JPS58187042A - Data transfer system - Google Patents

Abstract

PURPOSE:To extent the transmission distance of information exchange and to increase the number of slave stations possible for connection, by inserting the transfer information of station itself to an overhead bit only when a call signal is generated from a master station. CONSTITUTION:When a master station calls out another slave station and it is not required to transfer data from a data terminal device of one slave station, a signal from a data terminal device 3 to a control circuit 18 is zero. A control output signal 19 of the circuit 18 is made to 1 level at all times and a base band digital signal including overhead bit information from a low-order station is inputted to an input terminal of a coupling circuit 15 as it is. In this case, an output signal 23 from an MODEM 2 of the station itself has only to be inhibited by receiving the control signal from the device 3 at the circuit 15, and the overhead signal from the low rank station is transferred to the master station directly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a digital transport system (overdriver) 1-
In a system in which information is exchanged between at least one slave station and one master station, in order to send and receive information between the data terminal device of the slave station and the digital transmission path,
The present invention relates to a data transfer method in which information is exchanged by means of a polling operation from a master station.

In order to exchange analog information between a master station and a slave station using a digital transmission type overhead pilaster, at least a kneader/decoder for converting into or inversely converting into digital code is required.

An example of the information exchange will be explained in detail with reference to FIG.

Information transferred from the master station is sent to the digital relay device 110 of the first slave station through the transmission path 411.

The digital relay device 110 extracts only the necessary overhead pits, decodes the digital information in the decoder 111, converts it into analog information, and sends it to the modem interface 210. The analog information is transmitted to branch circuit 2 within modem interface 210.
The signal is branched into two at 12, and one is sent to modem 211. The other side is again sent to the coder 112 of the digital relay device 110, digitally encoded, and transferred to the next transmission line 41.
2 and is sent to the digital relay device 120 of the primary slave station, and after going through the same process as the first slave station, is sent to the branch circuit 222 in the modem interface 220, one being the modem 2211 and the other being the relay device. coder 122 in 120
is sent to the next slave station.

In this way, the information sent from the master station must pass through N coders/decoders in the repeaters of the slave stations between them until it reaches the Nth slave station which is the farthest away.

On the other hand, the analog information sent from the Nth slave station is sent from the modem 2N1 in the modem interface 2NO, and is sent through the 1st branch circuit 2N3t-way to the digital terminal relay device IN.
It is input to coder IN3 in
It is sent to the preceding slave station through Nt. Data transfer from the slave station to the master station is also sequentially transferred to the master station via the decoder/coder 1- of the slave station, similar to the data transfer from the master station to the slave station.

In this way, in order to exchange data between the Nth slave station farthest from the master station and the master station in data exchange by polling operation, in the information exchange established between them,
Similarly, each coder/decoder tube must pass N-1 times.

The above method has the following disadvantages.

In other words, in the conventional system, in order to exchange information between a slave station that is farthest from the master station and the master station, it is necessary to pass through a large number of PCM coders/decoders in the relay equipment installed between them. In addition, quantization noise and no-call noise generated in the PCM coder/decoder are added, and group delay distortion generated in the filters in the PCM coder/decoder is added, causing problems in data transmission.

There are limits to the maximum distance between the master station and slave stations, the number of slave stations connected in tandem, or the number of routes connected from the master station in general, so there is a limit to the number of routes, and system design This meant that there was less freedom.

The purpose of the present invention is to solve the above-mentioned drawbacks in a system for exchanging information between a master station and a slave station by using overhead pits in a digital transmission system, without being limited by the influence of noise, etc. It is an object of the present invention to provide a data transfer method that can extend the transmission distance for information exchange and increase the number of connectable slave stations.

In other words, the present invention provides a circuit for inserting and extracting an overhead pit signal from a baseband signal of digital transmission in a digital relay device installed in a slave station, by inserting the transfer information of the own station into the overhead pit signal, or by inserting the transfer information of the own station into the circuit for inserting and extracting the overhead pit signal from the baseband signal of digital transmission. On the other hand, the own station has a switching circuit that allows the transfer information from a remote station (hereinafter referred to as a lower station) to be passed through without going through the PCM coder and decoder, and when a call signal is received from the master station. When a slave station other than the own station is called, the PCM coder inserts the transfer information of the own station into the overhead pit.

Tecoder T - A data transfer method that allows you to transfer data smoothly and without any interference.

FIG. 2 shows the main parts of an embodiment of the data transfer method according to the present invention, and shows the digital relay device 1, modem 2, and data terminal installed in the slave station when information is exchanged by polling operation from the master station. A connection diagram of the transmitting side of the device 3 is shown.

When exchanging information between a master station and multiple slave stations using polling operations.

A certain slave station receives a calling signal from the master station,
Needless to say, there are cases in which the information is transferred to the master station, and cases in which a slave station other than the own station is called and there is no need to transfer the information of the own station to the master station.

When a slave station is called by the master station and transfers information to the master station, the data terminal device 3 sends the control signal 22 of R8 (request send) as 1' to the modem 2, and also sends the control signal 22 of the digital relay device 1 as 1'. It is sent to the digital combination circuit 15 and the control circuit 18.

If information is not to be transferred to the master station, the data terminal device 3 similarly sends out a control signal 22 of 10'.

