JPS5923498B2 - Relay method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a relay system that makes it possible to send and receive signals between a central device and terminal devices by exclusively using the same line.

As shown in FIG. 110, the automatic meter reading system for cumulative power consumption includes a central device 1 that reads data, a relay device 3, a high voltage distribution line (or communication line) 2 as a transmission path,
There is one in which terminal devices 4, 4, . . . are arranged in groups divided by 3, .

The central device 1 is placed on the high voltage side of, for example, 6.6 KV, and the terminal device 4 15 is placed on the low voltage side of about 100V. Then, only the relay devices 3, 3, etc. specified by the central device 1 are connected to the central device 1 and its relay devices 3.
The function is to form a signal transmission path between the terminal device 4 and the terminal device 4 that is subordinate to the terminal device 4. 20 As the above-mentioned relay device, one configured as shown in FIG. 2 is conventionally known.

In the figure, 5a is a receiving circuit that receives a calling signal fl from the central device, 6a is a frequency conversion circuit that converts the frequency of the calling signal fl into a calling signal f2, and 7a is a calling signal 25f2.
These are the amplification circuits that amplify and send out the signals, and these are the main parts of the first relay system that forms a signal transmission path from the central device 1 to the terminal devices 4 (downward direction). 5b is a receiving circuit that receives the response signal f3 from the terminal device 4, 6b is a frequency conversion circuit that converts the frequency of the response signal f3 into 30 response signal f4, and Tb is an amplifier circuit that amplifies the response signal f4. It is a main part of a second relay system that forms a signal transmission path from the device 4 to the solid device 1 direction (upward direction).

35 These first and second relay systems are used exclusively because there is a one-way transmission path between the central device 1 and the terminal device 4.

This switching control is performed by switching devices 9a and 9b.

The switch 9a normally connects the solid device 1 and the receiving circuit 5a in the first relay system, but when the receiving circuit 5b in the second relay system detects a signal, the same signal is detected. During this period, the solid device 1 and the amplifier circuit 7b are connected.
The switch 9b normally connects the low voltage coupler 8 and the receiving circuit 5b in the second relay system, but when the receiving circuit 5a in the first relay system detects a signal, the same signal is detected. During this period, the amplifier circuit 7a and the low voltage coupler 8 are connected. With the above-described configuration, when the calling signal f1 arrives from the solid device 1 and the receiving circuit 5a detects that this signal f1 is a calling to itself, the calling signal f1 is
is frequency-converted by the frequency conversion circuit 6a and becomes the calling signal F2.
It is transmitted to each terminal device 4, 4, . . .

Upon receiving this calling signal F2, each terminal device 4, 4,...
* generates a response signal F3 during a transmission period that is set in advance to be different between each terminal, and sends this response signal F3 to the relay device. When these response signals F3 arrive, the relay device transmits each of the response signals F3 to the receiving circuit 5.
After receiving it at the frequency conversion circuit 6b, the frequency is converted by the frequency conversion circuit 6b,
The response signal F4 obtained thereby is sent to each solid device. That is, when the response signal F3 arrives, the relay device performs frequency conversion on the signal F3 and sends it to the solid device without determining whether or not it is the true response signal F3. However, with such a relay device, the force direction of the transmission path is determined by whichever of the receiving circuits 5a and 5b detects the signal first, so the following 5.
This will cause problems like this.

(1) When noise occurs in the low voltage system, the receiving circuit 5b detects it and operates the switch 9a to form an uplink, so even if a regular call signal f1 is sent from the solid equipment 1 during this period. I can't react to this. (2) Said (
When an uplink is formed due to the same cause as in 1), the noise-based signal shown in Figure 3a is sent to the high-voltage distribution line 2 as shown in the shaded area A in Figure 3b, and is transmitted from other relay equipment. response signal B. Generally, a plurality of relay devices 3, 3...
is selected in a time-division manner by the solid device 1, so the four transmission signal frequencies F4 are made equal in all the relay devices 3, 3, . . . . Therefore, if the signals A and B described above coexist, the solid device 1 will not be able to distinguish between them, and will receive erroneous data. The present invention enables the first and second relay systems to operate exclusively and sends a response signal received from a terminal device to a solid device without performing code verification or the like. A relay system capable of stably and reliably relaying signals by reducing the influence of noise etc. by forcibly limiting the operable period of the first relay system according to the signal relay operation of the first relay system using a timer. The purpose is to provide

