JPS63196145A - Signal detector - Google Patents

Signal detector

Info

Publication number
JPS63196145A
JPS63196145A JP2724287A JP2724287A JPS63196145A JP S63196145 A JPS63196145 A JP S63196145A JP 2724287 A JP2724287 A JP 2724287A JP 2724287 A JP2724287 A JP 2724287A JP S63196145 A JPS63196145 A JP S63196145A
Authority
JP
Japan
Prior art keywords
signal
time
detection circuit
circuit
level
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2724287A
Other languages
Japanese (ja)
Inventor
Sunao Ronte
素直 論手
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Anritsu Corp
Original Assignee
Anritsu Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Anritsu Corp filed Critical Anritsu Corp
Priority to JP2724287A priority Critical patent/JPS63196145A/en
Publication of JPS63196145A publication Critical patent/JPS63196145A/en
Pending legal-status Critical Current

Links

Landscapes

  • Monitoring And Testing Of Exchanges (AREA)

Abstract

PURPOSE:To detect an on/off-signal pattern accurately by supervising the level state of both outputs of a delay detection circuit not following up impulsive noise and of a fast speed detecting circuit and outputting the result as an on- signal when both the outputs are at high levels. CONSTITUTION:When an input signal including impulsive noise is inputted to a terminal 21, the delay detection circuit 22 does not respond to the impulsive noise. On the other hand, the fast speed detection circuit 23 responds to the impulsive noise. Thus, the circuits 22, 23 are provided and a signal propriety supervisory means 24 regards it as a substantial signal at a prescribed level based on both the output states, the output of a time count circuit 27 is outputted as an on-time signal, then the start time of an original signal is found out accurately, while the other noise signal as impulsive noise is eliminated surely.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、例えば電話回線網の回線品質の一試験項目で
ある各種トーン信号等の遅延時間を測定する回線品質測
定装置等に利用される信号検出装置に係わり、特にイン
パルス性ノイズによる影響を防止する手段を設けた信号
検出装置に関する。
Detailed Description of the Invention (Field of Industrial Application) The present invention is used, for example, in a line quality measurement device that measures the delay time of various tone signals, etc., which is a test item for the line quality of a telephone line network. The present invention relates to a signal detection device, and particularly to a signal detection device provided with means for preventing the influence of impulsive noise.

(従来の技術〉 一般に、電話回線網の加入者端に接続される各種用途の
端末機器は、ダイヤルトーン、リングバックトーン、ビ
ジートーン等の各種トーン信号を検出しながら交換機と
のインターフェースを確立し通話を行っている。これら
のトーン信号は単一正弦波信号をある時間ごとにオン・
オフ制御して送出するもので、例えばダイヤルトーンは
400−の連続波信号を送出しく第4ti!!la)、
リングバックトーンはオン時間1SeC,オフ時fi1
2 secでオン・オフさせて送出しく第4図b)、ビ
ジートーンはオン時B 5001sec、オフ時間50
0 wsecでオン・オフさせて送出する(第4図C)
。従って、このような信号の性質を識別して交換機との
インターフェースを確立する必要がある。
(Prior art) In general, terminal equipment for various purposes connected to the subscriber end of a telephone line network establishes an interface with a switchboard while detecting various tone signals such as dial tone, ringback tone, and busy tone. These tone signals turn on and off a single sine wave signal at certain times.
For example, the dial tone is a 400-continuous wave signal that is transmitted with off control. ! la),
Ringback tone is on time 1SeC, off time fi1
It is turned on and off in 2 seconds and sent out (Fig. 4 b), the busy tone is on when B is 5001 seconds, and the off time is 50
Turn on/off and send at 0 wsec (Figure 4C)
. Therefore, it is necessary to identify the nature of such signals to establish an interface with the switch.

一方、交換機とのインターフェースの端末装置。On the other hand, the terminal device interfaces with the exchange.

特に回線品質測定装置としては、オン・フック後のダイ
ヤルトーン到来時間(M延時間)およびダイヤリング後
のリングバックトーン到来時間(遅延時m)を正確に測
定することが交換機の能力。
In particular, as a line quality measuring device, the ability of a switch to accurately measure the dial tone arrival time after on-hook (M delay time) and the ringback tone arrival time after dialing (delay time m) is important.

動作状態を把握する上の1つの試験項目として非常に重
頁視されている。
It is considered very important as a test item to understand the operating state.

ところで、以上のような各種のトーン信号を正確に識別
し、かつ、それらの信号の遅延時間を測定するに際し交
換機と端末機器間で生じるノイズが問題となってくる。
However, when accurately identifying the various tone signals as described above and measuring the delay times of these signals, noise generated between the switching equipment and the terminal equipment becomes a problem.

そこで、従来、かかるノイズ除去手段として、第5図に
示すようにトーン信号等の周波数成分を取り出する波H
1と、このろ波!11の出力を予め定めた基準レベルと
を比較し、ろ波器1の出力レベルが基準レベルを越えた
ときにオン時間を意味する“1″レベル信を出力し、基
準レベル以下のときにオフ時間を意味する“0”レベル
信号を出力するしきい値検出回路2とを備え、このしき
い値検出回路2の出力からトーン信号を識別している。
Therefore, as shown in FIG. 5, as a noise removing means, conventionally, a wave H is used to extract frequency components such as a tone signal.
1 and this filter! The output of filter 11 is compared with a predetermined reference level, and when the output level of filter 1 exceeds the reference level, it outputs a "1" level signal indicating the on time, and when it is below the reference level, it is turned off. A threshold detection circuit 2 outputs a "0" level signal indicating time, and a tone signal is identified from the output of the threshold detection circuit 2.

第6図(a)はる波!11の入力信号で、(イ)は本来
の入力信号、(ロ)はインパルス性ノイズを示す。同図
(b)はしきい値検出回路2の出力信号を示す。
Figure 6 (a) Harunami! 11 input signals, (a) shows the original input signal, and (b) shows impulsive noise. FIG. 2B shows the output signal of the threshold value detection circuit 2. FIG.

(発明が解決しようとする問題点) しかし、以上のような信号検出装置は、第6図に示すよ
うに本来の信号(イ)にインパルス性ノイズ(0)が重
畳されていると、しきい値検出回路2から本来の信号の
みならず、ノイズ(ロ)からもオン時間を意味する1”
レベル信号が出力され、その結果、オン・オフ時間に誤
動作が生じ、信号の性質を正確に識別できない問題があ
る。
(Problem to be Solved by the Invention) However, as shown in FIG. 1”, which means the on-time, from the value detection circuit 2 not only from the original signal but also from the noise (b)
A level signal is output, resulting in malfunctions during on/off time, and there is a problem in that the nature of the signal cannot be accurately identified.

このため、かかる不具合を解決する手段として、ろ波器
1とし、きい値検出回路2との間にエネルギー感知手段
を設け、信号のエネルギーに応じて充・放電動作を行わ
せることが考えられる。しかし、このような考えの前提
には、ある信号エネルギーに達したときにしきい値検出
回路2から1”レベル信号を出力するエネルギー積分型
の機能を持つために、例えば第7図(a)に示すような
入力信号に対し、しきい値検出回路2からは時間Tdの
遅れを持つ出力信@(第7図b)が出力されるので、信
号の時間を正確に検出できない問題がある。しかも、こ
の遅れ時間Tdは信号の種類によって異なるオン・オフ
パターンに応じて変化するので、測定の際にその遅れ時
間を計算することができない。
Therefore, as a means to solve this problem, it is conceivable to provide the filter 1 with energy sensing means between it and the threshold detection circuit 2, and to perform charging/discharging operations according to the energy of the signal. However, this idea is based on the premise of having an energy integration type function that outputs a 1" level signal from the threshold detection circuit 2 when a certain signal energy is reached, for example as shown in FIG. 7(a). In response to an input signal as shown, the threshold detection circuit 2 outputs an output signal @ (FIG. 7b) with a delay of time Td, so there is a problem that the time of the signal cannot be detected accurately. Since this delay time Td changes according to on/off patterns that differ depending on the type of signal, it is impossible to calculate the delay time during measurement.

本発明は上記実情に議みてなされたもので、インパルス
性ノイズの影響を受けることなく正確にオン・オフの信
号パターンを検出し得る信号検出装置を提供することを
目的とする。
The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a signal detection device that can accurately detect on/off signal patterns without being affected by impulsive noise.

(問題点を解決するための手段) 本発明による信号検出装置は、入力信号に重畳されるイ
ンパルス性ノイズに追従しない応答の遅い遅動検出回路
と、応答の迷い速動検出回路と、前記両検出回路の出力
レベルが所定のレベル条件のときにノイズでない本来の
入力信号が入力されたと判断する信号良否監視手段と、
前記速動検出回路の出力レベルが所定レベルとなったと
きそのレベル状態の時間を計数し、前記信号良否監視手
段から本来の信号有りの信号を受番すると前記計数時間
信号を出力する時間計数手段とを備え、たちのである。
(Means for Solving the Problems) A signal detection device according to the present invention comprises: a slow motion detection circuit with a slow response that does not follow impulsive noise superimposed on an input signal; a fast motion detection circuit with a erratic response; signal quality monitoring means for determining that an original input signal that is not noise is input when the output level of the detection circuit is at a predetermined level condition;
Time counting means for counting the time of the level state when the output level of the rapid motion detection circuit reaches a predetermined level, and outputting the counted time signal when receiving a signal indicating that the original signal is present from the signal quality monitoring means. We are prepared for this.

(作用) 従って、以上のような手段とすることにより、インパル
ス性ノイズに追従しない遅動検出回路と応答の速い速動
検出回路の両出力のレベル状態を信号良否監視手段で監
視し、両出力ともハイレベルであればインパルス性ノイ
ズの含まない本来の信号が入力されたと判断する。一方
、速動検出回路の出力レベルがハイレベルとなったとき
そのレベル状態の時間を時間計数手段で計数し、前記信
号良否監視手段から良と判断されたときに前記計数時間
信号をオン時間信号として出力するものである。
(Function) Therefore, by using the above means, the level state of both the outputs of the slow motion detection circuit that does not follow impulsive noise and the fast motion detection circuit that responds quickly is monitored by the signal quality monitoring means, and both outputs are monitored. If both are at high level, it is determined that the original signal containing no impulsive noise has been input. On the other hand, when the output level of the fast motion detection circuit becomes a high level, the time of the level state is counted by a time counting means, and when the signal quality monitoring means determines that the output level is good, the counted time signal is converted into an on-time signal. This is what is output as.

(実施例) 以下、本発明の一実施例について図面を参照して説明す
る。第1図は本願に係わる信号検出装置の適用箇所を示
す因である。一般に、この種の電話回線網システムは、
第1図に示すように交換機加入者1路11とハイブリッ
ドコイル12との間にダイヤルパルス送出用接点13お
よび直流阻止用コンデンサ14が介在され、かつ、ハイ
ブリッドコイル12の他方の巻線の中間端子にダイヤル
トーンその他の必要な信号例えば回線品質を測定するた
めの信号を送出する信号送出装置15が接続され、更に
前記他方の巻線の外側端子に本願に係わる信号検出装置
116が接続されている。17は発信指令または着信状
態を検出して所要とする制御信号を適宜な構成要素に与
える制御部、18は発信時にtsm部17からの制御信
号を受けてダイヤルパルスを送出するための信号をダイ
ヤルパルス送出用接点13に与えてダイヤルパルスを送
出させ、着信時には着信検出信号に基づいてダイヤルパ
ルス送出用接点13を閉結するダイヤルパルス送出回路
である。
(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows the locations where the signal detection device according to the present application is applied. Generally, this type of telephone network system is
As shown in FIG. 1, a dial pulse sending contact 13 and a DC blocking capacitor 14 are interposed between the exchange subscriber line 11 and the hybrid coil 12, and the intermediate terminal of the other winding of the hybrid coil 12 A signal transmitting device 15 for transmitting a dial tone and other necessary signals, such as a signal for measuring line quality, is connected to the terminal, and a signal detecting device 116 according to the present application is further connected to the outer terminal of the other winding. . Reference numeral 17 indicates a control unit that detects an outgoing command or an incoming call state and provides necessary control signals to appropriate components; 18 indicates a dial signal that receives a control signal from the TSM unit 17 at the time of an outgoing call and sends out a dial pulse; This is a dial pulse sending circuit that supplies a dial pulse to the pulse sending contact 13 to send out a dial pulse, and closes the dial pulse sending contact 13 based on an incoming call detection signal when an incoming call is received.

しかして、以上のようなシステムにおいては、例えば発
信時、オフ・フック後交換機(図示せず)からのダイヤ
ルトーンを信号検出装置16を介して確認した後、制御
部17から制御信号を出力しダイヤ、ルパルス送出用接
点13をオン・オフtUaしてダイヤル信号を送出する
。しかる後、信号検出装置16を用いてリングバックト
ーンを検出し相手側の接続応答を確認する。電話回線網
の回線品質の測定でも同様な要領で回線接続を行った後
、回線測定用信号を送出して前記信号検出装置16で回
線品質を測定する。
In the above system, for example, when making a call, after confirming the dial tone from the off-hook exchange (not shown) via the signal detection device 16, the control section 17 outputs a control signal. The dial signal is sent by turning the dial/pulse sending contact 13 on/off tUa. Thereafter, the signal detection device 16 is used to detect a ringback tone and confirm the connection response of the other party. In measuring the line quality of a telephone line network, after the line is connected in the same manner, a line measurement signal is sent out and the signal detection device 16 measures the line quality.

次に、第2図は本発明に係わる信号検出装置の一具体例
を示す構成図である。同図において21はハイブリッド
コイル12側から入力される入力信号を受ける入力端子
であって、この端子21には相反する機能を持った遅動
検出回路22および遅動検出回路23が接続されている
。この遅動検出回路22は応答性が遅くインパルス性ノ
イズに追従できない信号検出機能を有し、一方、速動検
出回路23は応答性が速い信号検出機能を持っている。
Next, FIG. 2 is a block diagram showing a specific example of a signal detection device according to the present invention. In the figure, 21 is an input terminal that receives an input signal input from the hybrid coil 12 side, and a slow detection circuit 22 and a slow detection circuit 23, which have contradictory functions, are connected to this terminal 21. . The slow motion detection circuit 22 has a signal detection function that has a slow response and cannot follow impulsive noise, while the fast motion detection circuit 23 has a signal detection function that has a quick response.

そして、これら両検出回路22.23の出力側には信号
良否監視手段24が設けられている。
A signal quality monitoring means 24 is provided on the output side of both of these detection circuits 22 and 23.

この信号良否監視手段24は、両検出回路22゜23の
出力が1”の時に1”レベル信号を出力する例えばアン
ド回路等で構成された論理ゲート回路25と、この論理
ゲート回路25の出力から“1”レベル信号の有無を監
視し“1”レベル信号有りの場合には本来の信号が入力
されたと判断し、その“1”レベル信号を計数する状態
監視用計数回路26により構成されている。27は速動
検出回路23の出力が“O”→″1”に変化したときそ
の“1″レベル状態の時間を計数する時間計数回路であ
る。28は各計数回路26.27をリセットするリセッ
ト回路である。各計数回路26.27はリセット回路2
8の出力が“0”→“1”のレベル変化のとき計数を開
始し、′1”→“ONのレベル変化のとき計数動作をリ
セットする。29は状態監視用計数回路26から″1″
レベル信号が入力されたとき前記時間計数回路27で計
数された時間信号をオン時間信号として出力するバッフ
ァ回路である。
This signal quality monitoring means 24 includes a logic gate circuit 25, which is configured with an AND circuit, for example, which outputs a 1" level signal when the outputs of both detection circuits 22 and 23 are 1", and an output from this logic gate circuit 25. It is composed of a status monitoring counting circuit 26 that monitors the presence or absence of a "1" level signal, determines that the original signal has been input when a "1" level signal is present, and counts the "1" level signal. . 27 is a time counting circuit that counts the time that the output of the fast motion detection circuit 23 is in the "1" level state when it changes from "O" to "1". 28 is a reset circuit that resets each counting circuit 26, 27. Each counting circuit 26.27 is a reset circuit 2
Counting is started when the level of the output of 8 changes from "0" to "1", and the counting operation is reset when the level changes from '1' to "ON". 29 is "1" from the status monitoring counting circuit 26
This buffer circuit outputs the time signal counted by the time counting circuit 27 as an on-time signal when a level signal is input.

次に、以上のように構成された装置の動作を説明する。Next, the operation of the apparatus configured as above will be explained.

先ず、前記ダイヤルパルス送出用接点13のオフ・フッ
ク時点に発せられるリセット回路28の“0”→″1”
のレベル変化で各計数回路26.27が計数動作可能状
態に設定される。
First, when the dial pulse sending contact 13 goes off-hook, the reset circuit 28 changes from "0" to "1".
When the level changes, each of the counting circuits 26 and 27 is set to a counting operation enabled state.

