JPH02105637A - In-band signal equipment - Google Patents

Abstract

PURPOSE:To eliminate the need for the selection and the setting of a cable equalizer by detecting two signals with different frequencies sent from a transmission side at a reception side, and automatically selecting and setting the cable equalizer optimum for the transmission characteristic of a subscriber line out of plural cable equalizers corresponding to level difference between them. CONSTITUTION:When an operator performs a prescribed operation on the indicator 81 of a transmission part 1, a controller 8 makes a switch 4 output two output signals with different frequencies from oscillators 2 and 3 to a transmission circuit 6 by applying control, and sends them to the subscriber line 9 via a line separator 7. The signal is sent from subscriber line 9 to a reception part 10, and it is inputted to an A/D converter 12 in a reception part 10 via a line separator 11, then, it is converted to a digital signal. A controller 304 switches the cable equalizers 14-17 sequentially, and stores comprison results from comparators 300 and 302 in respective case. The controller 304 selects the cable equalizer in which the level difference of the two signals with different frequencies from the oscillators 2 and 3 can be minimized, and sets the equalizer by controlling a switch 13.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an in-band signal device for transmitting and receiving a ringer in a dedicated line, and in particular to a cable equalizer for correcting transmission frequency characteristics in a subscriber line. The present invention relates to an in-band signal device that automatically performs initial setting and correction of level fluctuations in subscriber lines due to temperature fluctuations.

[Conventional technology]

FIG. 2 shows an example of a conventional in-band signal device.

This device is composed of a transmitting section 30 and a receiving section 35, which are connected to each other by a subscriber line 34.

The transmitter 30 then connects the two line disconnectors 31 and 33.
and a transmitting circuit 32 for sending out a ringer and adjusting the speech level.

On the other hand, the receiving unit 35 has two line components 36 and 44,
A plurality of cable equalizers 38, 39, 40, 41 for correcting the transmission frequency characteristics in the subscriber line, a switching terminal 37, 42 for switching and setting these, detecting the ringer, and adjusting the speech level. Receiving circuit 43 for
It is composed of.

In this in-band signal device, the cable equalizer is set as follows. The operator of the transmitter 30 prepares an oscillator and connects the line disconnector to the receiver 33, and the operator of the receiver 35 prepares a level meter and connects the line disconnector to the receiver 36. Then, the operator at the transmitter side keeps the output level of the oscillator constant and changes the output frequency. At this time, the operator at the receiving section reads the level meter and measures the transmission frequency characteristics of the subscriber line. Based on the results, the receiver side operator selects the cable equalizer most suitable for the above characteristics,
Set by switching terminals 37 and 42.

[Problem to be solved by the invention]

In the above-mentioned conventional in-band signal equipment, an oscillator and a level meter must be prepared to set up the cable equalizer, and workers must be on standby at the transmitting and receiving sides to operate the oscillators. , reading level meters, and selecting and setting cable equalizers.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such drawbacks and to provide an in-band signal device that automatically selects and sets a cable equalizer for correcting transmission frequency characteristics in a subscriber line.

Means for Solving Problem C] The present invention provides an in-band signal device that includes a transmitting section and a receiving section connected by a line and performs ringer transmission and reception using a voice band, wherein the transmitting section comprises: The receiver includes an oscillator that sends signals of first and second frequencies to the line, and the receiver includes an A/D converter that converts the signal from the line into a digital signal.
a converter; a first signal extractor that extracts and outputs a signal component of the first frequency included in the output signal of the A/D converter; and an output signal level of the first signal extractor. a first comparator that compares the voltage with a predetermined voltage; a second signal extractor that extracts and outputs a signal component of the second frequency included in the output signal of the A/D converter; a second comparator that compares the output signal level of the second signal extractor with a predetermined voltage, a plurality of cable equalizers, and these cable equalizers are connected to the A/D converter and the first and second a switch connected between the second signal extractor and the second signal extractor; and a controller that controls the switch and sets the cable equalizer based on the comparison results of the first and second comparators. It is characterized by:

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram illustrating an embodiment of an in-band signaling device according to the present invention. This device includes a transmitter 1 and a receiver 10.
These are connected to each other by a subscriber line 9.

The transmitter 1 includes two line separators 5 and 7, and a ringer oscillator 2, which generates signals with different frequencies.
3, a transmitting circuit 6 for adjusting the speech level, a switching device 4 for switching between the signal from the oscillator 2.3 and the signal from the line disconnector 5, and a cable equalizer on the receiving side. It is composed of an indicator 81 for starting automatic setting and a controller 8 for controlling the switch 4.

On the other hand, the receiving section 10 includes a line disconnector 11, an A/D converter 12 that converts an analog signal received through the line disconnector 11 into a digital signal, and a transmission frequency characteristic in the subscriber line 9. It is provided with a plurality of cable equalizers 14 to 17 for correcting and a switch 13 for switching these equalizers, and further extracts the frequency component of the signal output from the oscillator 2 from the output signal of the switch 13. A signal extractor 22, a level adjuster 23 that adjusts the level of its output signal, a rectifier 24 that rectifies its output signal, a reference voltage generator 301 that generates a reference voltage, and the output voltage of the rectifier 24 and the reference voltage. A comparator 300 that compares the output voltage of the generator 301, a signal extractor 25 that extracts the frequency component of the signal output from the oscillator 3 from the output signal of the switch 13, and a level adjustment that adjusts the level of the output signal. a rectifier 27 that rectifies its output signal, a reference voltage generator 303 that generates a reference voltage, a comparator 302 that compares the output voltage of the rectifier 24 and the output voltage of the reference voltage generator 303; A controller 3 that selects a vase such as a cable based on the comparison results of the containers 300 and 302 and controls the switch 13.
04. The receiving unit 10 further includes a receiving circuit 19 that adjusts the call level on the receiving side, a D/A converter 20 that converts the output signal into an analog signal, and a D/A converter 20 that converts the output signal into an analog signal.
The line disconnector 21 receives and takes signals from the A converter 20.

Next, the operation will be explained. Automatic setting of the cable equalizer is performed as follows. That is, when the operator performs a predetermined operation on the indicator 81 of the transmitter 1, the indicator starts automatic setting of the cable equalizer. As a result, the controller 8
controls the switching device 4 to output the two output signals of different frequencies from the oscillator 2.3 to the transmitting circuit 6, and sends out the line to the subscriber line 9 through the circuit 7.

This signal is sent from the subscriber line 9 to the receiving section 10, and in the receiving section 10, the line is disconnected by an A/D converter 12 through a device 11.
and converted into digital signals.

The controller 304 initially controls the switch 13 to select the cable equalizer 14, and as a result, the A/
The signal from the D converter 12 passes through the cable equalizer 14 and is input to the signal extractor 22.25. The two frequency components extracted here have their levels adjusted by level adjusters 23.26, rectified by rectifiers 24.27, and then input to comparators 300 and 302, respectively. And the comparators 300 and 302 are connected to the rectifiers 24 and 27, respectively.
The voltage from the reference voltage generators 301 and 303 are compared, and the result is output to the controller 304. Controller 3
04 stores the comparison results from these comparators 300 and 302. Controller 304 then controls switch 13 to select cable equalizer 15, which then selects comparator 300.
The comparison result input from 302 is stored. Controller 30
4 further switches to cable equalizers 16 and 17 sequentially,
The comparison results from the comparators 300 and 302 in each case are stored. The controller 304 then selects the cable equalizer that minimizes the level difference between the two signals of different frequencies from the oscillator 2.3 based on the stored comparison results, and controls the switch 13 to select the cable equalizer that minimizes the level difference between the two signals of different frequencies from the oscillator 2. Set up a vase.

〔Effect of the invention〕

As explained above, the in-band signal device of the present invention detects, on the receiving side, two signals with different frequencies sent out from two oscillators from the transmitting side, and uses a plurality of cable equalizers according to the level difference between them. The system automatically selects and sets the most suitable one for the transmission frequency characteristics of the subscriber line. Therefore, with this in-band signal device, there is no need to perform any work for selecting and setting a cable equalizer as in the prior art.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an in-band signaling device according to the present invention, and FIG. 2 is a block diagram showing an example of a conventional in-band signaling device. 1... Transmitter 2.3... Oscillator 4.13... Switcher 5, 7.11.21... Line disconnector 6... Transmission circuit 8.304... Controller 9... Subscriber line 10... Receiving section 12... A/D converters 14 to 17... Cable equalizer 19... Receiving circuit 20. ...D/A converter 22, 25...signal extractor 23.26...24. 27・ ・ 81・ ・ ・ 300.302・ 301.303・ Level adjuster Rectifier Indicator Comparator Reference voltage generator

Claims (1)

[Claims] (1) In an in-band signal device that includes a transmitter and a receiver connected by a line and performs ringer transmission and reception using a voice band, the transmitter transmits signals of first and second frequencies to the The receiver includes an oscillator that sends out signals to a line, and the receiver includes an A/D converter that converts signals from the line into digital signals.
a converter; a first signal extractor that extracts and outputs a signal component of the first frequency included in the output signal of the A/D converter; and an output signal level of the first signal extractor. a first comparator that compares the voltage with a predetermined voltage; a second signal extractor that extracts and outputs a signal component of the second frequency included in the output signal of the A/D converter; a second comparator that compares the output signal level of the second signal extractor with a predetermined voltage, a plurality of cable equalizers, and these cable equalizers are connected to the A/D converter and the first and second a switch connected between the second signal extractor and the second signal extractor; and a controller that controls the switch and sets the cable equalizer based on the comparison results of the first and second comparators. An in-band signal device characterized by: