JPH02166931A - Alarm signal selection circuit - Google Patents

Abstract

PURPOSE:To reduce a load on the processing of communication equipment monitoring facility by providing a circuit disconnection judging circuit, and prohibiting the output of the alarm signal of line disconnection from a receiver connected to the output of a common amplifier part by a prohibition signal from the judging circuit. CONSTITUTION:Response signals 10a and 10b from a switch 2 and alarm signals 11a and 11b from reception system common amplifier parts 3A and 3B are inputted to the circuit disconnection judging circuit 9. The circuit disconnection judging circuit 9 sends the prohibition signal to prohibit the sending of the alarm signal generating in the receivers 6A-6D connected to the output of the common amplifier parts to the outside when a fault occurs in the common amplifiers 3A and 3B and the switch 2 is operated to the receivers 6A-6D. Therefore, an inhibit circuit 8 in each of the receivers 6A-6D is operated by the prohibition signal, and the sending of the alarm signal to the communication equipment monitoring facility is prohibited. In such a way, it is possible to prevent an unrequired alarm signal from being sent to the communication equipment monitoring facility by generating line disconnection signals incidentally by a large number of receivers, and to reduce the load on the processing of the communication equipment monitoring facility.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to receiving system communication equipment having a redundant configuration, and in particular to processing of monitoring equipment by preventing unnecessary alarm signals from being sent to communication equipment monitoring equipment. The present invention relates to an alarm signal selection circuit for reducing burden.

[Conventional technology]

In general, communication equipment often employs a redundant configuration for equipment in consideration of reliability and maintainability. For example, in a receiving system, a plurality of common amplification sections are provided at upstream positions close to the antenna side, and these are switched by a switch.

On the other hand, receiving communication equipment is configured to output an alarm upon detecting a failure such as a disconnection of a line, and to receive this alarm at communication equipment monitoring equipment and display an alarm or sound an alarm.

This line disconnection signal includes an out-of-band noise alarm, a pilot signal alarm, a carrier disconnection alarm, and the like.

Therefore, in such reception communication equipment, failures in the redundant configuration are dealt with by the redundant configuration itself, only failures in other parts are detected and alarm signals are output, and the communication equipment monitoring equipment executes predetermined processing. It is desired that the system be configured to do so.

[Problem to be solved by the invention]

However, in conventional receiving systems, many receivers connected to the output end of the common amplification section may receive a line disconnection signal due to a failure in the common amplification section or a line break during the operation of the redundant system switch. This may cause a large number of unnecessary alarm signals to be sent to the communication equipment monitoring equipment that are unrelated to the disconnection of the individual channels received by each receiver.

For this reason, conventionally, the communication device monitoring equipment side determines whether the alarm is caused by an upstream side, and then displays an alarm or sounds an alarm. However, with this method, when the number of receiving channels increases and the number of receivers increases, or when there are many types of signals being monitored,
Since a considerable number of alarm signals are generated at the same time, the processing load becomes large, and if the processing capacity of communication equipment monitoring equipment is small, there is a problem that overflow may occur.

One way to deal with this is to further increase the processing capacity of communication equipment monitoring equipment to prevent overflows, but this is not a good idea as the equipment would be too expensive.

The present invention provides an alarm system that prevents alarm signals from being sent to communications equipment monitoring equipment in the event of a failure in a common amplifier unit or line disconnection during operation of a redundant system switching device, thereby reducing the processing burden on communications equipment monitoring equipment. The purpose of the present invention is to provide a signal selection circuit.

[Means for Solving the Problems] The alarm signal selection circuit of the present invention inputs an alarm signal from a common amplifier section and a response signal from a redundant system switch connected to this common amplifier section, and selects a common amplifier. The system is equipped with a line disconnection determination circuit that outputs a prohibition signal by determining whether the line is disconnected when the unit fails or when the redundant system switch is operating. The configuration is such that the output of a warning signal for disconnection is prohibited.

