JPH0282843A - Busy display device for common order wire line - Google Patents

Abstract

PURPOSE:To simplify the operation of the user of order wire and to realize the prevention of communication disturbance by other stations during communication with low cost by allowing a network control station to detect the operating state of a common order wire line, superimposing the result of detection on a substantial transmission signal, transmitting the result to all slave stations and displaying it. CONSTITUTION:A detector 6 detects that a demodulator 5 of a network control station 1 receives a transmission wave CH2 from a slave station normally. A detected CH2 operating state signal is superimposed on a transmission signal by a superimposing device 7. A slave station detects the CH2 operating state signal superimposed on a reception signal by a CH2 operating state detector 8, lights a CH2 operating state display device 9 in the case of the operating state to display the busy state. Since the detection of the operating state of the transmission frequency CH2 for the slave station having been implemented individually in each slave station in a conventional system is implemented by the network control station, the busy state of a common order wire line is detected and displayed without incurring a large sized system and high cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention is applicable to a bidirectional common order wire line used in a star communication network in which one network control station has a function of monitoring and controlling all slave stations. The present invention relates to a busy display device.

[Conventional technology]

FIG. 4 is a block diagram showing a conventional star-shaped order wire network. In the figure, 1 is a network control station, 2 and 3 are
is a slave station, 4 is a modulator, and 5 is a demodulator.

Next, we will explain how to use it. The network control station 1 always transmits the network control station exclusive transmission frequency CHI, and the slave station A 2 and slave station B 3 can always listen to the CH1. On the other hand, the slave station transmission frequency CH2 allows only one of all slave stations to transmit.

Here, when a certain slave station requests a call, it is confirmed by the following means that the order wire frequency CH2 is in an empty state. That is, one method is to temporarily set the order wire demodulator to the CH2 frequency, and after confirming that it is empty, set it again to the CHI frequency and transmit CH2. As shown in FIG. 4, this is a method in which two systems of demodulators are prepared, and CHI and CH2 are received simultaneously to confirm whether CH2 is empty.

[Problem to be solved by the invention]

Since the conventional star order wire network is configured as described above, it is necessary to reset the receive frequency of the demodulator in order to check whether the slave station transmission frequency CH2 is empty, and the At the same time.

There was a problem in that there was a high possibility of communication interference occurring due to transmission on the same frequency.

This problem can be solved by providing a demodulator for confirmation only, but this requires an extra demodulator for each slave station, which increases the size and cost of the system. there were.

This invention was made in order to solve the problems of the conventional ones as described above, and it allows all the slave stations to constantly monitor the usage status of the slave station transmission frequency CH2, and also allows multiple stations to use the same 〇H. communication interference caused by simultaneous transmission,
It is an object of the present invention to obtain a busy display device for a common order wire line that can be prevented without increasing costs.

[Means to solve the problem]

The busy display device for a common order wire line according to the present invention detects the usage status of the slave station transmission frequency CH2 at the wire control station, superimposes the signal on the transmission signal of the network control station 1, and sends it to all slave stations. At the same time, the slave station is configured to display the status.

[Effect]

In this invention, with the above-described configuration, the detection of the usage status of the slave station transmission frequency CH2, which was conventionally performed individually in each slave station, is performed centrally at the network control station, so that the system can be improved. Upsizing.

A busy state of a common order wire line can be detected and displayed without increasing costs.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows a busy indicator for a common order wire line according to an embodiment of the present invention, in which the same reference numerals as in FIG. 4 indicate the same parts. 6 is a detector for the usage status of CH2,
7 is a superimposition device for superimposing the usage status of CH2 on the transmission signal of the network control station, and 30 is superimposition sending means consisting of the detector 62 superimposition device 7. Further, 8 is a detector for the superimposed usage state signal of CH2, 9 is an indicator for the usage state of CH2, and 40 is a busy display means consisting of the detector 81 and indicator 9.

In addition, Figure 2 shows the relationship between each station, and in the figure,
IO is the slave station C, and 11 is the slave station.

Furthermore, FIG. 3 shows the frequency relationship in the baseband, where 12 is a transmission frequency CH1 exclusively for the network control station, and 13 is a transmission frequency CH2 for the slave station.

Next, the operation will be explained. The detector 6 detects that the demodulator 5 of the network control station 1 has successfully received the transmission wave CH2 from the slave station.
Detected by The detected CH2 usage state signal is superimposed with the transmission signal in a superimposer 7. This situation is shown in FIG. 5. Like the SS signal 15, the CH2 usage state signal (OW CHBUSY signal) 16 is arranged outside the transmission frequency band, and is turned on/off depending on the usage state of CH2. This situation is shown in FIG.

On the other hand, on the slave station side, the CH2 usage status detector 8 detects the CH2 usage status signal superimposed on the received signal, and if it is in the usage status, the CH2 usage status indicator 9 lights up to indicate that it is in the busy status. let It is also possible to use this signal to prohibit transmission from a slave station in order to prevent erroneous operation, or to send a busy tone to the order wire handset.

In addition, in the above embodiment, a case was explained in which a carrier separate from the SS carrier is provided outside the transmission signal band as a means of transmitting the CH2 usage status, but when operating in an omnibus system, the SS carrier as shown in FIG. It is possible to transmit using the frequency 15 as it is. FIG. 8 shows a time chart in this case.A unique advantage of this embodiment is that the same hardware as the user line can be used, making the system configuration simple and inexpensive.

In addition, in the above embodiment, the CH2 status signal (OWCHBUS
Although the Y signal (Y signal) is shown arranged outside the transmission frequency band like the SS signal, it may also be incorporated into a part of the transmission frame of the network control station as shown in FIG.

FIG. 9 shows a busy display device for a common order wire line according to still another embodiment of the present invention, in which the OW CHBUSY signal is incorporated into a part of the transmission frame of the network control station, and in the figure, FIG. The same reference numerals indicate the same thing.

The relationship among the stations in the apparatus shown in FIG. 9 is as shown in FIG. 2, and the frequency relationship in the baseband is as shown in FIG. 3.

Next, the operation will be explained. The detector 6 detects that the demodulator 5 of the y4 control station l has normally received the received wave CH2 from the slave station. The detected CH2 usage state signal is superimposed on the transmission signal by a superimposer 7. This situation is shown in FIG. CH2 usage status signal (OW CHBUSY
The signal) is incorporated into a part of the transmission frame 17 of the network control station, and is turned on/off depending on the usage status of CH2. This situation is shown in FIG.

On the other hand, on the child station side, a CH2 usage state detector 8 detects the CH2 usage state signal superimposed on the received signal, and when the CH2 usage state signal is in the usage state, the CH2 usage state indicator 9 is turned on. It is also possible to use this signal to prohibit transmission from a slave station to prevent erroneous operation, or to send a busy tone to the order wire handset.

〔Effect of the invention〕

As described above, according to the common order wire line busy display system device according to the present invention, the network control station detects the usage status of the common order wire line, superimposes the detection result on the original transmission signal, and Since the information is transmitted and displayed to the slave station, it is possible to simplify the operation of the order wire user and prevent communication interference by other stations in communication at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a busy display device for a common order wire line according to an embodiment of the present invention, FIG. 2 is a diagram showing the relationship between each station, FIG. 3 is a diagram showing the relationship between order wire frequencies, and FIG. The figure shows a conventional star-shaped order wire circuit.
A block diagram of network A, FIG. 5 is a diagram showing the frequency relationship of status signal transmission of CH2 according to an embodiment of the present invention, FIG. 6 is a time chart diagram showing the operation according to an embodiment of the present invention, and FIG. is a diagram showing the frequency relationship of CH2 status signal transmission according to another embodiment of the invention, FIG. 8 is a time chart diagram showing the operation according to another embodiment of the invention, and FIG. FIG. 10 is a block diagram showing the embodiment, FIG. 10 is an explanatory diagram showing how the usage status signal of CH2 is transmitted according to the embodiment of FIG. 9, and FIG. 11 is a time chart of the operation according to the embodiment of FIG. 9. In the figure, l is a network control station, 2 is a slave station A, 3 is a slave station B,
4 is a modulator, 5 is a demodulator, 6 is a CH2 usage state detector,
7 is a CH2 usage status signal superimposition device, 8 is a CH2 usage status signal detector, 9 is a CH2 usage status indicator, and 10 is a slave station C1.
11 is a slave station, 12 is a transmission frequency CHI dedicated to the network control station,
13 is the slave station transmission frequency CH2, 14 is the transmission signal, 15
is an SS, 16 is an OW CHBUSY signal, 17 is a transmission frame of the cable control station, 30 is a superimposition sending means, and 40 is a busy display means. Note that the same reference numerals in the figures indicate the same or equivalent parts. 0WC1-I BUSY 17:1rJII!Jiff ++5yf!yi-zFigure 11

Claims (1)

[Claims] (1) A device for displaying the usage status of a common order wire line, which is a transmission line for slave stations, in a star communication network in which one network control station monitors and controls all slave stations, a superimposition transmitting means provided in the network control station for detecting the presence or absence of an input signal to the receiver of the network control station and superimposing the detected status signal on a transmission signal and transmitting the superimposed signal; 1. A busy display device for a common order wire line, comprising: busy display means for detecting a status signal of a network control station from a transmission signal sent from a network control station and displaying the signal.