JPH0282746A - In-band signal transmission system - Google Patents

Abstract

PURPOSE:To save labor of a test by sending an oscillating signal from the in-band signal device at a transmitting side through a transmission line and automatically returning the signal with the in-band signal device at a receiving side. CONSTITUTION:At an in-band signal device 3A at a transmitting side, the oscillating signal of an oscillating circuit 33 is supplied through a switch 34 to a transmitting circuit 30 and the transmitting circuit 30 sends the oscillating signal through a coupler 37 to a transmission line 5. An in-band signal device 3B at a receiving side inputs this sent signal to a receiving circuit 31 and a transmitting control circuit 35, the transmitting control circuit 35, when it is detected that the signal is an oscillating signal, adds a constant identifier to the oscillating signal and sends it to the coupler 37, and the coupler 37 returns the signal through the transmission line 5 to the in-band signal device 3A at the transmitting side. Consequently, one person can execute the test in order to test in-band signal devices 3A and 3B. Thus, the labor of the test can be saved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an in-band signal transmission system in which in-band signal devices are connected facing each other via a transmission path, and particularly relates to an in-band signal transmission system in which in-band signal devices are connected to each other via a transmission path, and in particular, transmit signals by remote control during testing. This invention relates to an in-band signal transmission system that saves testing labor by folding back signals.

[Conventional technology]

Conventionally, this type of in-band signal transmission system uses an in-band signal device that includes a transmitting circuit that can send out a voice band signal of a frequency within the voice band, and a receiving circuit that can receive the voice band signal from a transmission path. They are connected to face each other via a transmission path. In such an in-band signal transmission system, the in-band signal device is subjected to a dial pulse transmission test,
When performing tests such as level diagram confirmation, operations at both opposing stations are required. Therefore, at least one person had to be assigned to both stations to conduct the aforementioned tests.

On the other hand, some devices have been installed with a loopback function, but since this loopback is performed on the transmission line side, level equalization has not been achieved. There is also a band white signal device with a level equalization function, but the purpose of this loopback function (transmission line side, terminal side) was not clear.

[Problem to be solved by the invention]

If the in-band signal device of the above-mentioned in-band signal transmission system is not provided with a loopback function, an operation is required on the receiving side, which has the disadvantage that efficient testing cannot be performed.

Additionally, if the in-band signal device of the above-mentioned in-band signal transmission system is equipped with a loopback function, the callback is performed within the opposing station, so it can be determined whether it is a device failure or a transmission line failure. The disadvantage is that it does not stick. Also,
Similarly, if an in-band signal device is equipped with a loopback function, the frequency of the voice band signal is used.
For PBXs, this has the disadvantage of causing erroneous connections and hold times, and for terminal equipment, it temporarily activates the bell.

The present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide an in-band signal transmission system that has a simple configuration and saves labor in testing.

[Means to solve the problem]

In order to achieve the above-mentioned object, an in-band signal transmission system of the present invention includes a transmitting circuit capable of transmitting a voice band signal having a frequency within the voice band, and a receiving circuit capable of receiving a voice band signal from a transmission path. In an in-band signal transmission system in which two in-band signal devices are connected facing each other via a transmission path, the in-band signal device includes an oscillation circuit that oscillates at a frequency different from that of the audio band signal, and an A switch that inputs the oscillation signal to the transmission circuit, a transmission control circuit that detects the oscillation signal sent via transmission, attaches a certain identifier and sends it again, and inputs the signal from the transmission circuit and the transmission control circuit. This configuration includes a coupler that combines the signals and sends them out to a transmission path.

According to the in-band signal transmission system of the present invention, the in-band signal device on the transmitting side supplies the oscillation signal of the oscillation circuit to the transmitting circuit via the switch. Thereby, the transmitting circuit sends out the oscillation signal to the transmission path via the coupler. The in-band signal device on the receiving side inputs the signal sent from the transmission path to the receiving circuit and the transmission control circuit. When the transmission control circuit detects that this signal is an oscillation signal, it adds a certain identifier to the oscillation signal and sends it to the combiner. The coupler is
This signal is sent back to the in-band signaling device on the transmitting side via a transmission path. Accordingly, according to the present invention, a test of an in-band signal device can be performed by one person, thereby saving labor in the test. Further, according to the present invention, the transmission control circuit may have a simple circuit configuration.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the in-band signal transmission system of the present invention. In this FIG. 1, an in-band signal transmission system 1 includes an in-band signal device 3A connected to a terminal T A
It is configured to be connected to the in-band signal device 3B by BI RBA, transmission line 5, and terminal RA-B ITBA.

The in-band signal device 3A has a terminal 4WS.

A terminal device 7A is connected via 4WR. Also,
A terminal device 7B is connected to the in-band signal device 3B via terminals 4WS and 4WR.

The in-band signal device 3A has the same configuration as the in-band signal device 3B. Therefore, the same reference numerals are given to the same components in the in-band signal device 3A and the in-band signal device 3B.