(Operation) In the above-described configuration, the receiver is prohibited from incidentally generating a line disconnection signal when the common amplifier section fails and when the redundant system switch is in operation.

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

FIG. 1 is a block diagram of an embodiment of an alarm signal selection circuit according to the present invention. Further, FIG. 2 is a circuit diagram of the line disconnection determination circuit in FIG. 1, and FIG. 3 is a time chart for explaining the operation.

In FIG. 1, the received signal from antenna l is transferred to switch 2.
The signal is received by the two receiving system common amplifiers 3A and 3B. Further, this received signal is connected to a distributor 5 via a switch 4 that rotates in conjunction with the switch 2, and is switched to four receivers 6A, 6B, 6C, and 6C in the distributor 5, respectively. is output. In addition, switchers 2 and 4
is automatically switched to select a normal common amplification section by an alarm signal output from the receiving system common amplification sections 3A and 3B.

The receivers 6A to 6D have a built-in channel-compatible line disconnection detection circuit 7, which is connected to the inhibit circuit 8, as represented by the receiver 6A in the figure.
The configuration is such that an alarm signal is sent from each terminal 13A to 13D to communication equipment monitoring equipment.

On the other hand, the response signal 10a of the switch 2 is sent to the line disconnection determination circuit 9.
, 10b, and a receiving system common amplification section 3A.

3B alarm signals 11a and llb are input. The response signal 10a is a response signal of the switch 2 when the antenna 1 and the common amplifier section 3A are connected, and the response signal fob is a response signal when the opposite is the case.

As will be described later, this line disconnection determination circuit 9 prohibits external transmission of an alarm signal generated by a receiver connected to the output of the common amplifier when the common amplifier fails or when the line is disconnected while the switching device is operating. The receivers 6A to 6 send prohibition signals for
It is configured to send to D. For this reason, each received i6
In A to 6D, the channel-compatible line disconnection detection circuit 7
Although the alarm signal is also generated, the line disconnection judgment circuit 9
The inhibit circuit 8 is activated by the prohibition signal sent from the communication device monitoring equipment, and the sending of the alarm signal to the communication equipment monitoring equipment is prohibited.

Next, the line disconnection determination circuit 9 will be explained in detail using FIG.

The first line disconnection determination circuit, which sends out a prohibition signal when all of the common amplifiers 3A and 3B are in failure, is constructed by calculating the AND of the alarm signals of the common amplifiers in the AND circuit 14.

Next, only when one common amplifying section that amplifies the received signal generates an alarm, switching to the common amplifying section on the standby side is performed and the switch 2 starts operating, but until then, the prohibition signal is The second line disconnection determination circuit for sending out the signal includes an AND circuit 15A that inputs the alarm signal 11a of the common amplifier 3A and the response signal 10a of the switch 2, and a logic product circuit 15A that inputs the alarm signal 11a of the common amplifier 3A and the response signal 10a of the switch 2; 2, an exclusive OR circuit 16 that receives the output signals of the AND circuits 15A and 15B, and a one-shot multi-bye break circuit 17 and a retrigger multi-byte circuit connected to the outputs thereof. It is composed of a break circuit 18.

Furthermore, a third line disconnection determination circuit that sends out a prohibition signal while the switch 2 is in operation is constituted by an exclusive OR circuit 19 that inputs the response signals 10a and 10b of the switch 2, and an inverter circuit 20.

Said 1st. Second. The output of the third line disconnection determination circuit is input to the OR circuit 21 and then connected to the output signal extension circuit 27.

The output signal extension circuit 27 includes a photocoupler 22.degree. resistor 23. Capacitor 24. It is composed of a variable resistor 26 and a comparator 25, and continues to send the prohibition signal during the period required for the unnecessary line disconnection alarm generated in the receiver to be canceled.

The operation of the line disconnection determination circuit 9 will be explained below with reference to FIG. Here, as an example, the operation of each part is shown when the common amplifier section 3A in operation becomes a failure, the switch 2 operates, and backup is performed by the common amplifier section 3B.

