 2 is sequentially switched to the slave station 2 at regular intervals.

The relay operation by the line concentrator relay device 3 starts from the time it receives the special synchronization signal A from the master station. This synchronization signal A is composed of codes that do not occur in normal data transmission. When a signal is sent from the master station and received by the line interface 35, a carrier detection signal CD and a received data signal RD are sent from the interface 35 to the timing control circuit 36. Upon receiving this, the timing control circuit 36 determines a synchronization signal from the received data signal RD, generates a timing signal TS, and sends it to the line switching circuit 38. Further, the timing control circuit 36 sends a transmission data signal SD and a transmission request signal RS to the line interface 37.

This circuit 38 is not connected to any of the slave stations No. 0 to No. n until the synchronization signal A is sent from the master station, that is, until the line switching circuit 38 receives the timing signal TS. and the timing signal
When the TS is sent, the line switching circuit 38 sequentially switches lines to slave stations No. 1 to No. n at fixed time intervals T to connect the lines.

FIG. 3 shows the operation of such a line concentrator relay device 3. Referring to this figure, upon receiving the standard signal A from the master station, slave station No. 0 is first selected.
The signal X1 from the master station is sent from the interface 35 to the timing control circuit 36 as a received data signal RD.
Then, it is sent from the timing control circuit 36 to the interface 37 as a transmission data signal SD, and further transmitted to the slave station No. 0 via the switching circuit 38 for a certain period of time t1. After the slave station No. 0 receives this signal
signals Y and Z are sent to the line concentrator relay device 3. Here, signals Y and Z are signals containing data from the slave station. These signals Y and Z are received by the interface 37 as the reception data signal RD, and directly passed through the timing control circuit 36 as the transmission data signal SD.
The data is sent to the interface 35 as a file, and transmitted from this interface 35 to the master station. When receiving the signals Y and Z, the interface 37 outputs the carrier detection signal CD to the timing control circuit 36.
Send to. In this way, data is transmitted and received in real time between the master station and slave station No. 0 via the line concentrator relay device 3. Then, when the time T allocated to slave station No. 0 has elapsed, the switching circuit 3
8, the line is switched to slave station No. 1, so
In the next time period T, communication is performed between the master station and slave station No. 1. In the same way, the slave stations are switched every time T, and when it goes around to slave station No. n (one cycle TC ends), the line concentrator 3 releases the line on the slave station side, and receives a synchronization signal from the master station. It will be in a standby state until A is sent.

Note that switching of the slave station is performed when data is not being transmitted or received between the relay device 3 and the slave station 2. This is done by providing an appropriate phase difference between the timing signal TS for line switching sent from the timing control circuit 36 to the line switching circuit 38 and the transmission request signal RS, and setting the timing signal TS when the transmission request signal RS is off. This is achieved by outputting the signal TS.

FIG. 4 shows another embodiment. In this example, the transmission between the master station 1, the concentrator relay device 3, and the master slave station 5 is an AC system, and the transmission between the concentrator relay device 3 and the slave station 2 is a DC system. The transmission line between the master station 1 and the main slave station 5 constitutes a main channel, and this line is a high-speed data transmission line that is always connected. In addition, the transmission line between the master station 1 and the concentrator repeater 3 is assigned as a subchannel, and is superimposed on the main channel by frequency multiplexing.
The signals are separated by a duplexer 4. This sub-channel is time-divided into a plurality of slave stations 2 by the line concentrator 3 as described above.

As described above, according to the present invention, only one transmitting/receiving circuit for the slave stations provided in the line concentrator and relay device is required, and data can be transmitted with a plurality of slave stations. Further, the line concentrator repeater does not require complicated circuits such as parallel/parallel converter circuits and storage circuits. Therefore, the configuration of the relay device becomes very simple. Furthermore, since there is no need to add the address of the slave station to the transmission information, the amount of transmission can be reduced by that amount and transmission efficiency can be improved, and since the relay device has an amplification function, it is reliable. Communication can be carried out. By providing the concentrator repeater with a modulation method conversion function, even if the transmission speed and code structure are the same, the modulation method and current format (metallic return, earth return, etc.) of the master station and substations are different. connection is possible even if there are

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the overall configuration, Figure 2 is a block diagram showing the overall configuration.
FIG. 3 is a block diagram showing the line concentrator repeater, FIG. 3 is a time chart showing the operation of signal transmission, and FIG. 4 is a block diagram showing another embodiment. 1... Master station, 2... Slave station, 3... Line concentrator relay device, 32, 34... Transmitting/receiving unit, 35, 37... Line interface, 36... Timing control circuit, 38... Line switching circuit.

Claims (1)

[Scope of Claims] 1. A line concentrator relay device connected between a master station and a plurality of slave stations that sends out a synchronization signal with a specific code for starting communication with the slave stations; a first transmitting/receiving circuit that transmits and receives signals to and from the station; a second transmitting and receiving circuit that is connected to the first transmitting and receiving circuit on one input/output side and transmits and receives signals to and from the slave station; A line switching circuit that sequentially switches and connects the other input/output side of the second transmitting/receiving circuit to one of the lines to a plurality of slave stations at fixed time intervals; and for data transmission between a master station and a plurality of slave stations, comprising: a timing control circuit that detects the synchronization signal from among the transmitted signals and controls the line switching circuit based on the detection of the synchronization signal. line concentrator relay equipment.