JP2550666B2 - Monitor device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a monitor device for monitoring a single-current loop subscriber line accommodated in an exchange.

(Prior Art) FIG. 3 is a connection diagram of a conventional monitor device for a single-current loop subscriber line. As shown in the figure, the level converter 1 of the exchange and the telex device 2 on the subscriber side in the exchange are a single-current loop subscriber line (hereinafter simply referred to as a line).
Connected at 3. The level converter 1 interfaces the line 3 of ± 50 V and ± 20 mA with the exchange, and includes a reverse circuit (REV) 11 and a transmission / reception circuit (SD, RD) 12. The telex device 2 includes a receiver 21, a transmission contact 22 and the like. The test ammunition device 4 is inserted into the line 3, and the plug 51 of the monitor device 5 is inserted (fitted) into either of the plugs 41 and 42 of the test ammunition device 4. The monitor device 5 includes a receiving circuit 52 that detects a current. Such a monitor device 5 connects the transmission line 22 by disconnecting the transmission contact 22 of the telex device 2 and the transmission data by disconnection of the transmission / reception circuit 12 of the level converter 1 of the exchange to detect the current through the reception circuit 52, and thereby the line 3 is connected. I'm monitoring.

(Problems to be Solved by the Invention) However, the monitor device having the above-described configuration cannot distinguish between the transmission data from the subscriber side and the transmission data from the exchange side, and if garbled characters occur, it may be due to a collision or on the line. There was a problem that it could not be determined whether it was due to the obstacles of.

The present invention eliminates the above-mentioned problems, and provides a monitor device capable of individually saving data of transmissions from a subscriber side and transmissions from an exchange side and detecting a collision. To aim.

(Means for Solving the Problem) In order to solve the above problems, the present invention provides a monitor device for monitoring a single-current loop subscriber line accommodated in an exchange, in which a current of the single-current loop subscriber line is changed. Current detecting means based on an output signal of the voltage detecting means, and receiving means including current detecting means for detecting and outputting the detection result, voltage detecting means for detecting the voltage of the line and outputting the detection result, Collision detection for detecting a collision of transmission data depending on whether or not the output timings of the output signals of the current detection means and the voltage detection means coincide with the separation means for separating the output signal of the means into subscriber side data and exchange side data. And means.

(Operation) The technical means of the present invention operates as follows. The separating means (for example, a separating circuit described later) does not change the voltage of the line when, for example, the transmission data from the subscriber side is received intermittently, and the output signal of the voltage detecting means (for example, a voltage detecting circuit described later). Is constant, it works so as to output the output signal of the current detecting means (for example, a current detecting circuit described later) as output data on the subscriber side. In addition, when receiving transmission data from the exchange side due to interruption, the voltage of the line changes and the output signal of the voltage detecting means changes correspondingly, so the separating means changes the output signal of the current detecting means. It works to output as transmission data from the exchange. The collision detection means (for example, a collision detection circuit to be described later) determines that the output timings of the output signals of the current detection means and the voltage detection means are normal, and if they do not match, determines a collision and indicates a collision detection. Works to output a signal. Thus, as the receiving means, the voltage detecting means is provided in addition to the current detecting means, and the separating means for separating the transmission data based on these output signals and the collision detecting means for detecting the collision are provided. The problem of can be solved.

(Embodiment) FIG. 1 is an equivalent circuit diagram showing an embodiment of the present invention, showing a monitor state in which a connection between a subscriber side and an exchange side is completed and communication is not performed (idle state). It is shown. In the figure, the same reference numerals as those in FIG. 3 indicate the same components. Also in this embodiment, the test ammunition device 4 is used to connect the monitor device 5a to the line 3 by fitting the plug 51 of the monitor device 5a into the connectors 41 and 42 thereof as in FIG. In the figure, they are omitted for simplicity of explanation. In the monitor device 5a of the present embodiment, in addition to the plug 51 as in the conventional case, the receiving circuit 52a, the separation circuit 5
3 and a collision detection circuit 54. The receiving circuit 52a is connected to the line 3
In addition to the current detection circuit 521 that detects the current and outputs the detection result (TTL level), a voltage detection circuit 522 that detects the voltage of the line 3 and outputs the detection result (TTL level) is provided.
The separation circuit 53 is composed of AND gates 531 and 532 and a mono-multivibrator (M / M) 533. Separated into data (EX). The collision detection circuit 54 includes an exclusive OR gate (EXOR) 54.
1, an AND gate 542, and a timer 543, and detects a collision of transmission data by the match / mismatch of the output signals of the current detection circuit 521 and the voltage detection circuit 522. Figure 2 (a),
(B) and (c) are signal diagrams of current, voltage, and TTL level of each part in the circuit of FIG. 1 at the time of transmission on the subscriber side, transmission on the exchange side, and collision.

 Next, the operation of this embodiment will be described.

First, the case of receiving (monitoring) the transmission data from the subscriber side will be described.