The response signal 10a input to point B1 ceases to respond when the switch 2 starts operating, and the response signal 10b input to point 82 responds when the switch 2 ends its operation. In this case, when the switch 2 finishes its operation, the response signal 10a input manually to point B1 ceases to respond, and when the switch 2 starts operating, the response signal 10b input to point 82 responds even in the case of a switch. , the output signals at point D are the same.

The pulse width of the retrigger multi-by-break circuit 18 is set in advance so that the output signal at point F continues to be generated for a period from when the switch 2 starts operating until the response signal 10a or 10b changes. Further, the output signal at the 0 point is generated only when the response signals 10a and 10b are the same, that is, when the switch 2 is in operation.

Therefore, the signal at the output point H of the OR circuit 21 sends out a prohibition signal during the failure of the common amplifier section and the accompanying disconnection period during the operation of the switch 2, and the common amplifier 3B on the standby side outputs a prohibition signal. When the backup is completed, the transmission of the prohibition signal will be stopped.

By the way, after the line disconnection detection circuit 7 corresponding to the channels in the receivers 6A to 6D is activated due to line disconnection, even if the line is restored to normal by the operation of the redundant system switch, the signal of the line disconnection detection circuit 7 stops. It may take some time depending on the type of signal being detected and the detection circuit. Therefore, it is necessary to also prohibit alarm signals during that time.

Therefore, by adjusting the discharge waveform at one point of the output signal extension circuit 27 and the comparison voltage using the variable resistor 26, the extension period of the prohibition signal at point H can be adjusted for the period necessary for the signal of the line disconnection detection circuit 7 to stop. After adjustment, prohibition signals are sent to the inverter circuits 8 of the receivers 6A to 6D as output signals at five points, thereby preventing unnecessary alarm signals from being sent.

In the above embodiment, there are two common amplifier units and four receivers.
Although the case in which the number of units is used is shown, the present invention is not limited to this number of units.

〔Effect of the invention〕

As explained in detail above, according to the present invention, when there is a failure in the reception system common amplifier section near the antenna side or due to a line disconnection that occurs during the operation of the redundant system switch, the connection to the output end of the common amplifier section The effect of preventing the large number of receivers in the network from incidentally generating line disconnection signals and sending out unnecessary alarm signals to the communication equipment monitoring equipment, and reducing the processing burden on the communication equipment monitoring equipment. There is.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the alarm signal selection circuit according to the present invention, FIG. 2 is a detailed circuit diagram of the line disconnection determination circuit in FIG. 1, and FIG. 3 is an operation of the line disconnection determination circuit according to the present invention. In order to explain this, signal waveforms at each point in FIG. 2 are shown. ! ...Antenna, 2,4...Switcher, 3A, 3B.
...Common amplifier section, 5...Distributor, 6A to 6D...Receiver, 7...Line disconnection detection circuit, 8...Inverter circuit, 9...Line disconnection determination circuit, 10a, 10b ...Switcher response signal, lla, llb...Common amplifier alarm signal, 12...Alarm prohibition signal, 13A to 13D...Line disconnection alarm signal sending terminal, 14.15A, 15B...Logic Product circuit, 16.19... Exclusive OR circuit, 17.
...One-shot multivibrator circuit, 18...
Retriggerable multi-vibration circuit, 20... Inverter circuit, 21... OR circuit, 22... Photo coupler, 23... Resistor, 24... Capacitor,
25... Comparison calculator, 26... Variable resistor, 27...
・Output signal slow C2! Third

Claims (1)

[Claims] 1. In a receiving system comprising a redundant common amplifying section and a receiver connected to the output of the common amplifying section, the receiver is configured to generate an alarm signal due to line disconnection. Input the alarm signal from the section and the response signal from the redundant system switch connected to this common amplifier section, respectively.
A line disconnection determination circuit is provided that determines line disconnection during a failure of the common amplifier section and during operation of the redundant system switch and outputs a prohibition signal, and the prohibition signal prohibits the output of the alarm signal from the receiver. An alarm signal selection circuit comprising: