JPH11164277A - Status monitor for catv amplifier and catv amplifier using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a center side to remotely supervise whether or not status monitor is in normal operation and to simplify testing at the time of installation of a new system or of a system updating. SOLUTION: This status monitor is provided with a data MODEM circuit 2 built in a CATV amplifier 1 to demodulate a polling signal from a center and to modulate a reply signal to a center, and with a controller circuit 3 that controls and diagnoses the amplifier 1 based on the demodulated polling signal and outputs a reply signal in response to the polling signal, and further with a detection circuit 4 that detects the polling signal from the center side to the data MODEM circuit 2 to detect its signal level. The controller circuit 3 has a presence discrimination function that discriminates the presence of the polling signal based on a detection signal of the detection circuit 4, and a fault discrimination function that diagnoses contents of a polling signal demodulated by the data MODEM circuit 2 to discriminate the normally of the polling signal as well as a self-diagnostic function that executes self- diagnosis of a status monitor unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a status monitor of an amplifier used in a CATV system, and can easily confirm whether a status monitor for controlling and diagnosing an amplifier is normally functioning itself. Is to do so.

[0002]

2. Description of the Related Art A status monitor (status monitor unit) is built in an amplifier connected to a relay transmission network of a CATV system. The status monitor plays an important role for remotely controlling the amplifier connected to the transmission network from the center and for remotely monitoring the state of the amplifier. The status monitor is activated when called by a polling signal transmitted from the center, and performs various operations based on instructions from the center included in the signal. For example, it adjusts the gain of the amplifier or diagnoses whether the circuits of each part of the amplifier are functioning properly. When a diagnosis or the like is performed, the result can be transmitted to the center.

[0003] The status monitor remotely diagnoses the amplifier in accordance with a command from the center. The status monitor itself is diagnosed as follows. That is, FIG.
As shown in (1), a measuring instrument 10 such as a spectrum analyzer is connected to the status monitor 6 of the amplifier 1 in a state where the amplifier 1 is attached to the relay transmission network 7, and in that state, a polling signal from the center is received. Appropriate operation is performed according to the contents of the polling signal, whether the reception level is appropriate, whether the received data of the polling signal has no error, whether the response signal can be transmitted, whether the frequency of the response signal is appropriate, or not. Inspection items such as whether or not the inspection has been performed have been examined in detail by the measuring instrument 10.

[0004]

In the test of the status monitor 6 as shown in FIG. 2, each time a CATV system is newly established or changed, the status is measured one by one while being connected to the relay transmission network. Since the process is performed by connecting devices, a great deal of time and cost are required, and this improvement has been desired.

[0005]

A status monitor of a CATV amplifier according to the first aspect of the present invention is built in a CATV amplifier, as shown in FIG. 1, and receives a polling signal from a center and demodulates it. And a data modem circuit 2 for modulating and transmitting a response signal to the center with respect to the polling signal, controlling and diagnosing the amplifier 1 based on the demodulated polling signal, and responding to the polling signal. A status monitor provided with a controller circuit 3 capable of also outputting a signal, comprising a detection circuit 4 for detecting a polling signal input from the center side to the data modem circuit 2 and detecting a signal level thereof; Is a function for determining the presence or absence of a polling signal based on the detection signal of the detection circuit 4; And distinguishable abnormality determination function of the normal or abnormal polling signal to diagnose the contents of the polling signal demodulated by 2, in which and a viable self diagnosis function self-diagnosis of the status monitor unit.

According to the status monitor of the CATV amplifier according to the present invention, when an abnormality is detected by any one or more of the presence / absence determination function, abnormality determination function, and self-diagnosis function of the controller circuit 3, The data modem 2 can transmit a signal to notify the abnormality to the center regardless of the presence or absence of the call by the polling signal from the center or when the data modem 2 is called by the polling signal.

According to a third aspect of the present invention, a CATV amplifier is provided with a status monitor according to the first or second aspect, as shown in FIG. The apparatus includes a display unit 5 for externally displaying a result of diagnosis by any one or more of the presence / absence determination function, abnormality determination function, and self-diagnosis function.

