JPH0437231A - Differential transmitter - Google Patents
Differential transmitterInfo
- Publication number
- JPH0437231A JPH0437231A JP14132290A JP14132290A JPH0437231A JP H0437231 A JPH0437231 A JP H0437231A JP 14132290 A JP14132290 A JP 14132290A JP 14132290 A JP14132290 A JP 14132290A JP H0437231 A JPH0437231 A JP H0437231A
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- Prior art keywords
- signal
- phase
- output
- transmission
- phase signal
- Prior art date
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- 230000005540 biological transmission Effects 0.000 claims abstract description 100
- 238000001514 detection method Methods 0.000 claims abstract description 17
- 230000005856 abnormality Effects 0.000 claims description 26
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 230000002159 abnormal effect Effects 0.000 description 22
- 238000010586 diagram Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 3
- 238000003776 cleavage reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
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Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は、差動伝送装置、特にその差動伝送路におけ
る信号異常、短絡等の伝送路の異常等を検出する異常検
出回路を有した差動伝送装置に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a differential transmission device, particularly a differential transmission device having an abnormality detection circuit for detecting abnormalities in the transmission path such as signal abnormalities and short circuits in the differential transmission path. The present invention relates to a differential transmission device.
［従来の技術］
第３図は従来の差動伝送装置を示す接続図、第４図は正
常状態及び異常状態を第３図における各部の信号波形で
示す動作説明図で、第３図において、（１）はデータ送
信回路で、その出力伝送路（１０１）に矩形波状の出力
信号（１０１５）を出力する。[Prior Art] Fig. 3 is a connection diagram showing a conventional differential transmission device, and Fig. 4 is an operation explanatory diagram showing normal states and abnormal states by signal waveforms of each part in Fig. 3. In Fig. 3, (1) is a data transmission circuit which outputs a rectangular waveform output signal (1015) to its output transmission line (101).
（２）は前記出力信号（ＩＯＩｓ）を受信する差動ドラ
イバで、前記出力信号（１０１５）と同じＡ相信号（２
０１５）をＡ相伝送路（２０１）に送出すると共に、前
記Ａ相信号（２０１５）と逆極性のＢ相信号（２０２５
）をＢ相伝送路（２０２）に送出する。（３）は前記Ａ
相信号（２０１Ｓ）と前記Ｂ相信号（２０２５）とを受
信する差動レシーバで、これら両受信信号（２０１５）
（２０２５）から前記データ送信回路（１）の出力信
号（１０１５）を復元して出力信号（３０１５）を出力
伝送路（３０１）に出力する。（４）は前記差動レシー
バ（３）の出力信号（３０１Ｓ）を受信するデータ受信
回路、（５）は前記Ａ相信号（２０１５）及び前記Ｂ相
信号（２０２Ｓ）を入力するエクスクル−シブＯＲゲー
トで、前記Ａ相信号（２０ＬＳ）及び前記Ｂ相信号（２
０２５）が共に１の場合、及び共に０の場合のみ出力０
（伝送異常の出力）となり、他の場合は出力１（伝送正
常の出力）となる出力信号（ｓｏｔｓ）を状態伝送路（
５０１）に送出する。（６）は差動伝送路の終端抵抗で
ある。(2) is a differential driver that receives the output signals (IOIs), and is the same A-phase signal (2) as the output signal (1015).
015) to the A-phase transmission line (201), and at the same time sends the B-phase signal (2025) with the opposite polarity to the A-phase signal (2015).
) is sent to the B-phase transmission line (202). (3) is the above A
A differential receiver that receives the phase signal (201S) and the B-phase signal (2025), and receives both received signals (2015).
The output signal (1015) of the data transmission circuit (1) is restored from (2025) and the output signal (3015) is output to the output transmission path (301). (4) is a data receiving circuit that receives the output signal (301S) of the differential receiver (3), and (5) is an exclusive OR that receives the A-phase signal (2015) and the B-phase signal (202S). At the gate, the A phase signal (20LS) and the B phase signal (2
025) are both 1 and 0, the output is 0.
(transmission abnormal output), otherwise the output signal (sots) is output 1 (transmission normal output).
501). (6) is the terminating resistance of the differential transmission line.
第４図において、（イ）は前記データ送信回路（１）の
出力信号（１０１Ｓ）を、（ロ）は前記差動ドライバ（
２）の一方の出力信号であるＡ相信号（２０１５）を、
（ハ）は前記差動ドライバ（２）の他方の出力信号であ
るＢ相信号（２０２５）を、（ニ）は前記差動レシーバ
（３）の出力信号（３０１Ｓ）を、（ホ）は前記エクス
クル−シブＯＲゲート（５）の出力信号（５０１５）を
、夫々示している。（Ｔ１）は伝送が正常に行われてい
る期間、（丁２）〜（Ｔ４）は伝送が異常である期間で
、（Ｔ２）はデータ送信回路（１）の出力信号（１０１
Ｓ）と無関係に１となった場合を、（Ｔ３）はデータ送
信回路（１）の出力信号（１０１５）と無関係Ｏとなっ
た場合を、（Ｔ４）はＡ相伝送路（２０１）とＢ相伝送
路（２０２）とが短絡した場合を、夫々示している。In FIG. 4, (a) shows the output signal (101S) of the data transmitting circuit (1), and (b) shows the differential driver (101S).
The A phase signal (2015), which is one output signal of 2), is
(C) is the B-phase signal (2025) which is the other output signal of the differential driver (2), (D) is the output signal (301S) of the differential receiver (3), and (E) is the other output signal of the differential driver (2). The output signals (5015) of the exclusive OR gate (5) are shown, respectively. (T1) is a period when transmission is normally performed, (T2) to (T4) are periods when transmission is abnormal, and (T2) is an output signal (101) of data transmission circuit (1).
(T3) is the case where it becomes O regardless of the output signal (1015) of the data transmitting circuit (1), and (T4) is the case where it becomes 1 regardless of the output signal (1015) of the data transmitting circuit (1). The cases in which the phase transmission line (202) is short-circuited are shown.
次に伝送路の状態の検出を行なう動作について説明する
。Next, the operation for detecting the state of the transmission path will be explained.
伝送が正常に行われている状態（第４図の期間（丁１）
の状態）では、データ送信回路（１）は第４図（イ）に
示すようなデータ信号（１０１５）を出力伝送路（１０
１）に送出し、このデータ信号（１０１５）を受けて、
差動ドライバ（２）がＡ相伝送路（２０１）に、第４図
（ロ）に示すような前記データ信号（１０１５）と同じ
Ａ相信号（２０１５）を送出すると共に、Ｂ相伝送路（
２０２）に、第４図（ハ）に示すような前記データ信号
（１０１５）即ちＡ相信号（２０１５）と逆極性のＢ相
信号（２０２５）を送出する。これらＡ相信号（２０１
Ｓ）及びＢ相信号（２０２Ｓ）は差動レシーバ（３）に
入力され、この差動レシーバ（３）により前記データ送
信回路（１）の出力データ信号（１０１５）が復元され
出力伝送路（３０１）に出力信号（３０１５） （第４
図（ニ））として出力され、データ受信回路（４）に入
力される。一方、エクスクル−シブＯＲゲート（５）は
、その一方の入力信号（２０１５）が１で且つ他方の入
力信号（２０２５）が０であるか又は一方の入力信号（
２０１５）がＯで且つ他方の入力信号（２０２５）が１
であるので、その出力は常に１となって伝送が正常であ
ることを表わしている。State where transmission is being performed normally (period (1) in Figure 4)
state), the data transmitting circuit (1) outputs the data signal (1015) as shown in FIG.
1), and upon receiving this data signal (1015),
The differential driver (2) sends out the A-phase signal (2015), which is the same as the data signal (1015) shown in FIG.
202), the data signal (1015) as shown in FIG. 4(C), that is, the B-phase signal (2025) having the opposite polarity to the A-phase signal (2015) is sent out. These A-phase signals (201
S) and B-phase signal (202S) are input to a differential receiver (3), which restores the output data signal (1015) of the data transmission circuit (1) and sends it to the output transmission line (301). ) to the output signal (3015) (4th
The data is output as (d) in the figure and input to the data receiving circuit (4). On the other hand, the exclusive OR gate (5) has one input signal (2015) of 1 and the other input signal (2025) of 0, or one input signal (2025) of the exclusive OR gate (5).
2015) is O and the other input signal (2025) is 1
Therefore, its output is always 1, indicating that the transmission is normal.
次に、第４図の期間（Ｔ２）に示すように、Ａ相信号（
２０１Ｓ）が０となるへき時に１となっている（第４図
（ロ））異常状態の場合、エクスクル−シブＯＲゲート
（５）の入力信号（２０１５） （２０２５）が共に１
となる状態が生じ、この場合その出力（５０１Ｓ）は○
となり、伝送系が異常であることを示す出力となる。Next, as shown in period (T2) in FIG.
In the case of an abnormal state in which the signal (201S) becomes 1 when it becomes 0 (Fig. 4 (b)), the input signals (2015) and (2025) of the exclusive OR gate (5) both become 1.
In this case, the output (501S) is ○
This is an output indicating that the transmission system is abnormal.
また、第４図の期間（Ｔ３）に示すように、Ｂ相信号（
２０２Ｓ）が１となるべき時に０となっている（第４図
（ハ））異常状態の場合、エクスクル−シブＯＲゲート
（５）の入力信号（２０１Ｓ） （２０２５）は共にＯ
となる状態が生じ、この場合その出力（５０１５）はＯ
となり、伝送系が異常であることを示す出力となる。In addition, as shown in period (T3) in FIG. 4, the B-phase signal (
202S) is 0 when it should be 1 (Fig. 4 (c)), the input signals (201S) and (2025) of the exclusive OR gate (5) are both O.
A situation arises in which the output (5015) is O
This is an output indicating that the transmission system is abnormal.