The details of the present invention will be explained below with reference to FIGS. 4 and 5. FIG. 4 is a block diagram showing one embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. The main difference between this embodiment and FIG. 1 is that the operable period of the receiving circuit 5b in the second relay system is regulated by the operating period of the timer circuit 10. This timer circuit 1
0 is activated by the receiving circuit 5a in the first relay system, and its activation timing and operation period have the relationship shown in FIG. 5c. In FIG. 5, a is a calling signal 8 transmitted from the solid device 1 to the relay device 3, and this calling signal f1 is immediately received by the receiving circuit 5a.

Then, the fifth frequency is converted by the frequency conversion circuit 6a.
The calling signal F2 in FIG. b is transmitted to the terminal device 3 through the converter 9b which is switched by the output of the receiving circuit 5a. When the receiving circuit 5a finishes sending out the calling signal f1, that is, at the end of the calling signal F2, it starts the timer circuit 10. When the timer circuit 10 is activated, the receiving circuit 5b becomes operational and tries to send the incoming signal to the solid device 1 by switching the switch 9a. Therefore, if N terminal devices 4 are connected to the relay device 3, response signals F3 from 1 to N arrive sequentially as shown in FIG. The period must at least cover the response period from all these terminal devices. However, it is not preferable to make it unnecessarily long. Incidentally, FIG. 5e shows the response signal F4 which is frequency-converted and transmitted to the solid device 1.
This is the waveform of In the embodiment, the receiving circuit 5b is controlled by the output of the timer circuit 10, but the path from the receiving circuit 5b to the switch 9a may be controlled.

In addition, the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications. As described above, in the relay system of the present invention in which the operable period of the second relay system is forcibly limited by the timer circuit according to the signal relay operation of the first relay system, the terminal device can Although the system sends the generated response signal to the solid equipment without performing code verification, the possibility that the relay equipment responds to noise on the low voltage side is significantly reduced, and as a result, the response signal from the solid equipment is significantly reduced. Calls can be made reliably, and the possibility that a solid device will affect signals received from other relay devices can be significantly reduced.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing an example of an automatic meter reading system, Fig. 2 is a block diagram showing a conventional relay device, and Fig. 3 is a block diagram showing an example of an automatic meter reading system.
A time chart showing an example of malfunction when using the relay device shown in the figure.
FIG. 4 is a block diagram showing one embodiment of the present invention, and FIG. 5 is a time chart of the same embodiment. 1...Solid equipment, 2...High voltage distribution line,
3... Relay device, 4... Terminal device, 5
a, 5b...Reception circuit, 6a, 6b...
・Frequency conversion circuit, 7a, 7b...amplification circuit,
8...Low voltage coupler, 9a, 9b...Switcher, 10...Timer circuit.

Claims (1)

[Claims] 1 A first relay system that sends a signal from a central device located on the high voltage side or the communication line side to a terminal device placed on the low voltage side; and a second relay system that sends a signal from the terminal device to the central device. In the relay system in which the second relay system exclusively uses the same line and the second relay system supplies the signal from the terminal device to the central device without code checking, the first relay system transmits the signal from the central device to the central device. A timer circuit is provided which emits a permission signal for noise removal for a predetermined period from the time when the second signal is received and sent to the terminal device, and the second signal is transmitted only during the period when the permission signal is generated from the timer circuit. A relay system characterized in that the relay system is enabled to operate, and this period is set as a transmission permissible period for signals emitted from the terminal device.