JPS58148542A - Polling system - Google Patents

Abstract

PURPOSE:To prevent the crosstalk of a central station in advance, by relaying a terminal station call signal from the central station at a relay station, transmitting the signal to each channel, discriminating to which channel the call signal corresponds, and selecting the channel only connected with the terminal station to be called. CONSTITUTION:The central station 1 and a relay station 2 are connected with a channel 4 and a plurality of terminal stations 3 are connected to the relay station 2 with a channel 5. A channel distribution circuit 21 of the relay station 2 transmits the station number of the terminal station 3 transmitted by the central station 1 to each channel 5, a station number reception circuit 22 discriminates the station number and controls a channel selection circuit 23. The channel 5 corresponding to the station number discriminated at reception circuit 22, the terminal station 3 only connected to the channel 5 is selected, allowing to prevent the crosstalk at the central station 1 in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a polling method for reliably transmitting and receiving information from a central station to terminal stations connected to a plurality of communication paths via relay stations.

(Background Art) A conventional communication system to which the present invention is applied is shown in FIG. In FIG. 1, 1 is a central station, 2 is a relay station, 3 is a terminal station, 4 is a communication path between the central station and the relay station, 5 is a communication path between the relay station and the terminal station, and 21 is a communication path. The distribution circuit 22 is a communication path synthesis circuit.

Conventionally, when a central station 1 communicates with a specific terminal station 3, the central station 1 sends the station number etc. to all communication lines 5 to which the terminal stations 3 are connected via the relay station 2, and each terminal station 3 Only the terminal station that receives that signal and corresponds to that station number responds. At this time, the relay station handles all communications! l! 5 signals are combined and sent to the central station l.

Therefore, in this case, the signal sent from the relay station 2 to the central station 1 has the disadvantage that noise on the communication line between the relay and the terminal station, to which no signal is sent, is also synthesized.

(Problems to be solved by the invention) The present invention aims to improve the above-mentioned drawbacks of the conventional technology, and is characterized in that a central station and a plurality of terminal stations are connected via a relay station by a plurality of communication paths, and the central station In the polling method in which the central station and selected terminal stations communicate according to instructions, the relay station relays the terminal station paging signal from the central station and sends it out to each communication channel, and also determines which communication channel the paging signal is sent to. When it is determined whether the terminal station is compatible and the return message from the terminal station is sent back to the central station, only the communication path to which the called terminal station is connected is selected and relayed to the central station. Structure and operation) FIG. 2 shows a first embodiment of the present invention, in which 1 is a central office, 2 is a central office, and 2 is a central office;
is a relay station, 3 is a terminal station, 4 is a communication path between the central station and the relay station, 5 is a communication path between the relay station and the terminal station, 21 to 23
is a configuration circuit in the relay station, 21 is a communication path distribution circuit,
22 is a station number receiving circuit, and 23 is a communication path selection circuit.

To operate this, the central station 1 transmits the station number of the terminal station with which it wants to communicate to the communication path 4 in order to communicate with one terminal station. The relay station 2 sends this station number to all the communication paths 5 to the terminal stations, and at the same time, the station number receiving circuit 22 determines the station number and determines the communication path 5 of the corresponding terminal station 3, and sends the station number to the communication path selection circuit. At step 23, the communication path 5 of the corresponding terminal station and the communication path 4 of the central station 1 are connected.

As explained above, in the first embodiment, there is only one line connected to the central station via the relay station on the line that sends signals from the terminal station, and the noise between the relay station and the terminal station causes the central station to This has the advantage that the signal-to-noise ratio at the central station can be reduced, and that it is possible to prevent some terminal stations from malfunctioning and responding to a communication request even though it is not a request for communication with the central station, causing interference at the central station.