この状態において端子21に第3図(a)に示す例えば
インパルス性ノイズ(ハ)を含んだ入力信号が入力され
ると、遅動検出回路22ではインパルス性ノイズ(ハ)
に対して応答しないので同図(b)に示すような信号を
出力し、一方、速動検出回路23ではインパルス性ノイ
ズ(ハ)に応答して同図(C)の様な信号を出力する。
In this state, if an input signal containing, for example, impulsive noise (c) shown in FIG. 3(a) is input to the terminal 21, the slow motion detection circuit 22
Since there is no response to the noise, it outputs a signal as shown in (b) of the same figure. On the other hand, the fast motion detection circuit 23 outputs a signal as shown in (C) of the same figure in response to the impulsive noise (c). .

これら両検出回路22.23の出力は論理ゲート回路2
5に送られ、ここで″1″レベルの時に1”レベル信号
を出力し、状態監視用計数回路26へ送出する。この状
態監視用計数回路26は論理ゲート回路25から“1”
レベル信号が入力されると本来の信号が入力されたと見
なし、そのレベル信号を計数(第3図d)するとともに
バッファ29を動作状態に設定する。
The outputs of these two detection circuits 22 and 23 are the logic gate circuit 2.
When the signal is at the "1" level, it outputs a "1" level signal and sends it to the status monitoring counting circuit 26. This status monitoring counting circuit 26 receives the "1" signal from the logic gate circuit 25
When a level signal is input, it is assumed that the original signal has been input, and the level signal is counted (FIG. 3d) and the buffer 29 is set to an operating state.

一方、遅動検出回路23の出力は論理ゲート回路25と
ともに、時間計数回路27にも送出される。ここで、時
間計数回路27は遅動検出回路23の出力が“0″から
1”にレベル変化したときその“1”レベルの状態を時
圓計数し、その計数時間を同図(e)に示すようにオン
時間信号として前記バッファを通して出力する(第3図
f) 。
On the other hand, the output of the delay detection circuit 23 is sent to the time counting circuit 27 as well as the logic gate circuit 25. Here, the time counting circuit 27 counts the state of the "1" level when the level of the output of the slow motion detection circuit 23 changes from "0" to "1", and the counting time is shown in FIG. As shown, it is output as an on-time signal through the buffer (FIG. 3f).

従って、以上のような実施例の構成によれば、連動検出
回路22と速動検出回路23とを設け、これら両出力状
態に基づいて所定のレベルのときに信号良否監視手段2
4で本来の信号と見なし、前記速動検出回路23の出力
が“1”レベルに変化した信号を時間計数する時間計数
回路27の出力をオン時間信号として出力するようにし
たので、本来の信号の始めの時間を正確に見い出すこと
ができ、一方、インパルス性ノイズその他のノイズ信号
等を確実に除去できる。しかも、時間計数回路27の計
数時間は応答性の速い速動検出回路24で得られたレベ
ル変化信号を時間計数したものであるので、正確なオン
時間信号を取得できる。
Therefore, according to the configuration of the embodiment as described above, the interlock detection circuit 22 and the fast motion detection circuit 23 are provided, and the signal quality monitoring means 2
4 is regarded as the original signal, and the output of the time counting circuit 27 that counts the time when the output of the fast movement detection circuit 23 changes to the "1" level is output as an on-time signal. It is possible to accurately find out the starting time of , and at the same time, it is possible to reliably remove impulsive noise and other noise signals. Moreover, since the counting time of the time counting circuit 27 is obtained by counting the level change signal obtained by the quick response detection circuit 24, an accurate on-time signal can be obtained.

なお、上記実施例はトーン信号の検出について述べたが
、ノイズを含む全般的な信号の検出に適用できることは
言うまでもない。またバッファ回路29についても同一
機能を有するものであれば特に限定するものではない。
Although the above embodiment describes the detection of tone signals, it goes without saying that the present invention can be applied to the detection of general signals including noise. Further, the buffer circuit 29 is not particularly limited as long as it has the same function.