第４図の期間（Ｔ４）はＡ相伝送路（２０１）及びＢ相
伝送路（２０２）が相互に短絡した場合あるいは両伝送
路（２０１）（２０２）の少なくとも一方が断線した場
合であり、この場合はエクスクル−シブＯＲゲート（５
）の入力信号（２０１５） （２０２５）の論理レベル
が不確定となり、伝送系が異常であるにも拘らず、エク
スクル−シブＯＲゲート（５）の出力は異常出力。The period (T4) in FIG. 4 is when the A-phase transmission line (201) and the B-phase transmission line (202) are short-circuited to each other, or when at least one of the transmission lines (201) and (202) is disconnected. In this case, an exclusive OR gate (5
) input signals (2015) (2025) are uncertain, and even though the transmission system is abnormal, the output of the exclusive OR gate (5) is an abnormal output.
つまり図示のようにＯとなるへきところが、正常出力、
つまり１となって誤出力する場合が生じる。In other words, as shown in the diagram, the cleavage point where the value is O is the normal output.
In other words, it may become 1 and result in an erroneous output.
［発明が解決しようとする課題］
従来の差動伝送装置は前述のように、差動ドライバ（２
）の出力信号の一方であるＡ相信号（２０１ｓ）と他方
であるＢ相信号（２０２ｓ）とをエクスクル−シブＯＲ
ゲート（５）に入力する構成することにより、伝送系の
異常を検出していたので、差動ドライバ（２）の両伝送
路（２０１） （２０２）が相互に短絡した場合あるい
は両伝送路（２０１）（２０２）の少なくとも一方が断
線した場合は、伝送系が異常であるにも拘らず。[Problem to be solved by the invention] As mentioned above, the conventional differential transmission device uses a differential driver (two
), one of the output signals of the A phase signal (201s) and the other of the output signals of the B phase signal (202s) are exclusively ORed.
By configuring the input to the gate (5), abnormalities in the transmission system were detected. If at least one of 201) and 202 is disconnected, even though the transmission system is abnormal.
エクスクル−シブＯＲゲート（５）が正常出力を出して
しまう場合が生じるという課題があった。There is a problem in that the exclusive OR gate (5) sometimes outputs a normal output.
この発明はこのような従来の課題を解決するためになさ
れたもので、前述のような差動ドライバの出力伝送路が
短絡したり断線した場合のように、差動ドライバの出力
信号のレベルが不確定な状態となった場合でも伝送系の
異常を検出することを目的とする。This invention was made in order to solve such conventional problems, and as in the case where the output transmission line of the differential driver is short-circuited or disconnected as described above, the level of the output signal of the differential driver may change. The purpose is to detect abnormalities in the transmission system even when it is in an uncertain state.
［課題を解決するための手段］
この発明に係る差動伝送装置は、データ送信回路、この
データ送信回路の出力をＡ相信号とこのＡ相信号と逆極
性のＢ相信号とに分けて送信する差動ドライバ、前記Ａ
相信号と前記Ｂ相信号とを受信しこれら両受信信号から
前記データ送信回路の出力信号を復元して出力する差動
レシーバ、この差動レシーバの出力を受けるデータ受信
回路、及び前記Ａ相信号と前記Ｂ相信号との電位差を検
出しこの電位差が所定レベルより低い場合に伝送異常と
判定する異常検出回路を備えたものである。[Means for Solving the Problems] A differential transmission device according to the present invention includes a data transmission circuit, and an output of the data transmission circuit is divided into an A-phase signal and a B-phase signal having a polarity opposite to the A-phase signal and transmitted. differential driver, said A
a differential receiver that receives a phase signal and the B-phase signal, restores and outputs the output signal of the data transmitting circuit from both received signals, a data receiving circuit that receives the output of the differential receiver, and the A-phase signal. The apparatus is equipped with an abnormality detection circuit that detects the potential difference between the signal and the B-phase signal and determines that there is a transmission abnormality when this potential difference is lower than a predetermined level.
［作 用］
この発明の差動伝送装置においては、差動ドライバの出
力、つまり差動レシーバの入力であるＡ相信号及びＢ相
信号の伝送路、即ちＡ相伝送路及びＢ相伝送路が相互に
短絡した場合あるいは実伝送路の少なくとも一方が断線
した場合、前記Ａ相信号と前記Ｂ相信号との電位差が小
さくなり、この電位差が小さくなったことを異常検出回
路が検出し、異常であることを判定、検出できる。[Function] In the differential transmission device of the present invention, the output of the differential driver, that is, the transmission line of the A-phase signal and the B-phase signal that are the input of the differential receiver, that is, the A-phase transmission line and the B-phase transmission line are If they are short-circuited to each other or if at least one of the actual transmission lines is disconnected, the potential difference between the A-phase signal and the B-phase signal becomes small, and the abnormality detection circuit detects that this potential difference has become small and detects an abnormality. Can determine and detect something.