In FIG. 2, a terminal 11 is an input terminal for a baseband digital signal containing overhead binoto information from a lower station.The signal is input to an interface 121C, and after the bipolar signal is converted into a unipolar signal, the main signal is 13, one input terminal of the next gate circuit 14 is input.

A control signal from the data terminal device 3 is input as a control output signal 19 to the other input terminal of the gate circuit 14 via the control circuit 18 . In other words, when the slave station is called by the master station by polling operation and needs to transfer all information to the master station, the control signal 22 from the data terminal device 3 becomes %11, and the control signal 22 becomes %11. The circuit 18 is a baseband main signal 1 including an overhead pit.
From 3.

A control output signal 19 that inhibits only the overhead pit signal is input to one input terminal of the gate circuit 14, and the output 20 of the gate circuit 14 receives only the main signal that does not include the overhead pit signal.
5 is input.

On the other hand, data from the data terminal device 3 of the local station is sent to the modem 2, further converted by the coder 21 into a pit digital signal, for example 64, and inputted to the other input terminal of the coupling circuit 15.

That is, when a polling operation is called by the master station, the data from the data terminal device 3 is transferred to the coupling circuit 15.
As a result, the unipolar signal is combined with the main signal from the lower station, and then the unipolar signal is converted into a bipolar signal by the interface circuit 16 and then sent to the output terminal 17.

Also, when another slave station is called by the master station and there is no need to transfer data from its own data terminal device,
The signal from the data terminal device 3 to the control circuit 18 is always set to %0', and the control output signal 19 of the control circuit 18 is always set to 11', so that the baseband digital signal containing overhead pit information from the lower station is transmitted. is input as is to one input terminal of the coupling circuit 15. At this time, the output signal 23 from the modem 2 of the own station may be inhibited by receiving the control signal from the data terminal device 3 in the coupling circuit 15, and the output of the coupling circuit 15 may be inhibited by the control signal from the data terminal device 3. Overhead signals will be transferred directly to the master station.

Note that the coupling circuit, gate circuit, etc. can be replaced with other selectors, etc.

FIG. 3 is an example of an application in which the present invention is used to centrally monitor fault information.

In the figure, 30 is a centralized monitoring device installed at the master station, and 4
0 to 44 are failure monitoring devices installed in slave stations. Generally, there are a plurality of routes connected to the master station, and this example shows a case where four routes are connected.

Through the polling operation, the central monitoring device 30 sequentially calls out the fault monitoring devices of the slave stations through all the terminal relay devices 31 to 34 and the transmission lines 50 to 56, and the fault monitoring devices of the called slave stations receive information from the outside. By sending fault information 61 to 65tl to the central monitoring device 3o, fault conditions of devices such as transport devices installed in each slave station are centrally monitored.

As is clear from the above description, according to the present invention.

In a system in which information is exchanged between a master station and multiple slave stations through polling operations, PCM coder ,
It is possible to extend the transmission distance between the master station and slave stations, or increase the number of slave stations that the master station can cover, without being affected by noise and group delay distortion generated by the decoder.
It is possible to obtain an economical and highly reliable digital relay device that has a large degree of freedom in system design and has a small circuit configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional information transfer method, FIG. 2 is a block diagram showing main parts of an embodiment of the information transfer method according to the present invention, and FIG. 3 is a block diagram showing an application example of the present invention. be. 110.120...Digital relay device, INO
...Digital terminal relay device, 210, 220.
...2N0...Modem interface installed in the slave station, 310, 320. ...3NO...
Data terminal equipment installed in the slave station, 411, 412, 4
13. ...41N...Transmission line, 421,422
, 423. ...42N...Transmission line, 111,
121.・・・INI・・・Decoder, 112
,122...Coder, 113,123...I
N3...: I-dar-, 114, 124...
...Decoder, 211, 221. ...2N1...
...Modem, 212.222.・・・2N2・−・・
...Branch circuit, 213°223.2N3...Coupling circuit, 1...Digital relay device, 2...
...Modem, 3...Data terminal equipment, 11...
...Input terminal, 12.16...Interface circuit, 13...Main signal transmission path, 14.
...Gate circuit, 15 ... Digital coupling circuit, 17 ... Output terminal, 18 ... Control circuit, 19 ... Control output signal, 20...
...Output, 21...Coder, 22...
・Control signal% 23... Output signal, 30...
...Intensive monitoring equipment installed at the master station, 31-34...
...terminal relay device installed at the master station, 35.36.3
8... Relay device installed in the slave station, 37...
...terminal relay device installed in the slave station, 40 to 44...
...Fault monitoring device, 50-56...Transmission path, 61-65...Fault information.

Claims (1)

[Claims] Using a digital transport method overhead Piratra, at least one slave station and one master station are connected via a transmission path and a digital relay device! In the data transfer method for exchanging information, there is a function to inhibit the information from the lower slave station when transmitting the own station's information to the digital relay device installed in the slave station, and a function to inhibit the information from the lower slave station when transmitting the own station's information to the digital relay device installed in the slave station. A data transfer method in which a switching circuit with a function of passing information from a lower-order slave station is provided, and the switching circuit is operated by a control signal from a data terminal device.