[0008]

FIG. 1 is a schematic diagram showing an embodiment of a status monitor and a CATV amplifier incorporating the status monitor according to the present invention. The CATV amplifier 1 of FIG. 1 has a built-in bidirectional amplifying unit (AMP unit) 8, and transmits a downlink signal transmitted from a center to a terminal through a relay transmission network 7 and a relay transmission network 7 from a terminal to the center. And an uplink signal transmitted through the relay can be relay-amplified with an appropriate gain. The AMP unit 8 is basically the same as that of an existing bidirectional amplifier, and includes a circuit for amplifying a signal, a circuit for adjusting a gain, a gate circuit for passing and blocking an upstream signal, and the like. . The AMP unit 8 also includes an interface circuit (provided with an A / D converter, not shown) for exchanging information and signals with the controller circuit 3 of the status monitor 6 described later. Built-in. Information inside the AMP unit 8 is output to the controller circuit 3 through the interface circuit, and the control of the AMP unit 8 by the controller circuit 3 is performed through the interface circuit. That is, A
Desired information (information on gain, etc.) in the MP unit 8 can be read out by the status monitor 6, and the AMP unit 8 is appropriately controlled by the status monitor 6 (gain control, ON / OFF of an upstream signal, etc.). ) Can be.

The CATV amplifier 1 has a built-in status monitor (status monitor unit) 6 including a data modem circuit 2, a detection circuit 4, and a controller circuit 3. The data modem circuit 2 is a circuit that modulates and demodulates a signal. The data modem circuit 2 demodulates a polling signal from the signal branched by the branching unit 9 and converts information (address information and command information) included in the polling signal into a controller circuit at a subsequent stage. 3 and modulates a signal (such as a response signal to a polling signal) input from the controller circuit 3 and outputs the response signal to the relay transmission network 7 on the center side via the branching device 9. The detection circuit 4 detects a polling signal on the center side from the signal branched by the splitter 9 and obtains a detection voltage corresponding to the signal level of the polling signal. In this case, the detection voltage is shown in the drawing. The signal is converted into a digital signal through an A / D converter and output to the controller circuit 3. The controller circuit 3 is a so-called microcomputer composed of a CPU, a memory, and the like (both are not shown). A software program is recorded in the memory, and the software program is executed by the CPU. . The controller circuit 3 can communicate with the data modem circuit 2, the detection circuit 4, and the AMP unit 8 connected to the circuit 3, and when receiving a command (polling signal) from the center through the data modem circuit 2, the controller circuit 3 receives the command. Various processing based on the software program is performed based on the command.
For example, processing such as gain control of the AMP unit 8, diagnosis of the operation state of the AMP unit 8, opening and closing of an up gate, and the like are performed. In the present invention, a function of diagnosing the status monitor 6 itself is added to the controller circuit 3, that is,
A software program for diagnosing the status monitor 6 itself is recorded in the memory of the controller circuit 3. Hereinafter, this function, that is, the software program will be described.

The present invention includes three software programs described below. . Numerical information on the reception level of the polling signal detected by the detection circuit 4 and processed by an A / D converter (not shown) is compared with a predetermined reference value to determine whether the polling signal is at an appropriate level or not. Software program to determine whether . A software program for examining the contents of the polling signal demodulated by the data modem circuit 2 to determine whether the signal has an abnormality. Various algorithms can be used to determine whether the signal is normal or abnormal. For example, an algorithm corresponding to an error check function of a modem connected to a telephone line or the like can be used. In addition to this, it is also possible to have information on a polling signal as data in a program, and determine that the polling signal is abnormal when information that is impossible as a polling signal is mixed. . A function for performing self-diagnosis of the status monitor 6. With respect to the data modem circuit 2, the detection circuit 4, and the controller circuit 3 which constitute the status monitor 6, a check is made for a disconnection or a wiring error of the circuit, or a diagnosis is made as to whether or not communication between the circuits is performed normally.

