JPS59198062A - Remote typewriter control system - Google Patents

Abstract

PURPOSE:To restore automatically a modem and a network controller after the end of data transfer by providing a cut-off signal generating means cutting off a terminal device ready signal of a typewriter based on a carrier detecting signal of the modem between the modem device and a typewriter. CONSTITUTION:A maintenance station network controller 10 and a maintenance station modem 11 are connected sequentially to a subscriber line of an exchange of a maintenance station. A modem adaptor 13 being a cut-off signal generating means cutting off a terminal device ready signal of the typewriter 12 based on a carrier detecting signal of the maintenance station modem 11 is provided between the maintenance station modem 11 and the typewriter 12. Then, the maintenance station network controller and the maintenance station modem are restored automatically without requiring a maintainer to operate manually the typewriter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a remote typewriter for controlling a remote typewriter installed in a maintenance station located far from an unmanned switching center or the like.
Related to typewriter control system.

As a conventional remote typewriter control system that uses the general line of an exchange, there is one shown in FIG. 1, for example. In FIG. 1, a slave station that receives maintenance from a maintenance station in a remote location has a transfer control device (TC) 3 connected to a central control device (CC) 1 via an order bus (BUD), A slave station modulator/demodulator (MD) 5 and a slave station network control unit (NCU) 6 are connected to this.
is connected to the subscriber circuit of the switch path switch (SW) 4 of the exchange. On the other hand, the subscriber circuit of the maintenance station exchange includes a maintenance station network control unit (NCU) 1o, a maintenance station modem (MD) 11, and a typewriter (TTY) 12.
are connected in sequence, and a general subscriber number is assigned to this maintenance station network control device 10.

In this type of conventional remote typewriter control system, to explain the procedure for a slave station to transfer data to the typewriter 12 of a maintenance station, first, data is transferred from the slave station's communication path controller (SPC) 2 to the slave station's When a calling command is sent to the network control device 6 and the slave station exchange detects the call from the slave network control device 6, it establishes a hotline connection and calls the maintenance station network control device 10.
An outgoing connection is made using the subscriber number of , as the terminating number, and the call is received to the maintenance station network control device 10 to which the typewriter 12 of the maintenance station is connected. The maintenance station network control device 10 performs a ring trip based on the terminal equipment ready (ER) signal of the typewriter 12, and the incoming trunk (ICT) 9 of the maintenance station sends a response signal to the outgoing trunk (OCT) 7 of the slave station. return. Finally, a communication path is formed from the slave station network control device 6 to the maintenance station network control device 10, and data transfer by the slave station modulation/demodulation device 5 is carried out.

By the way, when the terminal device ready (ER) signal of the typewriter 12 is disconnected after the data transfer is completed, the maintenance station modem 11 and the maintenance station network control device 10 are restored, and the communication between the slave station and the maintenance station is restored. The communication path is opened, and both the slave station network control device 6 and the slave station modulation/demodulation device 5 are restored.

However, this kind of conventional remote typewriter
In the control method, after the data transfer is completed, the maintenance station network control device 10 and the maintenance station modulation/demodulation device 11 are restored unless the maintenance person manually operates the telephone key of the typewriter 12 to disconnect the terminal device ready signal. Furthermore, even if a call is received from a general subscriber by mistake, the maintenance station network control device 10 and the maintenance station modulation/demodulation device 11 do not recover after the data transfer is completed.

The present invention has been made in view of the above-mentioned drawbacks, and has the purpose of making it possible to connect the maintenance station network control device and the maintenance station without the maintenance person manually operating the typewriter when receiving an incoming call to the typewriter of the maintenance station. This invention provides a remote typewriter control method that can automatically restore the station modem.

The remote typewriter control system according to the present invention is provided with means for disconnecting the typewriter's terminal device ready signal based on the carrier detection signal of the modem and the modem between the modem and the typewriter. Another feature is that the modulation/demodulation equipment and network control equipment can be completely automatically restored after data transfer is completed.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 2 is a block diagram illustrating one embodiment of a remote typewriter control method according to the present invention.

In FIG. 2, the same parts as those shown in FIG. 1 are given the same reference numerals, and their explanations will be omitted.

A maintenance station network control device 10 is connected to the subscriber line of the maintenance station exchange.
and a maintenance station modem 11 are connected in sequence, and between the maintenance station modem 11 and the typewriter 12, a terminal device ready ( The modem adapter (MDAP) is a means of generating a disconnection signal that misses the ER
) 13 are provided.

FIG. 3 is a block diagram showing the configuration of the modem adapter 13. In Figure 3, 14 is a timer (TIM)
, 15 is an edge-triggered monostable multivibrator (MS), 16 is an inno (INY), 17,1
8 is an and gate (ANDI).

AND2), 19 is a NOR gate (NOR). Note that FIG. 4 shows the maintenance station network control device 10. It is a flowchart of signals between the maintenance station modulation/demodulation device 11 and the typewriter 12.

When the slave station needs to transfer data to the typewriter 12, the slave exchange puts the slave network controller 6 in a calling state and connects to a predetermined subscriber circuit of the maintenance station via hotline connection. Maintenance station network control device 10 for connected typewriters
Performs outgoing connection call processing with . The maintenance station exchange performs general call processing on this call and sends a paging signal to the maintenance station network control device 10. On the other hand, when this network control device 10 receives a paging signal, it sends a paging indication (CI) signal to the modulation/demodulation device 11 (see FIG. 4).