［実施例］
第１図はこの発明の一実施例を示す接続図、第２図は正
常状態及び異常状態を第１図における各部の信号波形で
示す動作説明図で、第１図において、（１）はデータ送
信回路で、その出力伝送路（１０１）に矩形波状の出力
信号（１０１５）を出力する。[Embodiment] Fig. 1 is a connection diagram showing an embodiment of the present invention, and Fig. 2 is an operation explanatory diagram showing normal and abnormal states by signal waveforms of each part in Fig. 1. In Fig. 1, ( 1) is a data transmission circuit which outputs a rectangular waveform output signal (1015) to its output transmission line (101).
（２）は前記出力信号（ｌｏｔｓ）を受信する差動ドラ
イバで、前記出力信号（１０１５）と同じＡ相信号（２
０１５）をＡ相伝送路（２（Ｈ）に送出すると共に、前
記Ａ相信号（２０１Ｓ）と逆極性のＢ相信号（２０２５
）をＢ相伝送路（２０２）に送出する。（３）は前記Ａ
相信号（２０１５）と前記Ｂ相信号（２０２５）とを受
信する差動レシーバで、これら両受信信号（２０１Ｓ）
（２０２Ｓ）から前記データ送信回路（１）の出力信
号（１０１５）を復元して出力信号（３０１５）を出力
伝送路（３０１）に出力する。（４）は前記差動レシー
バ（３）の出力信号（３０１５）を受信するデータ受信
回路、（７Ａ） （７Ｂ） （８Ａ） （８Ｂ）は抵抗
、（９Ａ）（９Ｂ）はフォトカプラ、（１０）はＮＡＮ
Ｄゲート、（１１）は異常検出回路で、前記抵抗（７Ａ
） （７Ｂ） （８Ａ）（８Ｂ）とフォトカプラ（９Ａ
） （９Ｂ）とＮＡＮＤゲート（１０）とで構成されて
いる。（１１１） （１１２）は異常検出回路（１１）
のＡ相及びＢ相入力信号線で、Ａ相入力信号線（１１１
）の一端はＡ相伝送路（２０１）に接続され、他端は抵
抗（７Ａ）を介してフォトカプラ（９Ａ）の発光ダイオ
ードのアノード及びフォトカプラ（９Ｂ）の発光ダイオ
ードのカソードに接続されており、Ｂ相入力信号線（１
１２）の一端はＢ相伝送路（２０２）に接続され、他端
は抵抗（７Ｂ）を介してフォトカプラ（９Ｂ）の発光ダ
イオードのアノード及びフォトカプラ（９Ａ）の発光ダ
イオードのカソードに接続されている。（１１３）はＮ
ＡＮＤゲート（１０）の出力信号線で。(2) is a differential driver that receives the output signal (lots), and is the same A-phase signal (2) as the output signal (1015).
015) to the A-phase transmission line (2(H)), and at the same time sends the B-phase signal (2025) with the opposite polarity to the A-phase signal (201S).
) is sent to the B-phase transmission line (202). (3) is the above A
A differential receiver that receives the phase signal (2015) and the B-phase signal (2025), and receives both of these received signals (201S).
The output signal (1015) of the data transmission circuit (1) is restored from (202S) and the output signal (3015) is output to the output transmission path (301). (4) is a data receiving circuit that receives the output signal (3015) of the differential receiver (3), (7A) (7B) (8A) (8B) is a resistor, (9A) (9B) is a photocoupler, ( 10) is NAN
D gate (11) is an abnormality detection circuit, and the resistor (7A
) (7B) (8A) (8B) and photocoupler (9A
) (9B) and a NAND gate (10). (111) (112) is an abnormality detection circuit (11)
The A-phase and B-phase input signal lines of the A-phase input signal line (111
) is connected to the A-phase transmission line (201), and the other end is connected to the anode of the light emitting diode of the photocoupler (9A) and the cathode of the light emitting diode of the photocoupler (9B) via a resistor (7A). B-phase input signal line (1
12) One end is connected to the B-phase transmission line (202), and the other end is connected to the anode of the light emitting diode of the photocoupler (9B) and the cathode of the light emitting diode of the photocoupler (9A) via a resistor (7B). ing. (113) is N
On the output signal line of the AND gate (10).
異常検出回路（１）の出力信号線でもある。前記フォト
カプラ（９Ａ）は、Ａ相信号（２０１５）の電位がＢ相
信号（２０２５）の電位より成る値以上大きくなると、
その発光ダイオードに抵抗（７Ａ）を通して成る値以上
の大きさの電流が流れ、ＯＮ状態になる。前記フォトカ
プラ（９Ｂ）は、Ｂ相信号（２０２５）の電位がＡ相信
号（２０１５）の電位より成る値以上大きくなると、そ
の発光ダイオードに抵抗（７Ｂ）を通して成る値以上の
大きさの電流が流れ、ＯＮ状態になる。前記ＮＡＮＤゲ
ート（１０）はその入力信号（９ＡＳ） （９ＢＳ）（
即ちフォトカプラ（９Ａ）（９Ｂ）の出力信号）の両方
が論理値１のとき（フォトカプラ（９Ａ） （９Ｂ）の
両方がＯＦＦのとき）、論理値Ｏの信号（異常を示す信
号）を出力するものである。It is also the output signal line of the abnormality detection circuit (1). The photocoupler (9A) detects that when the potential of the A-phase signal (2015) becomes larger than the potential of the B-phase signal (2025),
A current larger than the value formed by the resistor (7A) flows through the light emitting diode, and the light emitting diode becomes in an ON state. When the potential of the B-phase signal (2025) becomes larger than the potential of the A-phase signal (2015), the photocoupler (9B) generates a current greater than the value formed through the light emitting diode through the resistor (7B). flows and becomes ON state. The NAND gate (10) receives its input signals (9AS) (9BS) (
In other words, when both the output signals of photocouplers (9A) and (9B) have a logic value of 1 (when both photocouplers (9A) and (9B) are OFF), a signal with a logic value of O (a signal indicating an abnormality) is output. This is what is output.
第２図において、（イ）は前記データ送信回路（１）の
出力信号（１０１５）を、（ロ）は前記差動ドライバ（
２）の一方の出力信号であるＡ相信号（２０１５）を、
（ハ）は前記差動ドライバ（２）の他方の出力であるＢ
相信号（２０２５）を、（ニ）は前記差動レシーバ（３
）の出力信号（３０１５）を、（ホ）は前記フォトカプ
ラ（９Ａ）の出力信号、即ち前記ＮＡＮＤゲー）−（１
０）の一方の入力信号（９ＡＳ）を、（へ）は前記フォ
トカプラ（９Ｂ）の出力信号、即ち前記ＮＡＮＤゲート
（１０）の他方の入力信号（９ＢＳ）を、（ト）は前記
ＮＡＮＤゲート（１０）の出力信号、即ち前記異常検出
回路（１１）の出力信号（１００Ｓ）を、夫々示してい
る。（Ｔｌ）は差動ドライバ（２）から差動レシーバ（
３）への伝送が正常に行われている期間、（Ｔ４）〜（
Ｔｌ）は差動ドライバ（２）から差動レシーバ（３）へ
の伝送が異常である期間で、（Ｔ４）は前記Ａ相伝送路
（２０１）と前記Ｂ相伝送路（２０２）とが短絡した場
合を、（Ｔ５）は前記Ａ相伝送路（２０１）が断線した
場合を、（Ｔ６）は前記Ｂ相伝送路（２０２）が断線し
た場合を、（Ｔ７）は前記Ａ相伝送路（２０１）がアー
ス短絡した場合を、夫々示している。In FIG. 2, (a) shows the output signal (1015) of the data transmitting circuit (1), and (b) shows the differential driver (1015).
The A phase signal (2015), which is one output signal of 2), is
(C) is the other output of the differential driver (2) B
phase signal (2025), (d) is the differential receiver (3)
) is the output signal (3015) of the photocoupler (9A), (e) is the output signal of the photocoupler (9A), that is, the NAND game) - (1
0), one input signal (9AS) of the photocoupler (9B), (g) the output signal of the photocoupler (9B), that is, the other input signal (9BS) of the NAND gate (10), and (g) the NAND gate The output signals of (10), that is, the output signals (100S) of the abnormality detection circuit (11) are shown, respectively. (Tl) is from the differential driver (2) to the differential receiver (
3) during which transmission to (T4) to (T4) is normally performed.
Tl) is the period when the transmission from the differential driver (2) to the differential receiver (3) is abnormal, and (T4) is the period when the A-phase transmission line (201) and the B-phase transmission line (202) are short-circuited. (T5) is the case where the A-phase transmission line (201) is disconnected, (T6) is the case where the B-phase transmission line (202) is disconnected, and (T7) is the case where the A-phase transmission line (201) is disconnected. 201) is short-circuited to ground.
次に伝送路の状態の検出を行なう動作について説明する
。Next, the operation for detecting the state of the transmission path will be explained.
伝送が正常に行われている状態（第２図の期間（ＴＩ）
の状Ｓ）では、データ送信回路（１）は第２図（イ）に
示すようなデータ信号（１０１５）を出力伝送路（１０
１）に送出し、このデータ信号（１０１５）を受けて、
差動ドライバ（２）がＡ相伝送路（２０１）に、第２図
（ロ）に示すような前記データ信号（１０１５）と同じ
極性のＡ相信号（２０１５）を送出すると共に、Ｂ相伝
送路（２０２）に、第２図（ハ）に示すような前記デー
タ信号（１０１５）即ちＡ相信号（２０１ｓ）と逆極性
のＢ相信号（２０２Ｓ）を送出する。これらＡ相信号（
２０１５）及びＢ相信号（２０２５）は差動レシーバ（
３）に入力され、この差動レシーバ（３）により前記デ
ータ送信回路（１）の出力データ信号（１０１ｓ）が復
元され出方伝送路（３０１）に出力信号（３０１Ｓ）
（第２図（ニ））として出力され、データ受信回路（４
）に入力される。一方。State where transmission is being performed normally (period (TI) in Figure 2)
In the state S), the data transmission circuit (1) sends the data signal (1015) as shown in FIG. 2(A) to the output transmission line (10
1), and upon receiving this data signal (1015),
The differential driver (2) sends out an A-phase signal (2015) having the same polarity as the data signal (1015) as shown in FIG. The data signal (1015) as shown in FIG. 2(C), that is, the B-phase signal (202S) having the opposite polarity to the A-phase signal (201s) is sent to the channel (202). These A-phase signals (
2015) and B-phase signal (2025) are sent to the differential receiver (
3), the differential receiver (3) restores the output data signal (101s) of the data transmission circuit (1), and outputs the output signal (301S) to the output transmission line (301).