The in-band signal device 3A includes a transmitting circuit 3o that can send out a voice band signal with a frequency within the voice band, a receiving circuit 31, 32 that can receive the voice band signal from the transmission path 5, and a transmitter circuit 3o that can send out a voice band signal with a frequency within the voice band. An oscillation circuit 33 that inputs the oscillation signal from the oscillation circuit 33 to the transmission circuit 30, a switch 34 that detects the oscillation signal sent through the transmission line 5, attaches a certain identifier, and sends it out again. transmission control circuit 35, transmission circuit 30 and transmission control circuit 35
It is configured to include a coupler 37 that takes in signals from through a matching circuit 36, combines them, and sends them out to the transmission line 5.

The transmission control circuit 35 includes a bandpass filter 350, a rectifier circuit 351, and an impedance matching resistor 352.
, waveform correction capacitor 353, and reference voltage setting circuit 3
54, comparator 355, and folding amplifier 356
, a switch circuit 357 , a setting switch 358 for attaching a certain identifier, and a display 359 for displaying the state of the comparator 355 . In the transmission control circuit 35 , only the oscillation signal from the signal from the transmission path 5 is passed through the bandpass filter 350 and the rectifier circuit 35
The signal rectified by 1 is passed through impedance matching resistor 3
The signal is supplied to a comparator 355 via 52. The reference voltage setting circuit 354 includes resistors Ra, R
The reference voltage formed in step b is supplied,
Also, the rectified signal is now manually input. The comparator 355 outputs a signal when the rectified signal is greater than the reference voltage, and switches the switch circuit 357 from the receiving side to the transmitting side. In addition, the comparator 355
The output is displayed by an indicator 359 consisting of a resistor Re and a light emitting diode LED. When the switch circuit 357 is switched, the folding amplifier 3
The circuit is configured such that the output signal from 56 is supplied to a setting switch 358, where an identifier is added, and the output signal is supplied to the coupler 37 via the matching circuit 36.

Next, the operation of the embodiment configured as described above will be explained.

In the in-band signal device 3A on the transmitting side, the oscillation signal of the oscillation circuit 33 is supplied to the transmitting circuit 30 via the switch 34.

As a result, the transmitting circuit 30 transmits the oscillation signal to the matching circuit 36.
The signal is sent to the transmission line 5 via the optical coupler 37.

The oscillation signal transmitted through the transmission line 5 in this way is
The signal is supplied to the in-band signal device 3B on the receiving side. The receiving-side in-band signal device 3B inputs the signal sent from the transmission path 5 to the receiving circuit 31 and the transmission control circuit 35.

The transmission control circuit 35 allows only the oscillation signal from the signal from the transmission path 5 to pass through a band pass filter 350 and rectifies it in a rectifier circuit 351 . The signal rectified by this rectifier circuit 351 is supplied to a comparator 355 via an impedance matching resistor 352. Resistance Ra.

The reference voltage from the reference voltage setting circuit 354 made up of Rb is supplied to a comparator 355 and compared with the rectified signal. Comparator 355 outputs an output signal to switch switch circuit 357 from the receiving side to the transmitting side when the rectified signal is larger than the reference voltage. In addition, the output of the comparator 355 is connected to the resistor Rc and the light emitting diode L.
A display 359 consisting of an ED emits light to display the light. When the switch circuit 357 is switched, the oscillation signal from the transmission line 5 is amplified by the folding amplifier 356 and then supplied to the setting switch 358. The setting switch 358 adds an identifier such as a master station or a slave station to the amplified oscillation signal in advance and supplies the amplified oscillation signal to the coupler 37 via the matching circuit 36. As a result, the coupler 3 of the in-band signal device 3B on the receiving side
7, the signal is looped back and transmitted to the in-band signal device 3A on the transmitting side via the transmission path 5.

Therefore, according to this embodiment, a test of an in-band signal device can be performed by one person, thereby saving labor in the test. Further, according to this embodiment, the transmission control circuit may have a simple circuit configuration.

〔Effect of the invention〕

As explained above, the present invention has a configuration in which an oscillation signal is sent from the in-band signal device on the transmitting side via a transmission path, and this is automatically looped back by the in-band signal device on the receiving side.
During the test, only the transmitting side needs to be operated, which saves labor and allows efficient testing.

Further, the present invention has the advantage that the circuit configuration is simple, and the number of parts and assembly steps can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1... In-band signal transmission system, 3A, 3B.
...In-band signal device, 5...Transmission line, 3
0...Transmission circuit, 31.32...Reception circuit, 35...Transmission control circuit.

Claims (1)

[Claims] An in-band signal device comprising a transmitting circuit capable of transmitting a voice band signal of a frequency within the voice band and a receiving circuit capable of receiving a voice band signal from a transmission line is connected to face each other via a transmission line. In the in-band signal transmission system, the in-band signal device includes an oscillation circuit that oscillates at a frequency different from that of the voice band signal, a switch that inputs the oscillation signal from the oscillation circuit to the transmission circuit, and a switch that inputs the oscillation signal from the oscillation circuit to the transmission circuit, and a It includes a transmission control circuit that can detect the sent oscillation signal, attach a certain identifier and send it out again, and a coupler that combines the signals from the transmission circuit and the transmission control circuit and sends it out to the transmission path. An in-band signal transmission system characterized by: