JPS6399641A - Bidirectional communication equipment - Google Patents
Bidirectional communication equipmentInfo
- Publication number
- JPS6399641A JPS6399641A JP24641886A JP24641886A JPS6399641A JP S6399641 A JPS6399641 A JP S6399641A JP 24641886 A JP24641886 A JP 24641886A JP 24641886 A JP24641886 A JP 24641886A JP S6399641 A JPS6399641 A JP S6399641A
- Authority
- JP
- Japan
- Prior art keywords
- equalizing amplifier
- input
- offset voltage
- canceling
- period
- 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
Links
- 230000007175 bidirectional communication Effects 0.000 title description 2
- 230000005540 biological transmission Effects 0.000 claims abstract description 23
- 230000006854 communication Effects 0.000 claims description 8
- 238000004891 communication Methods 0.000 claims description 8
- 230000004069 differentiation Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- Bidirectional Digital Transmission (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、二線式時分割双方向通信装置におけるオフセ
ント打消し回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an offset cancellation circuit in a two-wire time-division bidirectional communication device.
本発明は、伝送路を送信期間および受信期間に時分割し
て信号を授受する送信手段および受信手段を有する双方
向通信装置において、
受信時に、送信時に発生ずるオフセット電圧を打消して
等化増幅器に入力することにより、オフセット電圧の微
分により生ずる信号の発生を抑止することができるよう
にしたものである。The present invention provides a two-way communication device having a transmitting means and a receiving means for transmitting and receiving signals by time-divisionally transmitting and receiving signals on a transmission path. By inputting the offset voltage to the offset voltage, it is possible to suppress the generation of a signal caused by the differentiation of the offset voltage.
二線式時分割双方向通信装置は、二線を時間的に送信期
間および受信期間の2つに分割して双方向通信を行う装
置である。A two-wire time-division two-way communication device is a device that performs two-way communication by temporally dividing two wires into two periods, a transmission period and a reception period.
第3図にこの通信装置の従来例の構成を示す。FIG. 3 shows the configuration of a conventional example of this communication device.
この従来例装置は、入出力端子1と、送信ドライバ2と
、送信トランス3と、受信トランス4と、等化増幅器入
力短絡用のスイッチ5と、等化増幅器切り離し用のスイ
ッチ6と、等化増幅器7と、送信ドライバ入力端子1z
と、等化増幅器の出力端子11□とを備える。This conventional device includes an input/output terminal 1, a transmitting driver 2, a transmitting transformer 3, a receiving transformer 4, a switch 5 for shorting the equalizing amplifier input, a switch 6 for disconnecting the equalizing amplifier, and an equalizing amplifier. Amplifier 7 and transmission driver input terminal 1z
and an output terminal 11□ of an equalizing amplifier.
第4図はこの従来例装置の各部の信号波形を示す。送信
期間Ttには、等化増幅器7の入力に大振幅の信号入力
が加わらないようにスイッチ5は短絡され、かつスイッ
チ6は開放される。ここで、送信出力S1.のプラスの
振幅とマイナスの振幅とにアンバランスがあると、等化
増幅器70人力に直流のオフセット電圧が発生する。次
に、受信期間T1になると、スイッチ5が開放され、か
つスイッチ6が短絡される。伝送路9の高域伝送損失を
補償するため等化増幅器7の高域の利得を高めているの
で、等化増幅器7の出力信号S3は等化増幅器7の入力
信号S2の波形を微分した波形になる。FIG. 4 shows signal waveforms at various parts of this conventional device. During the transmission period Tt, the switch 5 is short-circuited and the switch 6 is opened so that a large-amplitude signal input is not applied to the input of the equalization amplifier 7. Here, transmission output S1. If there is an imbalance between the positive amplitude and the negative amplitude, a DC offset voltage will occur in the equalizing amplifier 70. Next, in the reception period T1, the switch 5 is opened and the switch 6 is short-circuited. Since the high-frequency gain of the equalizing amplifier 7 is increased to compensate for the high-frequency transmission loss of the transmission line 9, the output signal S3 of the equalizing amplifier 7 has a waveform obtained by differentiating the waveform of the input signal S2 of the equalizing amplifier 7. become.
このような従来例装置では、入力での直流オフセット電
圧と入力信号との振幅が同程度になると、等化増幅器の
出力では直流オフセット電圧による微分波形と入力信号
との区別がつかなくなり、データ誤りが生ずる欠点があ
る。In such conventional devices, when the DC offset voltage at the input and the input signal have the same amplitude, the output of the equalizing amplifier cannot distinguish between the differential waveform due to the DC offset voltage and the input signal, resulting in data errors. There is a drawback that this occurs.
本発明はこのような欠点を除去するもので、出力側から
の直流オフセット電圧の影響をうけない双方向通信装置
を提供することを目的とする。The present invention aims to eliminate such drawbacks and provides a two-way communication device that is not affected by DC offset voltage from the output side.
本発明は、二線式伝送路に接続され、送信期間に信号を
送出する送出手段と、受信期間に上記伝送路に接続され
る等化増幅器を経由して到来する信号を受信する受信手
段とを備えた双方向通信装置において、上記等化増幅器
の人力に、上記送信手段から送出される信号にかかわる
オフセット電圧を打消す打消手段を備えたことを特徴と
する。The present invention includes a sending means connected to a two-wire transmission line and sending out a signal during a transmission period, and a receiving means connected to the transmission line during a reception period receiving a signal arriving via an equalizing amplifier. The two-way communication device is characterized in that the equalizing amplifier is equipped with canceling means for canceling an offset voltage related to the signal sent from the transmitting means.
上記打消手段は、上記等化増幅器の入力を短絡するスイ
ッチであってもよい。The canceling means may be a switch that shorts the input of the equalizing amplifier.
送信期間の終了時から受信信号の到来時までの期間に、
送信出力の振幅の不平衡に基づくオフセット電圧を打消
し、放電する。この期間後に、受信を行う。During the period from the end of the transmission period to the arrival of the received signal,
The offset voltage caused by the unbalanced amplitude of the transmitted output is canceled and discharged. After this period, reception is performed.
これにより、オフセット電圧による階段波形が消去され
、等化増幅器の出力にこの階段波形を微分した信号が出
現することを抑止することができる。As a result, the staircase waveform caused by the offset voltage is erased, and it is possible to prevent a signal obtained by differentiating the staircase waveform from appearing in the output of the equalizing amplifier.
以下、本発明の一実施例を図面に基づいて説明する。 Hereinafter, one embodiment of the present invention will be described based on the drawings.
第1図はこの実施例の構成を示すブロックの構成図であ
る。第2図はこの実施例の動作を示す波形図である。な
お、第1図および第2図を通じて同一符号は同一対象を
示す。FIG. 1 is a block diagram showing the configuration of this embodiment. FIG. 2 is a waveform diagram showing the operation of this embodiment. Note that the same reference numerals indicate the same objects throughout FIG. 1 and FIG. 2.
まず、この実施例の構成を第1図に基づいて説明する。First, the configuration of this embodiment will be explained based on FIG.
この実施例は、第3図に示す従来例にオフセント・デス
チャージ用のスイッチ8が付加されたことを特徴とする
。This embodiment is characterized in that an off-cent discharge switch 8 is added to the conventional example shown in FIG.
次に、このスイッチ8の動作を説明する。送信期間T、
の終わりから人力信号S2が来るまでの間にオフセント
・デスチャージ期間T、を設ける。Next, the operation of this switch 8 will be explained. Transmission period T,
An off-cent discharge period T is provided between the end of the process and the arrival of the human power signal S2.