When the telex device 1 on the subscriber side starts transmission, transmission data due to the intermittent connection of the transmission contact 22 is sent to the line 3. Current detection circuit 52 when the loop current of line 3 is off
1 detects 0 amperes, and the voltage detection circuit 522 receives + 50V constantly from the level converter 1. As a result,
Since the output signal of the voltage detection circuit 522 does not change at “H”, M
The output signal (VL) of / M533 is always "L" (see FIG. 2 (a)). Therefore, when the output signal of M / M533 is "L",
Since the AND gate 531 opens (valid) and the AND gate 532 closes, the data transmitted by the transmission contact 22 is the current detection circuit.
After being detected by 521 and converted to the TTL level, the data is output from the AND gate 531 as subscriber side data (SUB).

Next, the case of receiving the transmission data from the exchange side will be described.

When the exchange side starts transmission, the transmission / reception circuit 12 of the level converter 1 sends out the transmission data due to the interruption to the line 3. When the transmitter / receiver circuit 12 changes from + 50V to -50V,
This is detected by the voltage detection circuit 522, converted to the TTL level, and sent to the M / M 533 of the separation circuit 53. As a result, the M / M533 sets its output signal to "H" for 150 ms (however, 50 baud) for one character (see FIG. 2 (b)). Therefore, the AND gate 531 is closed and the AND gate 532 is opened.
Therefore, when the current detection circuit 521 detects the transmission data due to the on / off of the transmission / reception circuit 12 as the +/- 20 mA, 0 A on / off data, it converts this to the TTL level and outputs it as the exchange side data (EX) via the AND gate 532. .

Next, the operation at the time of collision of transmission data will be described. The collision detection circuit 54 detects a collision when the waveforms of the output signals of the current detection circuit 521 and the voltage detection circuit 522 are different. That is, the output of the current detection circuit 521 and the output of the voltage detection circuit 522 are output to the EXOR 541. Also, by using the output of EXOR541 as one input of AND gate 542 and the output of M / M533 as the other input of AND gate 542, the case of transmission on the subscriber side (Fig. 2 (a)) Do not detect as a collision. Furthermore, since the time required for detection differs between current detection and voltage detection, the output of the AND gate 542 is input to the timer 543, and only when the output of the AND gate 542 is “H” for a certain period of time, it is determined that a collision has occurred. , The detection flag (CO) is raised.

In FIG. 2 (c), the subscriber side first starts transmission, and then the exchange side starts transmission. Therefore, first, the output of the current detection circuit 521 becomes "H", whereby the subscriber side data (SUB) becomes "H". Next, the voltage detection circuit 522
When the voltage is detected, a collision occurs, the exchange side data (EX) becomes “H”, and the timer 543 starts.
Then, after the elapse of the predetermined time, the collision detection flag (CO) becomes “H”.

As described above, according to this embodiment, the current detection circuit 521,
Since the voltage detection circuit 522, the separation circuit 53 and the collision detection circuit 54 are provided, the transmission data on the subscriber side or the exchange side can be separated and monitored. Therefore, when the characters are garbled,
A collision can be immediately determined on the subscriber side or the exchange side, and the complaint processing for the line 3 and the like becomes easy. Further, since the separated data can be recorded, it is expected that the monitor contents are easy to read and the work efficiency is improved.

(Effects of the Invention) As described in detail above, according to the present invention, a voltage detecting means other than the current detecting means is provided as the receiving means, and the separating means and the collision means for separating the transmission data based on these output signals. Since the collision detection means for detecting the transmission data is provided, it is possible to easily determine whether the transmission data is from the subscriber side or the exchange side, and it is possible to surely detect the collision of the transmission data. Therefore, it is possible to easily and quickly detect and analyze the failure of the single-current loop subscriber line.

[Brief description of drawings]

FIG. 1 is a block diagram of a monitor device showing an embodiment of the present invention,
2 (a), (b) and (c) are signal diagrams of the embodiment of FIG. 1, and FIG. 3 is a connection diagram of a conventional monitor device. 1 ... Level converter, 2 ... Telex device, 3 ... Line, 4 ... Test ammunition device, 5a ... Monitor device, 11 ... Reverse circuit, 12 ... Transceiver circuit, 21 ... Receiver, 22 ...... Transmission contact, 41,42 …… Connector, 51 …… Plug, 52a …… Reception circuit, 53 …… Separation circuit, 54 …… Collision detection circuit, 521 …… Current detection circuit, 522 …… Voltage detection circuit, 531,532,542 …… And gate, 533 …… Mono multivibrator, 541 …… Exclusive OR gate, 543 …… Timer.

Claims (1)

(57) [Claims] 1. A monitor device for monitoring a single-current loop subscriber line accommodated in an exchange, the current detecting means for detecting a current of the single-current loop subscriber line and outputting a detection result, and a current detecting means for the line. Receiving means including voltage detecting means for detecting a voltage and outputting the detection result, and based on the output signal of the voltage detecting means, the output signal of the current detecting means is separated into subscriber side data and exchange side data. A monitor device comprising: a separation means; and a collision detection means for detecting a collision of transmission data depending on whether output timings of output signals of the current detection means and the voltage detection means match.