In the first embodiment, all the lines are of the four-wire type, but even if the lines are of the two-wire type as shown in FIG. 3, the same effect can be obtained. In Figure 3, 1 is a central station, 2 is a relay station, 3 is a terminal station, 21 is a station number receiving circuit, 22 is a communication path selection circuit, 4 is a communication path between the central station and the relay station, and 5 is a relay It is a communication path between a station and a terminal station.

To operate this, the line selection circuit 22 of the relay station 2 is closed in advance to connect all the lines, and the central station 1 sends station numbers to all the terminal stations 3 as in the first embodiment. Thereafter, the relay station 2 uses the station number receiving circuit 21 to connect only the communication path 5 of the corresponding terminal station 3 to the line 4 with the central station using the communication path selection circuit 22, and opens the other communication paths 5.

As explained above, the second embodiment also produces the same effects as the first embodiment.

In the first and second embodiments, the case where there is one relay station has been described, but as shown in FIG. 4, the same effect is produced even when a plurality of relay stations are configured. In the tJIJ4 diagram, 1 is the central station, 2 is the parent relay station, 3 is the communication path between the central station and the parent relay station, 4 is the child relay station, 5 is the communication path between the parent relay station and the child relay station,
6 is a terminal station, and 7 is a communication path between the child relay station and the terminal station.

To operate this, the central station 1 transmits the station number of the terminal station 6 with which it wants to communicate to the communication path 3 in order to communicate with one terminal station. The parent relay station 2 connects all communication paths 5 to the child relay station 4.
At the same time as sending out this station number, the station number is received in the same manner as in the first and second embodiments, and the communication path 5 and the communication path 3 are connected to the child relay station 4 to which the corresponding terminal station 6 is connected. Similarly, the child relay station 4 sends out this station number to all the communication paths 7 to the terminal station 6, and also connects the communication path 7 with the corresponding terminal station 6 and the communication path 5 with the parent relay station.

As explained above, the third embodiment also produces effects similar to those of the first and second embodiments.

(Effects of the Invention) The present invention is characterized in that there is only one line connected to the central station via a relay station on the line for transmitting signals from the terminal station, and the signal-to-noise at the central station due to noise between the relay station and the terminal station is It also has the advantage of reducing interference in the central station due to one terminal station malfunctioning and responding even though it is not a request for communication with the current station.
It can be used in systems where a large number of terminal stations are connected in a star configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional communication system, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is a block diagram of an embodiment of the present invention in which the communication path is a two-wire system, and FIG. The figure is a system diagram of an embodiment in which there are a plurality of relay stations according to the present invention. (Explanation of symbols (Figure 2)) 1: Central station, 2: Relay station, 3: Terminal station, 4.5: Communication path, 21: Communication path distribution circuit, 22: Station number receiving circuit, 23: Communication path selection circuit. Special Note Applicant Oki Electric Industry Co., Ltd. Patent Application Agent Patent Attorney Megumi Yamaki - Procedural Amendment (
Voluntary) December 7, 1980 Director General of the Patent Office Kazuo Wakasugi 1. Indication of the case 1982 Patent Application No. 30556 2. Name of the invention Polling method 3. Person making the amendment Relationship with the case Patent applicant name Title (029) Oki Electric Industry Co., Ltd. 6, Contents of amendment (1) Amend "all communication lines 5" in line 9 of page 2 of the specification to "all communication channels 5." (2) Correct "1 communication line 5" on the 12th line of the same page to "communication path 5." (3) Correct “communication line” in lines 14-15 of the same page to “communication path 1.”

Claims (1)

[Claims] In a polling method in which a central station and a plurality of terminal stations are connected via a relay station via a plurality of communication paths, and the central station and selected terminal stations communicate according to instructions from the central station, the relay station receives information from the central station. In addition to relaying the terminal station paging signal and sending it out to each communication channel, it is determined which communication channel the paging signal corresponds to, and when the return signal from the terminal station is sent back to the central station, the terminal station A polling method that selects only the communication path to be connected and relays it to the central station.