このオフセント・デスチャージ期間T4にオフセット・
デスチャージ用のスイッチ8を短絡して、入力オフセン
ト電圧をデスチャージする。スイッチ8の起動は送信状
態から受信状態への切り換えと同時に連動して行われる
。オフセット・デスチャージ期間Tdが終わるとスイッ
チ8は解放される。この場合は受信期間T、であり、ス
イッチ6は短絡されかつスイッチ5は開放されているの
で、等化増幅器7の入力信号S2には第4歯に示す階段
波形が見られなくなり、等化増幅器7の出力信号S3は
これによる微分波形を含まない。Offset in this offset death period T4
The discharge switch 8 is short-circuited to discharge the input off-cent voltage. Activation of the switch 8 is performed simultaneously and in conjunction with switching from the transmitting state to the receiving state. When the offset discharge period Td ends, the switch 8 is released. In this case, it is the receiving period T, and the switch 6 is short-circuited and the switch 5 is open, so that the input signal S2 of the equalizing amplifier 7 does not have the staircase waveform shown in the fourth tooth, and the equalizing amplifier The output signal S3 of No. 7 does not include a differential waveform due to this.
本発明は以上説明したように、送信期間の終わりから受
信期間の初めにオフセット打消し動作を行うので、入力
信号と区別がつかないオフセット電圧にかかわる微分波
形の発生を抑止することができる効果がある。As explained above, the present invention performs the offset cancellation operation from the end of the transmission period to the beginning of the reception period, so that it is possible to suppress the generation of a differential waveform related to the offset voltage that is indistinguishable from the input signal. be.
【図面の簡単な説明】
第1図は本発明実施例装置の構成を示す回路接続図。
第2図は本発明実施例装置の動作を説明するりイミング
チャー+−。
第3図は従来例装置の構成を示す回路接続図。
第4図は従来装置の動作を説明するタイミングチャート
。
1・・・人出力端了、2・・・送信ドライバ、3・・・
送信1−’、>7ス、4・・・受信トランス、5.6.
8・・・スイッチ、7・・・等化増幅器。
実施例の構成
第1図
実施例の動作
第2図
従来例の構成
第3図BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit connection diagram showing the configuration of an apparatus according to an embodiment of the present invention. FIG. 2 is an imaging chart for explaining the operation of the apparatus according to the embodiment of the present invention. FIG. 3 is a circuit connection diagram showing the configuration of a conventional device. FIG. 4 is a timing chart explaining the operation of the conventional device. 1... Human output terminal completed, 2... Transmission driver, 3...
Transmission 1-', >7 steps, 4...Reception transformer, 5.6.
8...Switch, 7...Equalizing amplifier. Structure of the embodiment Fig. 1 Operation of the embodiment Fig. 2 Structure of the conventional example Fig. 3
Claims (2)
する送出手段と、 受信期間に上記伝送路に接続される等化増幅器を経由し
て到来する信号を受信する受信手段とを備えた双方向通
信装置において、 上記等化増幅器の入力に、上記送信手段から送出される
信号にかかわるオフセット電圧を打消す打消手段 を備えたことを特徴とする双方向通信装置。(1) A sending means connected to a two-wire transmission line and transmitting a signal during a transmission period, and a receiving means connected to the transmission line during a reception period and receiving a signal arriving via an equalizing amplifier. A two-way communication device comprising: a canceling means for canceling an offset voltage related to a signal sent from the transmitting means at an input of the equalizing amplifier.
チである特許請求の範囲第(1)項に記載の双方向通信
装置。(2) The two-way communication device according to claim (1), wherein the canceling means is a switch that short-circuits the input of the equalizing amplifier.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24641886A JPS6399641A (en) | 1986-10-15 | 1986-10-15 | Bidirectional communication equipment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP24641886A JPS6399641A (en) | 1986-10-15 | 1986-10-15 | Bidirectional communication equipment |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6399641A true JPS6399641A (en) | 1988-04-30 |
Family
ID=17148185
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP24641886A Pending JPS6399641A (en) | 1986-10-15 | 1986-10-15 | Bidirectional communication equipment |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6399641A (en) |
-
1986
- 1986-10-15 JP JP24641886A patent/JPS6399641A/en active Pending
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