その他、本発明はその要旨を逸脱しない範囲で種々変形
して実施できる。
In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

(発明の効果) 以上詳記したように本発明によれば、インパルス性ノイ
ズの影響を受けることなく正確に信号パターンを検出し
得る信号検出装置を提供できる。
(Effects of the Invention) As described in detail above, according to the present invention, it is possible to provide a signal detection device that can accurately detect a signal pattern without being affected by impulsive noise.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図ないし第3図は本発明に係わる信号検出装置の一
実施例を説明するために示したもので、第1図は本発明
装置の適用例を示す図、第2図は本発明に係わる信号検
出装置の一興体例を示す構成図、第3図は本発明装置の
動作を説明する波形図、第4図ないし第7図は従来装置
を説明する図である。 22・・・連動検出回路、23・・・速動検出回路、2
4・・・信号良否監視手段、25・・・論理ゲート回路
、26・・・状態監視用計数回路、27・・・時間計数
回路、29・・・バッファ回路。 出願人代理人 弁理士 鈴江武彦 第3 図 第5図 (b) 第6図
1 to 3 are shown to explain one embodiment of the signal detection device according to the present invention, FIG. 1 is a diagram showing an example of application of the device of the present invention, and FIG. FIG. 3 is a waveform diagram illustrating the operation of the device of the present invention, and FIGS. 4 to 7 are diagrams illustrating the conventional device. 22... Interlocking detection circuit, 23... Rapid motion detection circuit, 2
4... Signal quality monitoring means, 25... Logic gate circuit, 26... Status monitoring counting circuit, 27... Time counting circuit, 29... Buffer circuit. Applicant's agent Patent attorney Takehiko Suzue Figure 3 Figure 5 (b) Figure 6

Claims (1)

【特許請求の範囲】[Claims] 入力信号に重畳されるインパルス性ノイズに追従しない
応答の遅い遅動検出回路と、応答の速い速動検出回路と
、前記両検出回路の出力レベルが所定のレベル条件のと
きにノイズでない本来の入力信号が入力されたと判断す
る信号良否監視手段と、前記速動検出回路の出力レベル
が所定レベルとなったときそのレベル状態の時間を計数
し、前記信号良否監視手段から本来の信号有りの信号を
受けると前記計数時間信号を出力する時間計数手段とを
備えたことを特徴とする信号検出装置。
A slow detection circuit with a slow response that does not follow impulsive noise superimposed on the input signal, a fast detection circuit with a fast response, and an original input that is not noise when the output level of both detection circuits is at a predetermined level condition. Signal quality monitoring means for determining that a signal has been inputted; and when the output level of the fast motion detection circuit reaches a predetermined level, the time of that level state is counted, and the signal indicating that the original signal is present is outputted from the signal quality monitoring means. A signal detection device comprising: time counting means for outputting the counted time signal when received.
JP2724287A 1987-02-10 1987-02-10 Signal detector Pending JPS63196145A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2724287A JPS63196145A (en) 1987-02-10 1987-02-10 Signal detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2724287A JPS63196145A (en) 1987-02-10 1987-02-10 Signal detector

Publications (1)

Publication Number Publication Date
JPS63196145A true JPS63196145A (en) 1988-08-15

Family

ID=12215609

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2724287A Pending JPS63196145A (en) 1987-02-10 1987-02-10 Signal detector

Country Status (1)

Country Link
JP (1) JPS63196145A (en)

Similar Documents

Publication Publication Date Title
US6067353A (en) Method and apparatus for detecting a call waiting signal on a telephone line connected to a modem
US5293575A (en) Facsimile apparatus with audio response function
JPH0736580B2 (en) Phone bridge sensor
JPS63196145A (en) Signal detector
JPH04156047A (en) Facsimile equipment
US3742155A (en) Call source verification arrangement
JPS59178851A (en) Telephone set circuit
JPS63232718A (en) Radio communication system
JPS60253354A (en) Automatic telephone originating device
JP2924137B2 (en) Echo canceller control method
JP6475209B2 (en) Communication apparatus and communication control method
JP2000032245A (en) Reception signal detector and personal computer
JP3249021B2 (en) Automatic notification device
JPH06253033A (en) Data communications equipment for telephone line
KR0175379B1 (en) Handset neglect alarm device using error tone
JPS6157174A (en) Facsimile equipment
EP0427800B1 (en) Interlock circuit for preventing corruption of telephone line signals
KR940009778B1 (en) Ring-responding method of an auto-response device
JPH0243884A (en) Incoming call detection circuit
JPH027763A (en) Picture communication equipment
JPS61296894A (en) Incoming signal detecting method for telephone set
JPH06318970A (en) Calling monitoring device
JPH0591237A (en) Facsimile equipment
JPS60121871A (en) Communicating device
JPH0486093A (en) Dial pulse reception equipment