JPH02105638A - In-band signal equipment - Google Patents

Abstract

PURPOSE:To eliminate the need for the selection and the setting of a cable equalizer by detecting signals sent from two oscillators from a transmission side at a reception side, and automatically selecting and setting the cable equalizer optimum for the transmission frequency characteristic of a subscriber line out of plural cable equalizers corresponding to their levels. CONSTITUTION:The controller 8 of a transmission part 1 outputs two output signals with different frequencies from the oscillators 2 and 3 to a transmission circuit 6 by controlling a switch 4 in a no speech state other than in dialing or in busy, and sends them to a subscriber line 9 via a line separator 7. The signal is sent from the subscriber line 9 to a reception part 10, and in the reception part 10, it is inputted to an A/D converter 12 via a line separator 11, and converted to a digital signal. A controller 28 switches the cable equalizers 14-17 sequentially, and stores the level of the signal inputted in respective case. The controller 28 selects the optimum cable equalizer based on a stored signal level afterwards, and sets it as the cable 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 switches and sets two line segmenters 36, 44 and a plurality of cable equalizers 38, 39, 40, 41 that correct the transmission frequency characteristics in the subscriber line. switching terminals 37 and 42 for detecting the ringer and a receiving circuit 4 for detecting the ringer and adjusting the call level.
3.

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, while 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 operator at the receiving section selects the cable equalizer most suitable for the above characteristics and sets it using the 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. Furthermore, even if the cable equalizer is initially set to the optimum value, it is not possible to promptly respond to changes in characteristics due to occasional temperature fluctuations.

An object of the present invention is to eliminate such drawbacks and automatically perform initial setting of a cable equalizer for correcting transmission frequency characteristics in the subscriber line and correction of level fluctuations in the subscriber line due to temperature fluctuations. An object of the present invention is to provide an in-band signaling device.

[Means to solve the problem]

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 the voice band, wherein the transmitting section transmits signals of first and second frequencies. an oscillator that sends a signal to the line, and the receiver includes an A/D that converts the signal from the line into a digital signal.
a converter; a level adjuster that adjusts and outputs the level of the output signal of this A/D converter; and extracts and outputs a signal component of the first frequency included in the output signal of this level adjuster. a first signal extractor; a second signal extractor that extracts and outputs a signal component of the second frequency included in the output signal of the level adjuster; a plurality of cable equalizers; and these cables. a switch that connects an equalizer between the level adjuster and the first and second signal extractors; and a switch that connects the equalizer between the level adjuster and the first and second signal extractors; and a controller that controls and sets the cable equalizer and controls the level setting of the level adjuster.

〔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 transmitting section l and a receiving section 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 transmission circuit 6 for adjusting the call level, a switch 4 for switching between the signals from the oscillators 2 and 3 and the signal from the line disconnector 5, and a controller for controlling the switch 4. 8.

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 an output of the A/D converter. a level adjuster 18 that adjusts the level of the signal, that is, a received input signal; a plurality of cable equalizers 14 to 17 that corrects the transmission frequency characteristics in the subscriber line 9;
and a switch 13 for switching these equalizers,
Furthermore, a signal extractor 22 extracts the frequency component of the signal output by the oscillator 2 from the output signal of the switch 13, a level adjuster 23 adjusts the level of the output signal, and a rectifier 24 rectifies the output signal. , a signal extractor 25 that extracts the frequency component of the signal output by the oscillator 3 from the output signal of the switch 13, a level adjuster 26 that adjusts the level of the output signal, and a rectifier 27 that rectifies the output signal. It includes a controller 28 that controls the switch 13 and the level adjuster 18 based on the output signals of the rectifiers 24 and 27. 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 receives and receives signals from the D/A converter 20. The line disconnector is equipped with a device 21.

Next, the operation will be explained. First, the initial setting of the cable equalizer is performed as follows. That is, the controller 8 of the transmitter 1 controls the switch 4 to switch between two different frequencies from the oscillator 2.3 when there is no call other than dialing or busy.
The two output signals are outputted to the transmitting circuit 6, and the line disconnection is performed by the circuit 7.
The signal is transmitted to the subscriber line 9 through the subscriber line 9.

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.
is input into the system and converted into a digital signal.

The signal is then input to the switch 13 via the level adjuster 18. Controller 28 initially controls switch 13 to select cable equalizer 14, so that the signal from level adjuster 18 passes through cable equalizer 14 to signal extractor 22.25. input. The two frequency components extracted here have their levels adjusted by level adjusters 23 and 26, and then rectified by rectifiers 24 and 27.
It is input to the controller 28. The controller 28 connects these rectifiers 2
4. Store the level of the signal from 27. The controller 28 then controls the switch 13 to select the cable equalizer 15 and stores the level of the signal input from the rectifiers 24 and 27 at that time. The controller 28 also switches over the cable equalizers 16, 17 one after another and stores the level of the input signal in each case. The controller 28 then selects the optimum cable equalizer based on the stored signal level and controls the switch 13 to set that cable equalizer.

The controller 28 also controls the level adjuster 18 based on the level of the signal input from the rectifiers 24, 27, so that even if the level of the signal input to the level adjuster 18 changes due to temperature fluctuations, The level of the signal input to the receiving circuit 19 is always kept constant.

〔Effect of the invention〕

As explained above, the in-band signal device of the present invention detects on the receiving side the signals sent out from the two oscillators from the transmitting side, and selects one of the subscriber lines from a plurality of cable equalizers according to their levels. The optimum transmission frequency characteristics are automatically selected and set. Furthermore, in this in-band signal device, even if the received signal level fluctuates due to temperature fluctuations, the level is automatically adjusted based on the level of the signal from the oscillator. Therefore, there is no need to perform any work to select and set a cable equalizer as in the past, and the level of the received signal input to the receiving circuit does not change even if the temperature changes. .

[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 switching device 6...
Transmission circuit 8.28... Controller 9... Subscriber line 10... Receiving section 12... A/D converters 14 to 17... 1B, 23. 26・ 19・ ・ ・ ・ ・ 20・ ・ ・ ・ ・ 22.25・ ・ ・ 24, 27・ ・ ・ Cable etc. Level adjuster Receiving circuit D/A converter Signal extractor Rectifier

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 level adjuster that adjusts and outputs the level of the output signal of this A/D converter; and extracts and outputs a signal component of the first frequency included in the output signal of this level adjuster. a first signal extractor; a second signal extractor that extracts and outputs a signal component of the second frequency included in the output signal of the level adjuster; a plurality of cable equalizers; and these cables. a switch that connects an equalizer between the level adjuster and the first and second signal extractors; and a switch that connects the equalizer between the level adjuster and the first and second signal extractors; and a controller for controlling and setting the cable equalizer and for controlling the level setting of the level adjuster.