(Figure 2 (d)), and the data receiving circuit (4)
) is entered. on the other hand.
フォトカプラ（９Ａ）は、Ａ相信号（２０１５）が１で
Ｂ相信号（２０２５）がＯの状態のときにＯＮとなり、
その出力信号（９ＡＳ）はアース電位の０となり、逆に
Ａ相信号（２０１５）がＯでＢ相信号（２０２５）が１
の状態のときにＯＦＦとなり、その出力信号（９ＡＳ）
は１となっている。フォトカプラ（９Ｂ）は、前述のフ
ォトカプラ（９Ａ）の動作とは逆に、Ａ相信号（２０１
５）が１でＢ相信号（２０２５）が○の状態のときにＯ
ＦＦとなっており、その出力信号（９ＢＳ）はｌとなり
、逆にＡ相信号（２０１Ｓ）がＯでＢ相信号（２０２５
）が１の状態のときにＯＮとなって、その出力信号（９
ＢＳ）はアース電位のＯとなっている。つまり、フォト
カプラ（９Ａ）（９Ｂ）ノ出力信号（９ＡＳ） （９Ｂ
Ｓ）は、それらの−方が１のときに他方が０、一方が０
のときに他方が１となっている。従ってこれら出力信号
（９ＡＳ）（９ＢＳ）が入力されるＮＡＮＤゲート（ｌ
ｏ）ノ出方信号、つまり異常検出回路（１１）の出方信
号（１００Ｓ）は出力１の状態が維持されており、伝送
が正常に行われていることを表わしている。The photocoupler (9A) turns ON when the A phase signal (2015) is 1 and the B phase signal (2025) is O.
The output signal (9AS) is 0 at ground potential, and conversely, the A phase signal (2015) is O and the B phase signal (2025) is 1.
It turns OFF in the state of , and its output signal (9AS)
is 1. Opposite to the operation of the photocoupler (9A) described above, the photocoupler (9B) receives the A-phase signal (201
5) is 1 and the B phase signal (2025) is O.
The output signal (9BS) is 1, and conversely, the A phase signal (201S) is O and the B phase signal (2025
) is turned on when it is in the state of 1, and its output signal (9
BS) is O at ground potential. In other words, the photocoupler (9A) (9B) output signal (9AS) (9B
S), when the - one of them is 1, the other is 0, and one is 0
When , the other one becomes 1. Therefore, these output signals (9AS) (9BS) are input to the NAND gate (l
o) The output signal (100S) of the abnormality detection circuit (11) maintains the output 1 state, indicating that the transmission is being performed normally.
次に、第２図の期間（Ｔ５）に示すように、Ａ相伝送路
（２０＋）が断線した場合には、フォトカプラ（９Ａ）
（９Ｂ）は、それらの発光ダイオードには所定値以上の
電圧がかからなくなるため、双方共にＯＦＦの状態とな
り、従って両フォトカプラ（９Ａ）（９Ｂ）の出力信号
（９ＡＳ）（９ＢＳ）は何れも１の状態となる（第２図
（ホ）（へ））ので、ＮＡＮＤゲート（１０）の出力、
即ち異常検出回路（１１）の出力信号（１００５）は０
の状態（第２図（ト））となり、伝送が異常であること
を表わす。Next, as shown in period (T5) in Figure 2, when the A-phase transmission line (20+) is disconnected, the photocoupler (9A)
(9B) is no longer applied with a voltage higher than a predetermined value to those light emitting diodes, so both are in the OFF state, so the output signals (9AS) (9BS) of both photocouplers (9A) (9B) are is also in the state of 1 (Fig. 2 (E) and (E)), so the output of the NAND gate (10),
That is, the output signal (1005) of the abnormality detection circuit (11) is 0.
(FIG. 2 (G)), indicating that the transmission is abnormal.
第２図の期間（Ｔ６）はＢ相伝送路（２０２）が断線し
た場合であるが、この場合は、前述のＡ相伝送路（２０
１）断線の場合と同様の動作となり、第２図（ホ）（へ
）に示すように、両フォトカプラ（９Ａ） （９Ｂ）の
出力信号（９ＡＳ） （９ＢＳ）の何れも１の状態とな
り、異常検出回路（１工）の出力信号（１００５）はＯ
の状態（第２図（ト））となり、伝送が異常であること
を表わす。The period (T6) in FIG. 2 is when the B-phase transmission line (202) is disconnected, but in this case, the above-mentioned A-phase transmission line (202) is disconnected.
