JPH05176350A - Status responding device - Google Patents

Abstract

PURPOSE:To minimize a wave stopping time by quickly detecting a fault generating position when a fault is generated in a transmission network of a CATV system. CONSTITUTION:A status responding device fixed to an optional position on the transmission network of the CATV system reads out status checking data from a signal outputted from each CATV center. At the time of checking that the status checking data are data to an address set up in an address setting circuit part 6, a signal processing part 5 outputs response data. A fault status from the device 20 by the CATV center. response status from the device 20 by the CATV center.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a status response device for finding a fault occurrence point in a transmission network of a CATV system.

[0002]

2. Description of the Related Art FIG. 3 shows an outline of an urban type cable television (hereinafter referred to as "CATV") transmission network which has been rapidly prevailing in recent years, and 31 is a briger gate control unit (hereinafter (It is called "BGC unit")
Is a main line amplifier, 32 is a tap-off for extracting a signal from the CATV line, 33 is a home device, 34 is an extension amplifier, 35 is a non-reflective terminator, and 36 is a coaxial cable.

In the conventional example thus constructed, C
The trunk amplifier 31 connected in many stages on the trunk of the transmission network of the ATV system corrects the signal level attenuated by the coaxial cable 36, and the BGC unit of each trunk amplifier 31 is CA.
It outputs its own status to the CATV center in response to a request from the TV center.

By the way, a failure occurs in the main amplifier 31 and the coaxial cable 36 in the middle of the transmission network of the CATV system,
When the transmission network ahead of the fault occurrence point stops or the signal quality deteriorates, the main amplifier 31 installed in the transmission network beyond the fault occurrence point gives a status corresponding to the fault condition CA.
It is input to the TV center.

Therefore, if the status input from each main amplifier 31 is monitored at the CATV center,
The location of failure can be found early.

[0006]

[Problems to be Solved by the Invention] However, urban CA
In the transmission network of the TV system, as the scale of the CATV system increases, the branch line branched from the main line becomes longer. Therefore, the fault occurrence point can be found only by the main amplifier 31 installed on the main line of the transmission network of the CATV system. However, there is a problem that it takes time to restore the location where the failure occurred.

The present invention has been made in order to solve such a problem, and can be installed in an arbitrary place of a transmission network of a CATV system, so that a failure occurrence point can be found more quickly. The purpose is to provide a device.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a signal input / output unit for inputting / outputting a modulated signal, a filter for reading status confirmation data from a signal modulated and output at the center of a CATV, and a status confirmation data. A demodulation unit for demodulating the data, an address setting circuit unit in which one of the addresses registered in the center of the CATV is set as a self address, read status confirmation data, and a self address of the address setting circuit unit. Compare
When it confirms that the status confirmation data is the status confirmation data addressed to itself, the signal processing unit that outputs the response data, the modulation unit that modulates the response data, and the filter that outputs by limiting the band of the modulated response data. It consists of

[0009]

According to the present invention, it becomes possible to quickly find a failure occurrence point in the transmission network of the CATV system, so that it takes no time to restore the failure occurrence point and the time of the wave stop is shortened.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows the configuration of the status response device 20 of the present invention. The signal input from the CATV signal tap-off 22 to the signal input / output unit 1 and demultiplexed by the branching unit 2 is shown. From this, the status confirmation data is read by the filter 3 and demodulated by the demodulation unit 4. And
The signal processing unit 5 stores the self-address preset in the address setting circuit unit 6 and the demodulated status confirmation data.
When it is confirmed that the status confirmation data is the status confirmation data addressed to itself, the signal processing unit 5
Outputs response data. Then, the response data output from the signal processing unit 5 is modulated into an upstream signal by the modulating unit 7, the band thereof is limited by the filter 8, and amplified by the amplifying unit 9, and further passes through the branching unit 2 to output the signal. It is output from the input / output unit 1.

FIG. 2 shows a transmission network of a CATV system provided with the status response device 20 of the present invention.
A status response device installed at an arbitrary position in the transmission network of the ATV system, 21 is a main amplifier, 22 is tap-off which is a signal take-out port from the line to the home, and status response device 20 is connected to arbitrary tap-off 22. ing. Reference numeral 23 is a home device, 24 is an extension amplifier, 25 is a non-reflective terminator, and 26 is a coaxial cable.

In such a transmission network of the CATV system, the address setting circuit section 6 of each status response device 20.
All the addresses set in step 1 are registered in the CATV center in advance. When the status confirmation data addressed to each status response device 20 is sequentially output from the CATV center, each status response device 20 outputs the response data when the status verification data addressed to itself is input.

Therefore, if the response data input from each status response device 20 is monitored at the CATV center, it is possible to quickly find a failure occurrence point in the transmission network of the CATV system.

Further, by monitoring the status input from each main line amplifier 21 at the center of the CATV and finding the location of the failure, the CATV is also detected.
It is possible to more finely find a failure occurrence point in the transmission network of the system.

[0016]

As described above, according to the present invention,
By installing the status response device at any place in the CATV system transmission network, it becomes possible to quickly find the location of the failure in the CATV system transmission network. This has the effect of shortening the time.

[Brief description of drawings]

FIG. 1 is a block diagram of a status response device of the present invention.

FIG. 2 is a CAT provided with the status response device of the present invention.
It is a schematic diagram of a transmission network of the V system.

FIG. 3 is a schematic diagram of a transmission network of a conventional CATV system.

[Explanation of symbols]

1 ... Signal input / output unit, 3, 8 ... Filter, 4 ... Demodulation unit, 5 ... Signal processing unit, 6 ... Address setting circuit unit, 7
… Modulator, 20… Status response device.

Claims (1)

[Claims] 1. A signal input / output unit for inputting and outputting a modulated signal, a filter for reading status confirmation data from a signal modulated and output at the center of a CATV, and a demodulation unit for demodulating the status confirmation data. An address setting circuit unit in which one of the addresses registered in the center of the CATV is set as a self address is compared with the read status confirmation data and the self address of the address setting circuit unit. When confirming that the status confirmation data is status confirmation data addressed to itself, a signal processing unit that outputs response data, a modulation unit that modulates the response data, and a band of the modulated response data is limited. A status response device comprising a filter for outputting.