The controller circuit 3 is the same as the controller circuit 3 described above.
When any abnormality is detected by one of the diagnostic programs, it can be transmitted to the center through the data modem circuit 2. This transmission can be performed by the controller 3 by its own judgment even without calling by a polling signal from the center. The signal transmission to the center can be turned on / off by a switch (not shown). If the signal is turned off, the status monitor 6 can transmit a signal to the center only at the time of calling by a polling signal. The self-diagnosis function (three) of the status monitor 6 can output a diagnosis result to a monitor terminal (not shown) provided separately in the amplifier by switching a switch (not shown). Specifically, a dedicated device can be connected to the monitor terminal to diagnose the status of the status monitor 6.

The CATV amplifier 1 is provided with a display (LED) 5 as shown in FIG. 1. The display 5 is designed so that the lighting state can be easily seen from outside the case of the amplifier. is there. The display 5 is configured such that ON / OFF or a lighting color is changed according to a diagnosis result of the diagnosis program (the above three) of the controller circuit 3. It is preferable to provide an independent display 5 for each self-diagnosis function of the status monitor 6, and in this case, it is preferable to provide three displays. In this way, the abnormal part can be easily determined from the lighting pattern of the display 5.

In the embodiment described above, the diagnostic functions (three) related to the status monitor 6 are realized by a software program recorded in a memory (not shown) of the controller circuit 3, but these functions are implemented by hardware. It is also possible to do it.

[0014]

According to the status monitor of the CATV amplifier of the present invention, the following effects can be obtained. 1. The center can remotely monitor whether or not the status monitor 6 is functioning normally, thereby simplifying a test operation when a new system is installed or updated. As a result, costs can be reduced. 2. Status monitor 6 periodically during system operation
Can be diagnosed, it is also possible to foresee a failure of the status monitor 6 and take measures before a major accident occurs. 3. When the status monitor 6 has an abnormality, it can be automatically notified to the center.
Can be prevented from being overlooked. The CATV amplifier according to the present invention has the following effects. 1. It is possible to confirm whether or not the status monitor 6 is functioning normally only by a simple visual inspection of the amplifier, and the inspection and maintenance can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram of a status monitor of a CATV amplifier according to the present invention.

FIG. 2 is a block diagram showing a conventional CATV amplifier and a diagnostic method of a status monitor thereof.

[Explanation of symbols]

 1 CATV amplifier 2 Data modem circuit 3 Controller circuit 4 Detection circuit 5 Display 6 Status monitor

Claims (3)

[Claims] A data modem circuit (1) built in a CATV amplifier (1) for receiving and demodulating a polling signal from a center, and for modulating and transmitting a response signal to the center in response to a polling signal. 2) and a status monitor including a controller circuit (3) capable of controlling and diagnosing the amplifier (1) based on the demodulated polling signal and outputting a response signal to the polling signal. A detection circuit (4) for detecting a polling signal input to the data modem circuit (2) and detecting a signal level of the polling signal is provided, and the controller circuit (3) is provided based on the detection signal of the detection circuit (4). A polling signal, which is capable of determining the presence or absence of a polling signal, and diagnosing the contents of the polling signal demodulated by the data modem circuit (2). CATV, characterized in that it comprises a discernable abnormality determination function of the normal or abnormal, and a viable self-diagnosis function self-diagnosis of the status monitor unit
Status monitor for amplifier. 2. When an abnormality is detected in any one or more of the presence / absence judgment function, abnormality judgment function and self-diagnosis function of the controller circuit (3), a data modem (2) issues a polling signal from a center. 2. The CATV amplifier status monitor according to claim 1, wherein a signal notifying the abnormality can be sent to a center regardless of the presence or absence of a call by a polling signal or by a call by a polling signal. 3. An amplifier provided with the status monitor according to claim 1 or 2, wherein said amplifier is any one of a presence / absence determination function, an abnormality determination function, and a self-diagnosis function of a controller circuit (3). Characterized by comprising a display (5) for externally displaying results diagnosed by a plurality of CAs
TV amplifier