1) The operation is the same as in the case of a disconnection, and as shown in Figure 2 (E) and (F), the output signals (9AS) (9BS) of both photocouplers (9A) (9B) become 1. , the output signal (1005) of the abnormality detection circuit (1st construction) is O.
(FIG. 2 (g)), indicating that the transmission is abnormal.
第２図の期間（Ｔ７）は、Ａ相伝送路（２０１）がアー
ス短絡した場合を示しており、Ａ相伝送路（２０１）の
Ａ相信号（２０１５）は継続的に０となり、Ｂ相信号（
２０２５）は出力データ信号（１０１５）に逆極性で対
応して交互に１、○となる。従って、Ｂ相信号（２０２
５）がＯとなってＡ相信号（２０１５）とＢ相信号（２
０２５） トが共にＯのときにフォトカプラ（９Ａ）
（９Ｂ）の出力信号（ＮＡＮＤゲート（１０）の入力信
号）が共に１となって異常検出回路（１１）の出力がＯ
となり、異常状態であることを表わす。The period (T7) in Figure 2 shows the case where the A-phase transmission line (201) is shorted to ground, and the A-phase signal (2015) of the A-phase transmission line (201) is continuously 0, and the B-phase signal (2015) of the A-phase transmission line (201) is continuously 0. signal(
2025) corresponds to the output data signal (1015) with opposite polarity and becomes 1 and ◯ alternately. Therefore, the B phase signal (202
5) becomes O, and the A phase signal (2015) and B phase signal (2015)
025) Photocoupler (9A) when both
(9B) output signals (input signals of NAND gate (10)) both become 1, and the output of abnormality detection circuit (11) becomes O.
This indicates an abnormal state.
第２図の期間（丁４）は、Ａ相伝送路（２０１）とＢ相
伝送路（２０２＞とが短絡した場合を示しており、フォ
トカプラ（９Ａ） （９Ｂ）は、それらの発光ダイオー
ドには所定値以上の電圧がかがらないため、双方共にＯ
ＦＦの状態となり、従ってＮＡＮＤゲート（１０）の出
力、即ち異常検出回路（１１）の出力信号（１００５）
はＯの状態となり、異常であることを表わす。The period (4) in Fig. 2 shows the case where the A-phase transmission line (201) and the B-phase transmission line (202> are short-circuited, and the photocouplers (9A) (9B) are connected to their light emitting diodes. Since the voltage above the specified value is not applied to the
FF state, therefore, the output of the NAND gate (10), that is, the output signal (1005) of the abnormality detection circuit (11)
is in the O state, indicating an abnormality.
なお、第２図に図示してないが、Ａ相信号（２０１５）
のみ１の状態が継続するような異常状態。Although not shown in Fig. 2, the A phase signal (2015)
An abnormal condition in which the condition 1 continues.
Ｂ相信号（２０２５）のみＯの状態が継続するような異
常状態、Ａ相信号（２０１５）及びＢ相信号（２０２５
）（７）双方が共に１あるいは共にＯとなるような異常
状態等、前述の具体例以外の異常状態をも検出できる。An abnormal state in which only the B-phase signal (2025) remains O, the A-phase signal (2015) and the B-phase signal (2025)
) (7) It is also possible to detect abnormal states other than the above-mentioned specific example, such as an abnormal state where both are 1 or both are O.
また、前述の実施例においてはＡ相伝送路（２０１）と
Ｂ相伝送路（２０２）との電位差を検出する手段として
フォトカプラ（９Ａ） （９Ｂ）を使用した例を示した
が、○Ｐアンプ等、他の手段を使用しても前述の実施例
と同様の効果を奏する。In addition, in the above embodiment, an example was shown in which photocouplers (9A) (9B) were used as means for detecting the potential difference between the A-phase transmission line (201) and the B-phase transmission line (202), but ○P Even if other means such as an amplifier are used, the same effect as in the above-described embodiment can be obtained.
Ｃ発明の効果］
この発明は前述のように、データ送信回路と、このデー
タ送信回路の出力をＡ相信号とこのＡ相信号と逆極性の
Ｂ相信号とに分けて送信する差動ドライバと、前記Ａ相
信号と前記Ｂ相信号とを受信しこれら両受倍信号から前
記データ送信回路の出力信号を復元して出力する差動レ
シーバと、この差動レシーバの出力を受けるデータ受信
回路と、前記Ａ相信号と前記Ｂ相信号との電位差を検出
しこの電位差が所定レベルより低い場合に伝送異常と判
定する異常検出回路とを備えた構成としたので、従来の
装置では確実には検出することができなかった異常状態
、即ちＡ相伝送路及びＢ相伝送路の少なくと一方が断線
した場合や、Ａ相伝送路とＢ相伝送路とが短絡した場合
のように、伝送路における伝送信号がデータ送信回路の
出力データ信号とモードは同じであるが信号レベルが低
くなるような異常状態をも確実に検出できる効果がある
。C Effects of the Invention] As described above, the present invention includes a data transmitting circuit, a differential driver that divides the output of the data transmitting circuit into an A-phase signal and a B-phase signal having the opposite polarity to the A-phase signal, and transmits the output. , a differential receiver that receives the A-phase signal and the B-phase signal, restores and outputs the output signal of the data transmitting circuit from these multiplied signals, and a data receiving circuit that receives the output of the differential receiver. , an abnormality detection circuit that detects the potential difference between the A-phase signal and the B-phase signal and determines that there is a transmission abnormality when this potential difference is lower than a predetermined level. Abnormal conditions in the transmission line, such as when at least one of the A-phase transmission line and B-phase transmission line is disconnected, or when the A-phase transmission line and the B-phase transmission line are short-circuited, This has the effect of reliably detecting an abnormal state in which the transmission signal is in the same mode as the output data signal of the data transmission circuit but the signal level is low.