Upon receiving this call indication (CI) signal, the modem 1
1 is a typewriter started up and connected to the modem 11.
It is determined whether or not the terminal device is ready to receive the signal of No. 12 based on the terminal device ready (ER) signal. Since typewriter 12 is powered on and is constantly outputting the ER double signal,
The modem 11 immediately detects the ER multiplied signal, and as a result,
A line connection command (CML) signal is sent to the network control device 10, and a data set ready (DR) signal is sent to the typewriter 12, respectively. Upon receiving this CML signal, the network control device 10 responds by performing a ring trip and connects the subscriber line of the exchange to the modulation/demodulation device 1o. On the other hand, the modem adapter 13, which is a disconnection signal generating means for disconnecting the terminal equipment ready (ER) signal of the typewriter 12 based on the carrier detection signal, is activated by the DR double signal transmitted from the modem 10 to the typewriter 12. be done.

At this point, the change adjustment device 5゜11 of the slave station and maintenance station:
Since signal carrier waves (carriers) have not yet been transmitted to each other, the modulator/demodulator 11 of the maintenance station cannot detect the carrier.
The carrier detect (CD) signal is in a low level state. Here, since the DR double signal is at a high level, the output of the AND gate 17 of the modem adapter 13 becomes a high level, and therefore the timer 14 is activated. This timer 1
4 takes the timing of a predetermined constant time and outputs a pulse of a constant time width at the time of timeout.

This timer 14 is effective when a general call is mistakenly received by the typewriter 12. That is,
After the ring trip, the network controller io#i communication path is switched to the modem 11 and the subscriber circuit is not monitored. Even if a person turns on or hooks the receiver, there is no means to transmit the on-hook information to the network control device 10 or the modulation/demodulation device 11. Then, when the timer 14 of the modem adapter 13 cannot detect the carrier by the modulator/demodulator 5 of the slave station within a certain period of time after receiving the DR signal, K times out, and therefore the output pulse is ANDed for a certain period of time. The logic of the gate 18 could not be determined (because of this), the ER multiplied signal output from the typewriter 12 is cut off for a certain period of time, and this cut-off causes the modem 11 and the network control equipment 10 to be cut off.
will be restored.

On the other hand, in the case of a regular incoming call from the modulation/demodulation device 5 of the slave station, the ring trip of the network control device 10 of the maintenance station causes
When a communication path is formed between the modulation/demodulation device 5 of the slave station and the modulation/demodulation device 11 of the maintenance station, both modulation/demodulation devices 5.11 transmit carriers to each other, so the modulation/demodulation device 11 immediately detects the carrier. A carrier detection (CD) signal is sent to the typewriter 12. Due to this CD signal, in the adapter 13, the logic of the AND gate 17 that starts the timer 14 is no longer valid, and the timer 14 is therefore restored. As a result, data is transferred between both modulators 5.11.

When the data transfer is completed, the modulation/demodulation device 5 of the slave station disconnects the carrier. Next, when the carrier coming from the slave station is cut off, the modem 11 of the maintenance station connects the typewriter 12.
Cut off the CD signal being sent to. In the modem adapter 13, the CD signal is applied to the input of the monostable multivibrator 15 via the inverter 16, so that the C
When D signal is disconnected, monostable multivibrator-1
The input signal 5 changes from low level to high level, thereby activating the monostable multivibrator 15, which outputs a pulse with a constant time width. The pulse signal passes through the NOR gate 19 and applies a low level signal to one input of the AND gate 18, so the logic of the AND gate 18 cannot be established, and therefore the ER multiplied signal is cut off for a certain time width of the pulse. That will happen. As a result, the modem 11 is restored (by disconnecting the ER signal), the CML signal and the DR signal are disconnected, and the network control device 1o is also restored, thereby entering a waiting state for the next incoming call.

In this way, data transfer from the slave exchange to the typewriter 12 can be carried out without requiring any maintenance personnel's operations, and even if an erroneous connection occurs from the general subscriber station, data can be transferred automatically to the typewriter 12. It can be restored.

As explained above, according to the remote typewriter control system according to the present invention, a network control device, a modem, and a typewriter are sequentially connected to a subscriber line of a maintenance station exchange, and the modem and typewriter are - Since the structure includes a means for disconnecting the terminal device ready signal of the typewriter based on the carrier detection signal of this modulation/demodulation device, when a maintenance person manually operates the typewriter, It has the feature of automatically restoring the maintenance station network controller and maintenance station modem.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional typewriter control method, FIG. 2 is a block diagram showing an example of a remote typewriter control method according to the present invention, and FIG. FIG. 4 is a block diagram showing the configuration of a modem adapter used in the same embodiment. FIG. 4 is a flowchart of signals among the maintenance station network control device, the maintenance station modulation/demodulation device, and the typewriter in the same embodiment. 1...Central controller (CC) 2...Speech system control device (SPC) 3...Transfer control device (TC) 4...Slave station call switch (SW) 5...Slave station modulation/demodulation Device (MD) 6...Slave station network control unit (NCU) 7...Outgoing trunk (OCT) 8...Maintenance station channel switch (SW) 9...Incoming trunk (ICT) 10... Maintenance station network control unit (NCU) 11... Maintenance station modem (MD) 12... Typewriter (TTY) 13... Modem adapter (MDAP) 14... Timer (TIM) 15... Monostable multivibrator - 16...Inverter (INV) 17, 18...Ando) (ANDi, AND
2) 19...Noah Gate (NOR) Applicant: NEC Corporation 336

Claims (1)

[Claims] In a system in which a network control device, a modem and a typewriter are sequentially connected to a subscriber circuit of an exchange of a maintenance station located in a remote location, and the typewriter is controlled via a general public line of the exchange, the modem and the moderator are controlled. and said typewriter, further comprising means for disconnecting a terminal device ready signal of said typewriter based on a carrier detection signal of said modulation/demodulation device.