JPS61189740A - Supervisory equipment of communication circuit - Google Patents

Abstract

PURPOSE:To improve both the economical properties and the reliability of a communication circuit as a whole by detecting the frequency of an individual pilot signal sent from a sending end used to an analog telephone circuit for the monitor of the signal level and connecting longitudinally the monitor output. CONSTITUTION:When the alarm signal levels supplied to input terminals 80 are all equal to '0' in a circuit 20, the relay windings 40 all conduct with all relay contacts 50 turned on. While the output terminals are set at earth levels, i.e., logic level '0'. In case either one of alarm signal levels supplied to the terminals 80 is equal to '1', the windings corresponding to level '1' are nonconductive and the contacts 50 corresponding to level '1' are turned off. Then the output terminals are set at a negative potential level, i.e., logic level '1'. When the levels of the alarm signals supplied to the terminals 80 are all equal to '1', all windings 40 are nonconductive with all contact 50 turned off respectively. Then the output terminals are equal to a negative potential levels, i.e., logic level '1'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to line monitoring of an analog broadband transmission communication network, and particularly to line monitoring using pilot signals.

[Conventional technology]

Existing analog lines are being expanded as the amount of information transmitted increases. Line monitoring using pilot signals is very commonly used in analog lines.

In line monitoring using pilot signals, a monitoring method is widely used in which a separate pilot frequency is determined for each hierarchy, and the receiving end individually detects the level reached by this frequency and issues an alarm.

FIG. 3 shows a conventional communication line monitoring device. In FIG. 3, AO is a monitoring circuit that detects the frequency of the pilot signal po for the upper line bundle and monitors the level;
1 to An are monitoring circuits TO which detect the frequencies of the individual pilot signals P1 to Pn and monitor their levels.
-Tn is an output terminal for outputting an alarm signal (mainly a signal at ground potential) as a monitoring output output from the monitoring circuits AO to An, and the monitoring circuit AO is an ordinary line bandpass filter 1. Amplifier 2. Detector 3゜Relay circuit 4
The monitoring circuit AI includes a bandpass filter 11, an amplifier 12 .
Detector 13. It is composed of a relay circuit 14. - In such a device, the monitoring circuit AO and the monitoring circuits Al to An constantly monitor the level information at the pilot frequency of the upper line east pilot signal PO and the individual pilot signals PL-Pn, respectively, and output in the event of a failure such as a level abnormality. Outputs an alarm signal to terminals TO to Tn.

[Problem that the invention seeks to solve]

However, as the bandwidth becomes wider due to an increase in the amount of transmission, the filter for extracting the pilot signal is required to have suppression characteristics over a wide band and narrow band pass characteristics, which has the drawback of increasing the price. Additionally, the level of these pilot signals is generally set low to prevent line overload, and after selection, a high-gain amplifier is required to amplify it to the required level, which is another factor contributing to the high price. . Furthermore, even if the line itself is normal, if there is an abnormality in the pilot signal supply circuit or monitoring circuit for the upper line bundle, the entire line may be determined to be defective due to the abnormality.

Means for Solving Problem C] In order to solve such problems, the present invention provides a monitoring means for detecting the frequency and monitoring the level of the individual pilot signal used in the analog telephone line and sent out from the sending end. and cascade connection means for cascadingly connecting the monitoring outputs outputted from the monitoring means.

[Effect]

In the present invention, the upper line bundle is monitored by the logical sum of the monitoring outputs.

〔Example〕

An embodiment of a communication line monitoring device according to the present invention is shown in FIG. In FIG. 1, AA is the monitoring circuit A shown in FIG.
A line circuit excluding the bandpass filter l, amplifier 2, detector 3 and relay circuit 4 from O, 20 is a line monitoring circuit that enables monitoring of the upper line bundle, and 30 is an output that outputs an alarm signal for the upper line bundle. The line monitoring circuit 20 is composed of a relay circuit 21 and an OR circuit 22.

FIG. 2 shows a detailed circuit of the line monitoring circuit 20.

In FIG. 2, 40 is a relay winding, 50 is a relay contact that constitutes an OR circuit and belongs to Relay@Cotton 40, and 70 is a relay circuit that constitutes a relay circuit together with relay winding 40, and
, 60 is a strap wire, 80 is an input terminal into which the output of the monitoring circuits A1 to An is inputted, that is, an alarm signal, 90 is an output terminal for outputting an alarm signal for monitoring the individual pilot signal, 91 is a negative potential, -V is a connection terminal, 92.93 is a ground terminal for connection to ground, and relay winding 40.93 is a ground terminal for connection to ground. Relay contacts 50 constitute cascade connection means.

Next, the operation of the line monitoring circuit 20 configured as described above will be explained. The logic levels used in this circuit are as follows: earth level is r OJ, negative level is ``1'', and -V is ``1''.
”. When the alarm signal levels input to the input terminals 80 are all "0", all the relay windings 40 are energized, all the relay contacts 50 are turned on, and the output terminal is at the ground level, that is, the logic level "0". Next, when any of the alarm signal levels input to the input terminal 80 is "1", the relay winding 40 corresponding to the level "1"
is in a non-energized state, the relay contact 50 corresponding to level rlJ is turned off, and the output terminal becomes a negative potential level, that is, logic level "1". Finally, when all the alarm signal levels input to the input terminals 80 are "1", all the relay windings 40 are de-energized, all the relay contacts 50 are turned off, and the output terminals are at the negative potential level, that is, the logic level "1". ”. The relay contact 70 outputs a signal similar to the alarm signal input to the input terminal 80 to the output terminal 90.

In this way, the signal appearing at the output terminal 30 is transmitted to the monitoring circuit A1.
This is a logical sum output signal of the alarm signals output from ~An. Note that depending on the communication line, the lower line bundle may not be prepared to the maximum capacity of the upper line bundle in order to reduce the initial investment. Strap 60 shorts relay contacts 50 in the absence of these lower line bundles.

[Effects of the Invention] As explained above, the present invention provides a monitoring means for detecting the frequency and monitoring the level of an individual pilot signal used in an analog telephone line and sent out from a sending end, and a monitoring means output from this monitoring means. By providing a cascade connection means for connecting the outputs in cascade, the upper line bundle can be monitored by this m-connection means, so the required functions can be achieved with only a simple relay circuit without using expensive circuits. Satisfied and also
This has the effect of reducing the circuit scale, making the entire line more economical and highly reliable.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of a communication line monitoring device according to the present invention, FIG. 2 is a circuit diagram showing a line monitoring circuit that constitutes this device, and FIG. 3 is a conventional communication line monitoring device. It is a system diagram. A1~An...Monitoring circuit, AA...Line circuit,
T1~Tn, 30.90...output terminal, 11...
・Band filter, 12...Amplifier, 13...Detector, 14.21...Relay circuit, 20...Line monitoring circuit, 22...OR circuit, 40... ...Relay winding, 50.70...Relay contact, 60...
Strap wire, 80... Input terminal, 91.92...
··Connecting terminal. Figure 1

Claims (1)

[Claims] A communication line monitoring device for monitoring an analog telephone line using a pilot signal, comprising a monitoring means for detecting the frequency and monitoring the level of an individual pilot signal used for the analog telephone line and sent out from a sending end, and a monitoring means for detecting the frequency and monitoring the level of an individual pilot signal used for the analog telephone line and sent out from a sending end; cascade connection means for connecting monitor outputs in cascade, and monitors an upper line bundle by a logical sum of the monitor outputs.