第１図はこの発明の一実施例を示す接続図、第２図は正
常状態及び異常状態を第１図における各部の信号波形で
示す動作説明図、第３図は従来の差動伝送装置を示す接
続図、第４図は正常状態及び異常状態を第３図における
各部の信号波形で示す動作説明図である。
図において、（１）はデータ送信回路、（２）は差動ド
ライバ、（３）は差動レシーバ、（４）はデータ受信回
路、（１１）は異常検出回路、 （１００Ｓ）は異常検
出回路（１１）の出力信号、（１０１５）はデータ送信
回路（１）の出力データ信号、（２０１）はＡ相伝送路
、（７０１５）はＡ相信号、（２０２）はＢ相伝送路、
（２０２５）はＢ相信号である。
なお図中同一符号は同−又は相当部分を示す。
−一一二
’、ｉ４’ｈFig. 1 is a connection diagram showing an embodiment of the present invention, Fig. 2 is an operation explanatory diagram showing normal and abnormal states with signal waveforms of each part in Fig. 1, and Fig. 3 is a diagram showing a conventional differential transmission device. The connection diagram shown in FIG. 4 is an operation explanatory diagram showing the normal state and abnormal state by signal waveforms of each part in FIG. 3. In the figure, (1) is a data transmission circuit, (2) is a differential driver, (3) is a differential receiver, (4) is a data reception circuit, (11) is an abnormality detection circuit, and (100S) is an abnormality detection circuit. (11) is the output signal, (1015) is the output data signal of the data transmission circuit (1), (201) is the A-phase transmission line, (7015) is the A-phase signal, (202) is the B-phase transmission line,
(2025) is a B-phase signal. Note that the same reference numerals in the figures indicate the same or equivalent parts. -112', i4'h
Claims (1)
とこのＡ相信号と逆極性のＢ相信号とに分けて送信する
差動ドライバ、前記Ａ相信号と前記Ｂ相信号とを受信し
これら両受信信号から前記データ送信回路の出力信号を
復元して出力する差動レシーバ、この差動レシーバの出
力を受けるデータ受信回路、及び前記Ａ相信号と前記Ｂ
相信号との電位差を検出しこの電位差が所定レベルより
低い場合に伝送異常と判定する異常検出回路を備えた差
動伝送装置。a data transmitting circuit; a differential driver that divides and transmits the output of the data transmitting circuit into an A-phase signal and a B-phase signal having the opposite polarity; a differential driver that receives the A-phase signal and the B-phase signal; a differential receiver that restores and outputs the output signal of the data transmitting circuit from both received signals, a data receiving circuit that receives the output of this differential receiver, and the A-phase signal and the B-phase signal.
A differential transmission device that includes an abnormality detection circuit that detects a potential difference with a phase signal and determines a transmission abnormality when this potential difference is lower than a predetermined level.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14132290A JPH0437231A (en) | 1990-06-01 | 1990-06-01 | Differential transmitter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14132290A JPH0437231A (en) | 1990-06-01 | 1990-06-01 | Differential transmitter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0437231A true JPH0437231A (en) | 1992-02-07 |
Family
ID=15289227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14132290A Pending JPH0437231A (en) | 1990-06-01 | 1990-06-01 | Differential transmitter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0437231A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4344238A1 (en) * | 1992-12-25 | 1994-06-30 | Mitsubishi Electric Corp | Two-line input / output device |
| JP2010213246A (en) * | 2009-03-12 | 2010-09-24 | Ricoh Co Ltd | Receiving device, driver, and image forming apparatus |
| JP2011206948A (en) * | 2010-03-29 | 2011-10-20 | Canon Inc | Image forming apparatus |
-
1990
- 1990-06-01 JP JP14132290A patent/JPH0437231A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4344238A1 (en) * | 1992-12-25 | 1994-06-30 | Mitsubishi Electric Corp | Two-line input / output device |
| JP2010213246A (en) * | 2009-03-12 | 2010-09-24 | Ricoh Co Ltd | Receiving device, driver, and image forming apparatus |
| US8654166B2 (en) | 2009-03-12 | 2014-02-18 | Ricoh Company, Ltd. | Receiving device, driving unit, and image forming apparatus |
| JP2011206948A (en) * | 2010-03-29 | 2011-10-20 | Canon Inc | Image forming apparatus |
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