JP3543625B2

JP3543625B2 - Signal transmission device and signal transmission method using the same

Info

Publication number: JP3543625B2
Application number: JP18213798A
Authority: JP
Inventors: 良二井上; 功二鎌房
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 1998-06-29
Filing date: 1998-06-29
Publication date: 2004-07-14
Anticipated expiration: 2018-06-29
Also published as: JP2000022763A

Description

【０００１】
【発明の属する技術分野】
この発明は、少なくとも２以上の制御ユニットの間で信号伝送を行う信号伝送装置に関し、特に信号の無極化を行う信号伝送装置に係る。
【０００２】
【従来の技術】
従来より、例えば空気調和装置において、リモートコントロール器（以下「リモコン」と略称する）、室内機及び室外機の間の信号伝送方式に２本の信号線を用いた平衡通信方式が採用されているものがある（特開平５−２２７５６８号公報等）。
【０００３】
この空気調和機において、２本の信号線のそれぞれには互いに逆の極性が割り当てられる。そして、プラグ接続時の誤接続等によって極性を正逆反対に接続してしまうことがしばしばあるため、このような正逆反対の接続を許容した上で、通信時に受信側の信号伝送装置において極性判定を行い、自動的に送受信ポートの極性切換を行い正しく通信する。
【０００４】
図１０は、従来の信号伝送装置の例を示すブロック図である。この信号伝送装置では、信号線１，２に、所定の直流電圧を印加する整流ブロック３を接続し、信号線１，２と送受信ブロック４との間には、伝送信号を反転切り換えする信号切換スイッチ５を設けている。また、正側の信号線１の電位が負側の信号線２の電位より低い場合にのみ異極信号を出力する極性判定回路６を設けている。そして、極性判定回路６が異極信号を出力すると、マイクロコンピュータ（以下「マイコン」と略称する）７内の切換制御部８からの切換信号に従って、信号切換スイッチ５が伝送信号を反転切換を行うようになっている。
【０００５】
ここで、上記極性判定回路６は、両信号線１，２の間に接続された一対の発光ダイオードＰＨＤ１，ＰＨＤ２と、各発光ダイオードＰＨＤ１，ＰＨＤ２からの光をそれぞれ受信して受信結果をマイコン７に伝達する一対のフォトトランジスタＰＨＴ１，ＰＨＴ２とより構成されている。第１の発光ダイオードＰＨＤ１は、信号線１の電位が信号線２の電位より高い場合に発光し、逆に第２の発光ダイオードＰＨＤ２は、信号線２の電位が信号線１の電位より高い場合に発光するようになっている。
【０００６】
したがって、送受信ポートＰ，Ｎを通じて信号線１，２に伝送信号が入力された際に、これに基づいて両発光ダイオードＰＨＤ１，ＰＨＤ２のいずれかが発光し、その発光状態を各フォトトランジスタＰＨＴ１，ＰＨＴ２を通じてマイコン７で検出し、その検出結果に基づいて切換制御部８で信号切換スイッチ５のポート切換を行うことで、送受信ブロック４には正しい極性の信号を入出力させていた。
【０００７】
【発明が解決しようとする課題】
従来の信号伝送装置では、極性判定回路６の発光ダイオードＰＨＤ１，ＰＨＤ２及びフォトトランジスタＰＨＴ１，ＰＨＴ２が故障した場合においては、これらの部品ＰＨＤ１，ＰＨＤ，ＰＨＴ１，ＰＨＴ２を交換しない限り、２本の信号線１，２の極性判定を行うことができなかった。
【０００８】
この場合、信号切換スイッチ５の状態は、極性判定回路６内の部品が故障する以前の状態に保持される。したがって、極性判定回路６の故障後に信号線１，２の極性が正逆反対に入れ換えて接続された場合、このことを検知できずに信号切換スイッチ５が過去の状態に保持されたままになるため、正しい極性での信号伝送を行うことができず、リモートコントロール器（以下「リモコン」と略称する）、室内機及び室外機の間の相互の信号伝送が正しく行われないことになる。
【０００９】
そこで、この発明の課題は、極性判定回路の故障時においても送受信ポートの極性認識を正しく行って信号切換スイッチの自動切換を行うことの可能な信号伝送装置を提供することにある。
【００１０】
【課題を解決するための手段】
上記課題を解決すべく、請求項１に記載の発明は、外部の所定の機器との間で信号の伝送を行う信号伝送装置であって、一対の伝送線が接続される第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）と、前記両信号線（Ｌ１，Ｌ２）のいずれか一方の信号線に反転せずに接続されるとともに他方の信号線に反転して信号の送受信を行う送受信手段（１５）と、前記第１の信号線（Ｌ１）及び前記第２の信号線（Ｌ２）の前記送受信手段（１５）に対する反転及び非反転の関係を相互に切換える信号切換スイッチ（１４）と、前記送受信ブロック（１５）の送受信動作の指示を与えるとともに、前記送受信ブロック（１５）で受信した受信信号に基づいて前記信号切換スイッチ（１４）の接続切換を指示する制御部（１１）とを備え、前記受信信号が有振幅のビットを含む場合に、当該受信信号の所定の単位内において前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるように設定され、前記制御部（１１）は、外部から前記伝送線を通じて前記第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）に前記受信信号が与えられたときに、前記信号切換スイッチ（１４）により反転せずに接続されている側の前記一方の信号線へ、有振幅のビットを含み且つ前記受信信号と同一の単位内に前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるよう設定された任意の送信信号を、前記受信信号の各単位の受信に対応するタイミングで与え、反転せずに接続されている側の前記一方の信号線の信号と反転して接続されている前記他方の信号線の信号とを重畳して合成パターンとし、当該合成パターン中のビットのなかに相殺されたビットが有る場合に前記信号切換スイッチ（１４）に前記第１の信号線（Ｌ１）及び前記第２の信号線（Ｌ２）の前記送受信手段（１５）に対する反転及び非反転の関係を相互に変更切換えするよう指示するものである。
【００１１】
請求項２に記載の発明は、前記第１の信号線（Ｌ１）の電位と前記第２の信号線（Ｌ２）の電位の高低を比較して両信号線（Ｌ１，Ｌ２）の極性を検出する極性検出回路（１０）をさらに備え、前記制御部（１１）は、前記極性検出回路（１０）での検出結果に基づいて前記信号切換スイッチ（１４）を切換制御する機能をさらに有するものである。
【００１２】
請求項３に記載の発明は、前記制御部（１１）は、前記極性検出回路（１０）での検出結果に基づいて前記信号切換スイッチ（１４）の極性を判定する極性判定手段（２１）と、前記任意の送信信号を前記送受信ブロック（１５）を通じて反転せずに接続された側の前記一方の信号線に前記送信信号を出力するよう前記送受信ブロック（１５）に指示する信号出力指示手段（２２）と、前記信号出力指示手段（２２）で前記任意の送信信号を出力したときの前記合成パターン中の各ビットの振幅値を検出し、この検出結果に基づいて当該各ビットのなかに相殺されたビットが有るかどうかを検出する振幅レベル検出手段（２３）と、前記極性判定手段（２１）での判定結果に従って前記信号切換スイッチ（１４）を切換制御するとともに、前記振幅レベル検出手段（２３）において上記合成パターン中に相殺されたビットが有る場合に前記信号切換スイッチ（１４）の前記第１の信号線（Ｌ１）及び前記第２の信号線（Ｌ２）に対する反転及び非反転の関係を相互に変更切換えするよう指示を与える切換制御手段２４とを有せしめられたものである。
【００１３】
請求項４に記載の発明は、前記信号伝送装置が、空気調和機の室内機に設けられ、当該空気調和機の操作を遠隔操作する操作部との間の信号伝送に用いられるものである。
【００１４】
請求項５に記載の発明は、前記信号伝送装置が、空気調和機の室内機に設けられ、当該空気調和機の室外機との間の信号伝送に用いられるものである。
【００１５】
請求項６に記載の発明は、前記信号伝送装置が、空気調和機の室外機に設けられ、当該空気調和機の室内機との間の信号伝送に用いられるものである。
【００１６】
請求項７に記載の発明は、所定の単位内において有振幅のビットが存在する場合に当該有振幅のビットを示すパルス波形が正負交互のタイミングで現れるように設定された受信信号が、外部から伝送線を通じて第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）に与えられたときに、前記第１の信号線（Ｌ１）の電位と前記第２の信号線（Ｌ２）の電位の高低を所定の極性検出回路（１０）で比較して両信号線（Ｌ１，Ｌ２）の極性を検出し、検出された極性に応じて信号切換スイッチ（１４）を切換駆動して、前記第１の信号線（Ｌ１）及び前記第２の信号線（Ｌ２）の前記送受信手段（１５）に対する反転及び非反転の関係を相互に変更切換えする第１の工程と、外部から伝送線を通じて第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）に受信信号が与えられたときに、信号切換スイッチ（１４）により反転せずに接続されている側の一方の信号線へ、有振幅のビットを含み且つ前記受信信号と同一の単位内に前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるよう設定された任意の送信信号を、前記受信信号の各単位の受信に対応するタイミングで与える第２の工程と、前記第２の工程と並行して、反転せずに接続されている側の前記一方の信号線の信号と反転して接続されている他方の信号線の信号とを重畳して合成パターンとし、当該合成パターンの各ビットの振幅値を認識する第３の工程と、前記合成パターンの各ビットの振幅値を認識した結果に基づいて、前記合成パターン中のビットのなかに相殺されたビットがあるか否かを検出し、相殺されたビットがなかった場合に、前記信号切換スイッチ（１４）の前記第１の信号線（Ｌ１）及び前記第２の信号線（Ｌ２）の送受信手段（１５）に対する反転及び非反転の関係を維持する一方、前記合成パターン中のビットのなかに相殺されたビットが有る場合に、前記信号切換スイッチ（１４）に前記第１の信号線（Ｌ１）及び前記第２の信号線（Ｌ２）の前記送受信手段（１５）に対する反転及び非反転の関係を相互に変更切換えする第４の工程とを備えるものである。
【００１７】
【作用】
上記課題を解決すべく、請求項１乃至請求項７に記載の発明では、例えば、まず、原則として、受信信号が有振幅のビットを含む場合に、当該受信信号の所定の単位内において前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるようにし、外部から伝送線を通じて第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）に受信信号が与えられたときに、第１の信号線（Ｌ１）の電位と第２の信号線（Ｌ２）の電位の高低を所定の極性検出回路（１０）で比較して両信号線（Ｌ１，Ｌ２）の極性を検出し、検出された極性に応じて信号切換スイッチ（１４）を切換駆動して、第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）の送受信手段（１５）に対する反転及び非反転の関係を相互に変更切換えする。
【００１８】
ただし、極性検出回路（１０）が正常に動作する場合は、異常の動作で極性を十分に判定できるが、極性検出回路（１０）が故障している場合もあり得るため、次いで、外部から伝送線を通じて第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）のいずれかに受信信号が与えられたときに、信号切換スイッチ（１４）により反転せずに接続されている側の一方の信号線へ、有振幅のビットを含み且つ前記受信信号と同一の単位内に前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるよう設定された任意の送信信号を、前記受信信号の各単位の受信に対応するタイミングで非反転で（反転せずに）与える。また、これと並行して、反転せずに接続されている側の一方の信号線の信号と反転接続されている他方の信号線の信号とを重畳して合成パターンとし、当該合成パターンの各ビットの振幅値を認識する。そして、合成パターンの各ビットの振幅値を認識した結果に基づいて、合成パターン中のビットのなかに相殺されたビットがあるかどうかを検出する。相殺されたビットがない場合には、信号切換スイッチ（１４）の第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）の送受信手段（１５）に対する反転及び非反転の関係を維持する。一方、合成パターン中のビットのなかに相殺されたビットが有る場合には、信号切換スイッチ（１４）に第１の信号線（Ｌ１）及び第２の信号線（Ｌ２）の送受信手段（１５）に対する反転及び非反転の関係を相互に変更切換えする。これにより、極性検出回路（１０）が故障しても、支障無く極性判定を行うことができ、これにしたがって信号切換スイッチ（１４）の切換を容易に行うことができる。
【００１９】
かかる発明は、請求項４乃至請求項６のように、空気調和機の室内機、室外機及び遠隔操作のための操作部との間の伝送に有効である。
【００２０】
【発明の実施の形態】
＜信号伝送装置の構成＞
図１はこの発明の一の実施の形態に係る信号伝送装置を示す図である。この信号伝送装置は、例えば空気調和装置の室内機において設置され、送受信ポートＰ，Ｎに２本の図示しない伝送線が接続されて例えばリモコンとの相互間の信号伝送を行う。そして、この信号伝送装置は、外部から送受信ポートＰ，Ｎを通じて信号線Ｌ１，Ｌ２に受信信号が与えられたときにその極性判定を行う極性検出回路１０を設けるとともに、この極性検出回路１０の故障時において補助的に極性判定を行う目的で、極性検出回路１０と別にマイコン１１内に補助極性判定手段１１ａを設けたものである。以下、この信号伝送装置を詳述する。
【００２１】
この信号伝送装置は、平衡通信の信号が与えられる信号線Ｌ１，Ｌ２と送受信ブロック１５との間の接続を反転切り換えする信号切換スイッチ１４が設けられ、この信号切換スイッチ１４の切換は、マイコン１１からの切換信号により切り換えられる。
【００２２】
信号線Ｌ１，Ｌ２を外部と接続するための受信ポートＰ，Ｎは、その形状が対称で、互いに区別が付かない従来のものと同一のものを採用することができる。ここで、第１の信号線Ｌ１は、原則として図３に示された正極の伝送信号Ｐ１のようなパルス波を送受信するための信号線であるのに対し、第２の信号線Ｌ２は原則として図３に示された伝送信号Ｐ２のような接地用の無パルス電圧に維持するための信号線である。
【００２３】
具体的には、伝送信号Ｐ１は、リモコンに対する電源供給のための約１６Ｖの基準電位Ｖａｖを中心として正負約５Ｖの振幅を有する無極性パルス波である。この伝送信号Ｐ１は「０」値と「１」値の二値信号からなり、「０」値のときに基準電位Ｖａｖを基準に約５Ｖの振幅を有し、「１」値のときに基準電位Ｖａｖ（即ち、振幅無し）に維持される。
【００２４】
なお、当該伝送信号Ｐ１は１バイト（８ビット）を１単位として伝送され、この１単位内においては、送受信ブロック１５からの送信信号及び外部からの受信信号ともに、「０」値を示すパルス波形は正負交互に現れることとなる。そして、奇数番目に「０」値が存在する場合のパルスは正方向であり、偶数番目に「０」値が存在する場合のパルスは負方向である。即ち、例えばこの１単位のデータが「０，０，０，０，０，０，０，０」である場合は、図２（Ａ）のように「正，負，正，負，正，負，正，負」といった全てのビットに振幅を有する波形が得られ、また例えば１単位のデータが「１，０，０，１，１，０，０，１」の場合は、図２（Ｂ）のように「振幅無し，負，正，振幅無し，振幅無し，負，正，振幅無し」といった波形が得られ、さらに例えば１単位のデータが「１，１，１，１，１，１，１，１」である場合は、図２（Ｃ）のように全てのビットが振幅を有さない波形が得られる。
【００２５】
これに対し、伝送信号Ｐ２は原則としてグランド電位近傍に維持されており、送受信ブロック１５に入力された後に図３中の符号Ｐ３のように正負が反転されるものである。
【００２６】
ただし、これら両信号線Ｌ１，Ｌ２が、上述及び後述の通り、送受信ポートＰ，Ｎへの外部接続が誤って行われた場合には、両信号Ｐ１，Ｐ２は信号切換スイッチ１４の切換によって、互いに入れ換えられた正逆反対の極性として送受信ブロック１５に伝送されるようになっている。ここで、図３において伝送信号Ｐ１が例えば「０，０，０，０，０，０，０，０…」即ち「正，負，正，負，正，負，正，負…」である場合は、これが反転されて認識されると符号Ｐ４のように「負，正，負，正，負，正，負，正…」となって現れる。一方、伝送信号Ｐ２についてはこれが反転されずに符号Ｐ２のまま維持される。尚、各信号線Ｌ１，Ｌ２にはそれぞれ過電流防止用の抵抗Ｒ１，Ｒ２が接続されている。
【００２７】
信号切換スイッチ１４は、図１では等価回路としてアナログスイッチを示しているが、実際にはトランジスタ等を使用した論理回路内におけるスイッチ素子が使用される。なお、信号切換スイッチ１４と各信号線Ｌ１，Ｌ２との接続においては、図４の如く、信号切換スイッチ１４の送信ＡポートＰａ１と受信ＡポートＰａ２が第１の信号線Ｌ１に接続されるとともに、信号切換スイッチ１４の送信ＢポートＰｂ１と受信ＢポートＰｂ２が第２の信号線Ｌ２に接続されて、合計４ライン接続とされる。
【００２８】
送受信ブロック１５は、信号切換スイッチ１４の送信ＡポートＰａ１及び送信ＢポートＰｂ１のうち、この信号切換スイッチ１４により正極の端子として選択的に切り換えられたいずれか一方が接続される正極の送信Ａ端子Ｑａ１と、負極の端子として選択的に切り換えられた他方が接続される負極の送信Ｂ端子Ｑｂ１と、信号切換スイッチ１４の受信ＡポートＰａ２及び受信ＢポートＰｂ２のそれぞれが送受信ブロック１５に入力される受信Ａ端子Ｑａ２及び受信Ｂ端子Ｑｂ２とが形成されている。
【００２９】
ここで、送受信ブロック１５が負極の送信Ｂ端子Ｑｂ１に出力する信号はグランド電圧を基準として負極性側に反転された信号（反転信号）であり、また正極の送信Ａ端子Ｑａ１に出力する信号は反転されない（非反転信号である）。そして、例えば、図５（Ｂ）及び図７（Ｂ）のような波形で信号線Ｌ１，Ｌ２に送出する送信信号は、常に正極の送信Ａ端子Ｑａ１からいずれかの信号線Ｌ１，Ｌ２に送出される。また、負極の受信Ｂ端子Ｑｂ２から入力された信号は送受信ブロック１５内で反転信号として認識される一方、正極の受信Ａ端子Ｑａ２から入力される信号は非反転信号として送受信ブロック１５内で認識される。そして、受信ブロック１５の内部において、受信ＡポートＱａ２及び受信ＢポートＱｂ２の両入力に係る信号が重畳されて「合成パターン」として認識されるようになっている。
【００３０】
極性検出回路１０は、第１の信号線Ｌ１の電位が第２の信号線Ｌ２の電位より低いか否かを検出するためのものであって、両信号線Ｌ１，Ｌ２の間に接続された一対の発光ダイオードＰＨＤ１，ＰＨＤ２と、当該各発光ダイオードＰＨＤ１，ＰＨＤ２からの光をそれぞれ受信して受信結果をマイコン１１に伝達する一対のフォトトランジスタＰＨＴ１，ＰＨＴ２とから構成されている。そして、第１の発光ダイオードＰＨＤ１は、第１の信号線Ｌ１の電位が第２の信号線Ｌ２の電位より高い場合に発光し、逆に第２の発光ダイオードＰＨＤ２は、第２の信号線Ｌ２の電位が第１の信号線Ｌ１の電位より高い場合に発光するようになっている。
【００３１】
マイコン１１は、極性検出回路１０のフォトトランジスタＰＨＴ１，ＰＨＴ２からの信号により信号線Ｌ１，Ｌ２の極性判定を行う極性判定手段２１と、上記補助極性判定手段１１ａと、極性判定手段２１及び補助極性判定手段１１ａでの各判定結果に基づいて信号切換スイッチ１４の切り換えを行う切換制御手段２４とを有している。
【００３２】
極性判定手段２１は、具体的には、送受信ポートＰ，Ｎを通じて信号線Ｌ１，Ｌ２に伝送信号が入力された際に、これに基づいて駆動される両発光ダイオードＰＨＤ１，ＰＨＤ２の発光状態を各フォトトランジスタＰＨＴ１，ＰＨＴ２を通じて検出し、その検出結果に基づいて信号切換スイッチ１４のポート切換を行うことで、送受信ブロック１５に正しい極性の信号を入出力させるものである。
【００３３】
補助極性判定部１１ａは、外部から信号線Ｌ１，Ｌ２に与えられた受信信号同士を重畳して得られた合成パターンの各ビットが相殺されている場合には受信ポートＰ，Ｎに対して誤った接続がされていると判断する一方、相殺されていない場合は正常に接続されていると判断し、かかる判断結果に基づいて受信ポートＰ，Ｎから送受信ブロック１５への信号の授受を切換えるものであって、外部のリモコンから受信信号が与えられたときにこの受信信号に同期して任意の送信信号を送受信ブロック１５を通じて信号線Ｌ１，Ｌ２に送出する信号出力指示手段２２と、上記受信信号の受信及び送信信号の送出によって送受信ブロック１５で得られた合成パターンの振幅が所定の振幅レベル以上かどうかを検出する振幅レベル検出手段２３とを備える。
【００３４】
信号出力指示手段２２は、外部のリモコンから与えられた受信信号（図５（Ａ）に例示する）に同期して、任意の送信信号（図５（Ｂ）に例示する）を正極の送信Ａ端子Ｑａ１から出力するよう、送受信ブロック１５に指示を与えるものである。ここで、任意の送信信号（図５（Ｂ））の送信は１バイト（８ビット）を１単位として、上記受信信号（図５（Ａ））の各単位（１バイト）の受信とほぼ同じタイミングで行われる。そしてこの送信信号は、信号線Ｌ１，Ｌ２のうち信号切換スイッチ１４によって送受信ブロック１５の正極の送信Ａ端子Ｑａ１に接続された側の信号線に入力されることになる。
【００３５】
振幅レベル検出手段２３は、送受信ブロック１５に入力されて重畳された合成パターンを検出し、その各ビットの振幅値のレベルの大小を認識するもので、具体的には、信号出力指示手段２２から指示した送信信号のうち、「０」値のビットに相当するものとして合成パターン内に現れたビット（以下「判定ビット」と称す）の振幅を検出し、これが一定の振幅値（例えば２．５Ｖ：以下「基準振幅値」と称す）以上であれば、信号切換スイッチ１４の切換状態が送受信ポートＰ，Ｎの接続極性に対して「適合的」であると判断する一方、判定ビットの振幅値が基準振幅値未満であれば、信号切換スイッチ１４の切換状態が送受信ポートＰ，Ｎの接続極性に対して「不適合的」であると判断するものである。
【００３６】
切換制御手段２４は、極性判定手段２１によって判定された極性に応じて信号切換スイッチ１４の切換制御を行う（第１の切換制御機能）とともに、振幅レベル検出手段２３によって「不適合的」と判断された場合にも信号切換スイッチ１４の切換状態を変更するよう切換信号を出力する（第２の切換制御機能）ものである。ここで、第１の切換制御機能と第２の切換制御機能の切換は、一定の遅延時間だけずらして交互に行い、同時には行わないようになっている。そして、極性判定手段２１によって極性切換の必要があると判定されたこと（第１の事象）と、振幅レベル検出手段２３によって「不適合的」と判断されたこと（第２の事象）のいずれかの事象が発生するまでは、それ以前の信号切換スイッチ１４の状態を維持するものとなっている。また、切換制御手段２４において第１の切換制御機能が稼動しているときには、補助極性判定部１１ａの信号出力指示手段２２及び振幅レベル検出手段２３は停止するようになっている。
【００３７】
なお、図１中の符号２５は、信号線Ｌ１，Ｌ２及び送受信ポートＰ，Ｎを通じて外部のリモコンに電源としての１６Ｖの整流電流を供給する整流ブロックである。また、マイコン１１内の各要素２１〜２４は、ＲＯＭおよびＲＡＭ等が内蔵された一般的なＭＰＵ内において所定のソフトウェアプログラムによって動作する機能部品である。
【００３８】
＜極性検出回路１０が正常な場合の動作＞
上記構成の信号伝送装置の正常作動時の動作を説明する。信号伝送装置は、信号線Ｌ１，Ｌ２を通じて外部のリモコンからの受信信号を受信する。この場合、極性検出回路１０及び極性判定手段２１による極性判定と、補助極性判定部１１ａによる補助的極性判定とは、一定の遅延時間だけずらして交互に行われる。
【００３９】
例えば、まず第１の信号線Ｌ１にパルス状の伝送信号Ｐ１（図３）が受信された場合には、第２の信号線Ｌ２には、グランド電位近傍に維持された伝送信号Ｐ２（図３）が受信され、この場合には極性検出回路１０の第１の発光ダイオードＰＨＤ１のみが発光する。そして、極性検出回路１０において、第１のフォトトランジスタＰＨＴ１のみが第１の発光ダイオードＰＨＤ１からの光を検出し、これに基づいて、極性判定手段２１は第１の信号線Ｌ１が正極であると判断し、これに応じて信号切換スイッチ１４の切換制御を行う。
【００４０】
逆に、第２の信号線Ｌ２にパルス状の伝送信号Ｐ１（図３）が受信された場合には、第１の信号線Ｌ１には、グランド電位近傍に維持された伝送信号Ｐ２（図３）が受信され、この場合には極性検出回路１０の第２の発光ダイオードＰＨＤ２のみが発光する。そして、極性検出回路１０において、第２のフォトトランジスタＰＨＴ２のみが第２の発光ダイオードＰＨＤ２からの光を検出し、これに基づいて、マイコン１１内の極性判定手段２１は第２の信号線Ｌ２が正極である旨を判断し、これに応じて信号切換スイッチ１４の切換制御を行う。
【００４１】
このような極性検出回路１０及び極性判定手段２１による極性判定の後、補助極性判定部１１ａによる補助的な極性判定が行われる。ただし、極性検出回路１０の各要素ＰＨＤ１，ＰＨＤ２，ＰＨＴ１，ＰＨＴ２が正常な場合（故障でない場合）、補助極性判定部１１ａによる補助的な極性判定結果は極性検出回路１０及び極性判定手段２１による極性判定結果と一致するため、ここではその詳しい説明を省略する。尚、補助極性判定部１１ａの詳細な動作は後述する。
【００４２】
＜極性検出回路１０が故障した場合の動作＞
次に、極性検出回路１０の各要素ＰＨＤ１，ＰＨＤ２，ＰＨＴ１，ＰＨＴ２が故障をした場合の動作を説明する。尚ここでは、説明の簡便のため、全ての要素ＰＨＤ１，ＰＨＤ２，ＰＨＴ１，ＰＨＴ２が故障した場合について説明するが、一部のみの要素ＰＨＤ１，ＰＨＤ２，ＰＨＴ１，ＰＨＴ２が故障した場合も、補助極性判定部１１ａが同様の動作を行うことはいうまでもない。
【００４３】
この場合も、極性検出回路１０及び極性判定手段２１の判定動作と補助極性判定部１１ａによる判定動作とは交互に繰り返し行われる。ただし、ここでは、極性検出回路１０が故障しており、極性判定手段２１によっては信号線Ｌ１，Ｌ２の正負極性の判定が不可能な状態となっているため、極性判定手段２１での判定結果によって切換制御手段２４が信号切換スイッチ１４の切換制御を行うことはない。したがって、極性判定手段２１での判定タイミングの間は、信号切換スイッチ１４はそれ以前の状態に保持されたままとなる。
【００４４】
次に、補助極性判定部１１ａにより極性判定が行われる。
【００４５】
即ち、まず外部のリモコンから受信信号（図５（Ａ）に例示する）が送受信ポートＰ，Ｎを通じて信号線Ｌ１，Ｌ２に与えられる。この受信信号の受信と同時に、マイコン１１の任意の信号出力指示手段２２は、正極の送信Ａ端子Ｑａ１から任意の送信信号を出力するよう、送受信ブロック１５に指示を与える。
【００４６】
ここで、外部のリモコンとの接続において、正しい送受信ポートＰ，Ｎの外部接続が行われている場合、即ち、正側の送受信ポートＰ側に正極性の伝送路が、負側の送受信ポートＮに負極性の伝送路がそれぞれ接続がされており（以下「正接続状態」と称する）、且つ、信号切換スイッチ１４の切換状態が、「正接続状態」の極性に対して適合的な状態（以下「正切換状態」と称す）である場合には、第１の信号線Ｌ１には、外部のリモコンから送受信ポートＰを通じて与えられた受信信号（図５（Ａ））と、送受信ブロック１５の正極の送信Ａ端子Ｑａ１から信号切換スイッチ１４を通じて与えられた任意の送信信号（図５（Ｂ））とが重畳して認識されることになる。
【００４７】
尚、この受信信号（図５（Ａ））と任意の送信信号（図５（Ｂ））とは、必ずしも同一の波形とはならないが、第１の信号線Ｌ１においては、「０」値を示すパルス波形が必ず正負交互に現れることとなるため、このパルス波形に従って両信号が規則正しく重畳される。即ち、１単位の受信信号のデータが例えば「１，０，０，１，１，０，０，１」である場合は、図５（Ａ）のように「振幅無し，負，正，振幅無し，振幅無し，負，正，振幅無し」といった波形となり、正の振幅が現れるとすれば必ず奇数番目に現れ、負の振幅が現れるとすれば必ず偶数番目に現れる。また１単位の送信信号のデータが例えば「０，１，０，０，１，０，１，０」である場合は、図５（Ｂ）のように「正，振幅無し，正，負，振幅無し，負，振幅無し，負」といった波形となり、正の振幅が現れるとすれば必ず奇数番目に現れ、負の振幅が現れるとすれば必ず偶数番目に現れる。即ち、受信信号と送信信号との各ビットの符号配列は、正の方向と負の方向とで一致しており、これらを重畳したとしても、相殺されることはあり得ない。即ち、信号切換スイッチ１４の切換が極性に対して「適合的」である場合は、送信信号と受信信号とが重畳して合成パターンを形成する際、送受信ブロック１５からの送信信号中の有振幅のビットが相殺されることはない。図６は、この場合の合成パターンを示す図であり、図６中の（０）で示したビットは、図５（Ｂ）において送信信号中に含まれていた有振幅の「０」値のビットに対応している。
【００４８】
かかる第１の信号線Ｌ１中の合成パターンは、信号切換スイッチ１４を通じて送受信ブロック１５の受信Ａ端子Ｑａ２に入力される。尚、この場合、受信Ｂ端子Ｑｂ２には第２の信号線Ｌ２の電圧レベルが反転して入力されるが、第２の信号線Ｌ２においては、ほぼグランド電圧に等しい電圧として外部のリモコンから与えられた定電圧の状態が維持されており、図６に示した合成パターンに与える影響はほとんどない。
【００４９】
この図６のように、信号出力指示手段２２の指示により送受信ブロック１５から送出された送信信号において「０」値のビットに対応する合成パターン中のビットは、全て有振幅のビットとなって現れる。したがって、振幅レベル検出手段２３により、これらの合成パターン中のビットの振幅値を一定の基準振幅値Ｔｈと比較して、送信信号の「０」値に対応する全てのビット（図６中の（０）印）の振幅値が基準振幅値Ｔｈより大であることを確認できれば（図６中の◎印）、信号切換スイッチ１４の切換状態は信号線Ｌ１，Ｌ２の極性に対して「適合的」であると判断でき、故に信号切換スイッチ１４の切換状態はそのまま保持される。
【００５０】
次に、送受信ポートＰ，Ｎの外部接続が「正接続状態」であるにも拘わらず、信号切換スイッチ１４の切換状態が、「逆接続状態」の極性に対して適合的な状態（以下「逆切換状態」と称す）である場合を説明する。尚、この場合において外部のリモコンから受信される受信信号は図５（Ａ）に示したものであり、また送受信ブロック１５から送出される送信信号は図５（Ｂ）に示したものとする。
【００５１】
この場合には、第１の信号線Ｌ１には、図５（Ａ）に示した受信信号が受信され、第２の信号線Ｌ２には、ほぼグランド電圧に等しい電圧として外部のリモコンから与えられた定電圧の状態（図３中の符号Ｐ２）と、送受信ブロック１５からの送信信号が重畳されて現れる。
【００５２】
そして、信号切換スイッチ１４を通じて送受信ブロック１５の受信Ａ端子Ｑａ２及び受信Ｂ端子Ｑｂ２に入力される際には、第２の信号線Ｌ２の波形は非反転信号として図５（Ｂ）の波形がそのまま入力されて図７（Ｂ）のようになる。一方、第１の信号線Ｌ１の波形は反転されて図７（Ａ）のようになる。そして送受信ブロック１５の内部において、両者は互いに重畳されて図８のような合成パターンとなる。図８中の（０）で示したビットは、図５（Ｂ）において送信信号中に含まれていた有振幅の「０」値のビットに対応している。
【００５３】
ここで、図７（Ａ）においては、「１，０，０，１，１，０，０，１」の符号系列データである受信信号は、「振幅無し，正，負，振幅無し，振幅無し，正，負，振幅無し」といった波形となり、正の振幅が現れるとすれば必ず偶数番目に現れ、負の振幅が現れるとすれば必ず奇数番目に現れる。これは、図５（Ａ）の場合と正負が逆になっている。また「０，１，０，０，１，０，１，０」の符号系列データである送信信号（図７（Ｂ））は、図５（Ｂ）の場合と同様に「正，振幅無し，正，負，振幅無し，負，振幅無し，負」といった波形となり、正の振幅が現れるとすれば必ず奇数番目に現れ、負の振幅が現れるとすれば必ず偶数番目に現れる。即ち、受信信号と送信信号との各ビットの符号配列は、正の方向と負の方向とで逆向きになっており、これらを重畳したとすれば、たまたま送信信号と受信信号の両方が「０」値をとったときに、そのタイミングで当該ビットが相殺されることになる。即ち、信号切換スイッチ１４の切換が極性に対して「適合的でない」場合は、送信信号と受信信号とを重畳して合成パターンを形成する際、図８中の×印（相殺ビット）のように、送受信ブロック１５からの送信信号中のいくつかの有振幅のビットが相殺される。
【００５４】
また、外部のリモコンとの接続において、正接続状態とは反対に送受信ポートＰ，Ｎの外部接続がなされている状態（以下「逆接続状態」という：即ち、この場合は正側の送受信ポートＰ側に負極性の伝送路が、負側の送受信ポートＮに正極性の伝送路がそれ接続された状態）にも拘わらず、信号切換スイッチ１４の切換状態が「正切換状態」（即ち、信号切換スイッチ１４の切換状態が、逆接続状態に対して非適合的である状態）である場合には、第１の信号線Ｌ１には、ほぼグランド電圧に等しい電圧として外部のリモコンから与えられた定電圧の状態と、送受信ブロック１５の正極の送信Ａ端子Ｑａ１から信号切換スイッチ１４を通じて与えられた任意の送信信号とが重畳して、図７（Ｂ）のような波形の信号が現れる。また、第２の信号線Ｌ２においては、外部のリモコンから与えられた図５（Ａ）と同様な受信信号がそのまま現れる。そして、各信号線Ｌ１，Ｌ２の信号が信号切換スイッチ１４を通じて送受信ブロック１５の受信Ａ端子Ｑａ２及び受信Ｂ端子Ｑｂ２にそれぞれ入力される際には、第１の信号線Ｌ１の波形は非反転信号として図７（Ａ）の波形のまま維持されるが、第２の信号線Ｌ２の波形は反転されて図７（Ｂ）のようになり、両者は送受信ブロック１５の内部で互いに重畳された合成パターンとして認識される。このとき、第１の信号線Ｌ１から非反転で入力された図７（Ａ）の波形と、第２の信号線Ｌ２から反転されて入力された図７（Ｂ）の波形の各ビットの符号配列は、正の方向と負の方向とで逆向きになっており、これらを重畳したとすれば、いくつかのビットが相殺されることになる。即ち、信号切換スイッチ１４の切換が極性に対して「適合的でない」場合は、送信信号と受信信号とを重畳して合成パターンを形成する際、図８中の×印のように、送受信ブロック１５からの送信信号中のいくつかの有振幅のビットが相殺される。
【００５５】
さらに、送受信ポートＰ，Ｎの外部接続が「逆接続状態」であり、且つ、信号切換スイッチ１４の切換状態が「逆切換状態」である場合には、第１の信号線Ｌ１は、ほぼグランド電圧に等しい電圧として外部のリモコンから与えられた定電圧の状態となる。また、第２の信号線Ｌ２には、外部のリモコンから送受信ポートＰを通じて与えられた受信信号（図５（Ａ））と、送受信ブロック１５の正極の送信Ａ端子Ｑａ１から信号切換スイッチ１４を通じて与えられた任意の送信信号（図５（Ｂ））とが重畳して入力されることになる。かかる第２の信号線Ｌ２中の合成パターンは、図６のように、振幅の大きな波形となって現れ、信号切換スイッチ１４を通じて非反転入力信号として送受信ブロック１５の受信Ａ端子Ｑａ２に入力される。また、受信Ｂ端子Ｑｂ２には、併せて第１の信号線Ｌ１の電圧レベルも反転して入力される。第１の信号線Ｌ１においては、ほぼグランド電圧に等しい電圧となる。
【００５６】
これらの対応関係を図９に示す。図９の如く、送受信ポートＰ，Ｎが正接続状態とされ且つ信号切換スイッチ１４が正切換状態のときと、送受信ポートＰ，Ｎが逆接続状態とされ且つ信号切換スイッチ１４が逆切換状態のとき、即ち信号切換スイッチ１４の切換状態が送受信ポートＰ，Ｎの接続状態に適合的な状態である場合には、合成パターン内に相殺ビットがないことになる。これに対して、送受信ポートＰ，Ｎが正接続状態とされているにも拘わらず信号切換スイッチ１４が逆切換状態のときと、送受信ポートＰ，Ｎが逆接続状態とされているにも拘わらず信号切換スイッチ１４が正切換状態のとき、即ち信号切換スイッチ１４の切換状態が送受信ポートＰ，Ｎの接続状態に非適合的な状態である場合には、合成パターン内に相殺ビットが有ることになる。
【００５７】
したがって、振幅レベル検出手段２３において、送信信号中の有振幅の「０」値のビットに対応する合成パターンのビットのなかに、１個でも相殺ビット（図８中の×印）があれば、信号切換スイッチ１４の信号線Ｌ１，Ｌ２に対する極性対応関係が逆であることを判断できたことになり、切換制御手段２４により信号切換スイッチ１４を現状から逆側ら切り換える。以後、この信号伝送装置を通じて室内機とリモコンとの間で伝送信号の伝送を行って、所定の制御動作を行えばよい。
【００５８】
尚、上記した補助極性判定部１１ａの動作において、送信信号が「０」値を含んでいない場合は、合成パターンが相殺されたかどうかを検出することができないが、送信信号が永久に「１」値しか送信しないといった事態はあり得ず、ほぼ一定の頻度で「０」値を出力するため、この任意のパターンの送信信号中にたまたま出現した「０」値について、これが合成パターンにおいて相殺されるかどうかを判定しつづけ、外部からの受信信号中の「０」値とたまたま同期したときに、切換制御手段２４を通じて信号切換スイッチ１４の切換を行うようにすればよい。
【００５９】
以上のように、この実施の形態に係る信号伝送装置では、極性検出回路１０がとは別に、外部からの受信信号と送受信ブロック１５から送出した任意の送信信号とを照合して、合成パターンのうち相殺ビットがあるかどうかを検出するだけで、送受信ポートＰ，Ｎの接続状態に対する信号切換スイッチ１４の切換状態が適合的か否かを容易に判断できるので、極性検出回路１０が故障したときでも、容易に信号切換スイッチ１４の適合性を判断して自動的に切換制御を行うことができる。
【００６０】
尚、上記実施の形態においては、室内機内に設置されてリモコンとの伝送信号の送受信を行うためのものとして信号伝送装置を説明したが、その他、室内機内に設置されて室外機との伝送信号の送受信を行うためのものや、あるいは、室外機内に設置されて室内機との伝送信号の送受信を行うためのもの等に適用してもよい。特に、複数の室内機が単一または複数の室外機に所定のネットワークを通じて接続される場合においてこれらの室外機と室内機との間の信号伝送に適用するのが有効である。
【００６１】
【発明の効果】
請求項１乃至請求項７に記載の発明によれば、まず、原則として、受信信号が有振幅のビットを含む場合に、当該受信信号の所定の単位内において前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるようにし、外部から伝送線を通じて第１の信号線及び第２の信号線に受信信号が与えられたときに、第１の信号線の電位と第２の信号線の電位の高低を所定の極性検出回路で比較して両信号線の極性を検出し、検出された極性に応じて信号切換スイッチを切換駆動して、第１の信号線及び第２の信号線の送受信手段に対する反転及び非反転の関係を相互に変更切換えするとともに、次いで、外部から伝送線を通じて第１の信号線及び第２の信号線のいずれかに所定の受信信号が与えられたときに、信号切換スイッチにより反転せずに接続されている側の一方の信号線へ、有振幅のビットを含み且つ前記受信信号と同一の単位内に前記有振幅のビットを示すパルス波形が正負交互のタイミングで現れるよう設定された任意の送信信号を、前記受信信号の各単位の受信に対応するタイミングで与え、また、これと並行して、反転せずに接続されている側の一方の信号線の信号と反転して接続されている他方の信号線の信号とを重畳して合成パターンとし、当該合成パターンの各ビットの振幅値を認識し、合成パターンの各ビットの振幅値を認識した結果に基づいて、合成パターン中のビットのなかに相殺されたビットがあるかどうかを検出して、相殺されたビットがない場合に、信号切換スイッチの第１の信号線及び第２の信号線の送受信手段に対する反転及び非反転の関係を維持する一方、合成パターン中のビットのなかに相殺されたビットが有る場合には、信号切換スイッチに第１の信号線及び第２の信号線の送受信手段に対する反転及び非反転の関係を相互に変更切換えするようになっているので、極性検出回路が故障しても、支障無く極性判定を行うことができ、この判定結果にしたがって信号切換スイッチの切換を容易に行うことができるという効果がある。
【００６２】
かかる発明は、請求項４乃至請求項６のように、空気調和機の室内機、室外機及び遠隔操作のための操作部との間の伝送に有効である。
【図面の簡単な説明】
【図１】この発明の一の実施の形態に係る信号伝送装置を示すブロック図である。
【図２】この発明の一の実施の形態における信号波形を示す図である。
【図３】この発明の一の実施の形態における信号波形を示す図である。
【図４】この発明の一の実施の形態における接続関係を示すブロック図である。
【図５】この発明の一の実施の形態における送受信ブロックの受信端子に与えられる信号の合成前の状態を示す波形図である。
【図６】この発明の一の実施の形態における送受信ブロックの受信端子に与えられる信号の合成後の状態を示す波形図である。
【図７】この発明の一の実施の形態における送受信ブロックの受信端子に与えられる信号の合成前の状態を示す波形図である。
【図８】この発明の一の実施の形態における送受信ブロックの受信端子に与えられる信号の合成後の状態を示す波形図である。
【図９】この発明の一の実施の形態の動作を示す図である。
【図１０】従来の信号伝送装置を示すブロック図である。
【符号の説明】
１０極性判定回路、１１マイコン、１４信号切換スイッチ、１５送受信ブロック、２１極性判定手段、２２信号出力指示手段、２３振幅レベル検出手段、２４切換制御手段、Ｐ，Ｎ送受信ポート、Ｌ１第１の信号線、Ｌ２第２の信号線、ＰＨＤ１，ＰＨＤ２発光ダイオード、ＰＨＴ１，ＰＨＴ２フォトトランジスタ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a signal transmission device that performs signal transmission between at least two or more control units, and particularly to a signal transmission device that performs signal depolarization.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, in an air conditioner, a balanced communication system using two signal lines is adopted as a signal transmission system between an indoor unit and an outdoor unit in a remote controller (hereinafter, abbreviated as “remote controller”). (For example, JP-A-5-227568).
[0003]
In this air conditioner, polarities opposite to each other are assigned to each of the two signal lines. Since the polarity is often reversed in the opposite direction due to an erroneous connection or the like at the time of plug connection, such a connection in the opposite direction is allowed, and the polarity of the polarity is reduced in the signal transmission device on the receiving side during communication. Judgment is performed, the polarity of the transmission / reception port is automatically switched, and correct communication is performed.
[0004]
FIG. 10 is a block diagram illustrating an example of a conventional signal transmission device. In this signal transmission device, a rectifier block 3 for applying a predetermined DC voltage is connected to the signal lines 1 and 2, and a signal switch for inverting and switching a transmission signal is provided between the signal lines 1 and 2 and the transmission / reception block 4. A switch 5 is provided. Further, a polarity determination circuit 6 that outputs a different polarity signal only when the potential of the positive signal line 1 is lower than the potential of the negative signal line 2 is provided. When the polarity judging circuit 6 outputs a different polarity signal, the signal changeover switch 5 inverts the transmission signal in accordance with a changeover signal from a changeover control unit 8 in a microcomputer 7. It has become.
[0005]
Here, the polarity determination circuit 6 receives a pair of light-emitting diodes PHD1 and PHD2 connected between the two signal lines 1 and 2 and light from each of the light-emitting diodes PHD1 and PHD2, and receives the reception result as a microcomputer 7 , And a pair of phototransistors PHT1 and PHT2 for transmitting the signals. The first light emitting diode PHD1 emits light when the potential of the signal line 1 is higher than the potential of the signal line 2, and conversely, the second light emitting diode PHD2 emits light when the potential of the signal line 2 is higher than the potential of the signal line 1. It is designed to emit light.
[0006]
Therefore, when a transmission signal is input to the signal lines 1 and 2 through the transmission / reception ports P and N, one of the two light emitting diodes PHD1 and PHD2 emits light based on the signal, and the light emission state is changed to the phototransistors PHT1 and PHT2. Through the microcomputer 7, and the switching control unit 8 switches the port of the signal changeover switch 5 based on the detection result.
[0007]
[Problems to be solved by the invention]
In the conventional signal transmission device, when the light emitting diodes PHD1 and PHD2 of the polarity determination circuit 6 and the phototransistors PHT1 and PHT2 fail, two signal lines are used unless these components PHD1, PHD, PHT1 and PHT2 are replaced. Polarity determination of 1 and 2 could not be performed.
[0008]
In this case, the state of the signal changeover switch 5 is maintained at the state before the components in the polarity determination circuit 6 fail. Therefore, if the polarity of the signal lines 1 and 2 is reversed and connected after the failure of the polarity judgment circuit 6, this cannot be detected and the signal changeover switch 5 is kept in the past state. Therefore, signal transmission with correct polarity cannot be performed, and mutual signal transmission between the remote controller (hereinafter, abbreviated as “remote controller”), the indoor unit, and the outdoor unit is not performed correctly.
[0009]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a signal transmission device capable of correctly recognizing the polarity of a transmission / reception port and automatically switching a signal changeover switch even when a polarity determination circuit fails.
[0010]
[Means for Solving the Problems]
In order to solve the above problem, an invention according to claim 1 is a signal transmission device for transmitting a signal to and from a predetermined external device, wherein a first signal line to which a pair of transmission lines is connected is provided. (L1) and the second signal line (L2) are connected to one of the two signal lines (L1, L2) without being inverted, and are inverted to the other signal line to transmit and receive signals. And a signal changeover switch () for mutually switching the inverting and non-inverting relationship of the first signal line (L1) and the second signal line (L2) with respect to the transmitting / receiving means (15). 14) and giving an instruction of the transmitting / receiving operation of the transmitting / receiving block (15) ,Previous A control unit (11) for instructing connection switching of the signal changeover switch (14) based on a reception signal received by the transmission / reception block (15); When the received signal includes a bit of amplitude, the pulse waveform indicating the bit of the amplitude within a predetermined unit of the received signal is set to appear at alternating positive and negative timing, The control unit (11) externally connects the first signal line (L1) and the second signal line (L2) through the transmission line. Said When a received signal is applied, the signal is switched to the one signal line on the side connected without being inverted by the signal changeover switch (14). , The pulse waveform including the bit with the amplitude and indicating the bit with the amplitude in the same unit as the received signal is set so as to appear at the alternating timing of positive and negative. Any transmitted signal At the timing corresponding to the reception of each unit of the received signal. The signal of the one signal line on the side connected without inversion is superimposed on the signal of the other signal line connected and inverted to form a composite pattern, and the bits of the bit in the composite pattern are superimposed. When there is a canceled bit, the signal changeover switch (14) switches the first signal line (L1) and the second signal line (L2) between inverted and non-inverted with respect to the transmitting / receiving means (15). It instructs that the relationships be changed and switched to each other.
[0011]
According to a second aspect of the present invention, the polarity of both signal lines (L1, L2) is detected by comparing the level of the potential of the first signal line (L1) with the level of the potential of the second signal line (L2). The control section (11) further has a function of controlling switching of the signal changeover switch (14) based on a detection result of the polarity detection circuit (10). is there.
[0012]
According to a third aspect of the present invention, the control unit (11) includes a polarity determination unit (21) that determines a polarity of the signal changeover switch (14) based on a detection result of the polarity detection circuit (10). Signal output instructing means for instructing the transmission / reception block (15) to output the transmission signal to the one signal line on the side connected without inverting the arbitrary transmission signal through the transmission / reception block (15) ( 22) and the signal output instructing means (22) detects the amplitude value of each bit in the composite pattern when the arbitrary transmission signal is output, and cancels out each of the bits based on the detection result. An amplitude level detecting means (23) for detecting whether or not there is a selected bit, and switching control of the signal changeover switch (14) in accordance with the result of judgment by the polarity judging means (21). When the amplitude level detecting means (23) has a canceled bit in the composite pattern, the signal changeover switch (14) inverts the first signal line (L1) and the second signal line (L2). And a switching control means 24 for giving an instruction to change and switch the non-inverting relationship to each other.
[0013]
According to a fourth aspect of the present invention, the signal transmission device is provided in an indoor unit of an air conditioner, and is used for signal transmission with an operation unit that remotely operates the air conditioner.
[0014]
According to a fifth aspect of the present invention, the signal transmission device is provided in an indoor unit of an air conditioner and is used for signal transmission with an outdoor unit of the air conditioner.
[0015]
According to a sixth aspect of the present invention, the signal transmission device is provided in an outdoor unit of an air conditioner, and is used for signal transmission with the indoor unit of the air conditioner.
[0016]
The invention according to claim 7 is When there is a bit of amplitude within a predetermined unit, a reception signal set so that a pulse waveform indicating the bit of amplitude has a positive / negative alternating timing, A first signal line (L1) and a second signal line (L2) through a transmission line from outside To When it is obtained, the potential of the first signal line (L1) and the potential of the second signal line (L2) are compared by a predetermined polarity detection circuit (10), and both signal lines (L1, L2) are compared. L2), and switches the signal changeover switch (14) in accordance with the detected polarity to drive the signal transmission / reception means of the first signal line (L1) and the second signal line (L2). (15) a first step of mutually changing and inverting the inversion and non-inversion relations, and a reception signal being externally supplied to the first signal line (L1) and the second signal line (L2) via a transmission line. One of the signal lines on the side connected without being inverted by the signal changeover switch (14) To, a pulse waveform including bits with amplitude and indicating the bits with amplitude in the same unit as the received signal was set to appear at alternating positive and negative timings Any transmitted signal At the timing corresponding to the reception of each unit of the received signal. A second step of providing, and in parallel with the second step, a signal of the one signal line on the side connected without inversion and a signal of the other signal line connected in reverse. A third step of superimposing a combined pattern and recognizing an amplitude value of each bit of the combined pattern; and a step of recognizing an amplitude value of each bit of the combined pattern based on a result of recognizing an amplitude value of each bit of the combined pattern. It is detected whether or not there is a canceled bit. If there is no canceled bit, the first signal line (L1) and the second signal line (L2) of the signal changeover switch (14) are detected. ) While maintaining the inverting and non-inverting relationship with respect to the transmitting / receiving means (15), if there is a canceled bit among the bits in the composite pattern, the signal changeover switch (14) applies the first signal to the signal changeover switch (14). Line (L1) and the In which and a fourth step of changing switched mutually inverting and non-inverting relationship to the receiving means of the signal line (L2) (15).
[0017]
[Action]
In order to solve the above problems, in the inventions according to claims 1 to 7, for example, first, in principle, When the received signal includes a bit of amplitude, in a predetermined unit of the received signal, so that a pulse waveform indicating the bit of the amplitude appears at alternating positive and negative timing, When a reception signal is given to the first signal line (L1) and the second signal line (L2) from outside via a transmission line, the potential of the first signal line (L1) and the second signal line (L2) ) Is compared by a predetermined polarity detection circuit (10) to detect the polarity of both signal lines (L1, L2), and switches and drives the signal changeover switch (14) according to the detected polarity. , The first signal line (L1) and the second signal line (L2) inverting and non-inverting with respect to the transmitting / receiving means (15) are mutually changed and switched.
[0018]
However, when the polarity detection circuit (10) operates normally, the polarity can be sufficiently determined by the abnormal operation. However, the polarity detection circuit (10) may be out of order. One of the first signal line (L1) and the second signal line (L2) through the line Received When a signal is supplied, the signal is switched to one signal line on the side connected without being inverted by the signal changeover switch (14). , The pulse waveform including the bit with the amplitude and indicating the bit with the amplitude in the same unit as the received signal is set so as to appear at the alternating timing of positive and negative. Any transmission signal At the timing corresponding to the reception of each unit of the received signal. Give non-inverted (without inversion). In parallel with this, the signal of one signal line on the side connected without inversion and the signal of the other signal line connected in reverse are superimposed to form a composite pattern, and each of the composite patterns is Recognize the bit amplitude value. Then, based on the result of recognizing the amplitude value of each bit of the composite pattern, it is detected whether or not any of the bits in the composite pattern has a canceled bit. When there is no canceled bit, the first and second signal lines (L1) and (L2) of the signal changeover switch (14) maintain the inverting and non-inverting relationship with respect to the transmitting / receiving means (15). . On the other hand, when there is a canceled bit among the bits in the combined pattern, the signal changeover switch (14) transmits / receives the first signal line (L1) and the second signal line (L2) to / from the transmitting / receiving means (15). And inverting and non-inverting relations with respect to. Thus, even if the polarity detection circuit (10) fails, the polarity can be determined without any trouble, and the signal changeover switch (14) can be easily switched accordingly.
[0019]
This invention is effective for transmission between an indoor unit, an outdoor unit and an operation unit for remote control of the air conditioner as described in claims 4 to 6.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
<Configuration of signal transmission device>
FIG. 1 is a diagram showing a signal transmission device according to one embodiment of the present invention. This signal transmission device is installed in, for example, an indoor unit of an air conditioner, and two transmission lines (not shown) are connected to transmission / reception ports P and N to perform signal transmission with, for example, a remote controller. The signal transmission device includes a polarity detection circuit 10 that determines the polarity of a received signal from the outside via the transmission / reception ports P and N to the signal lines L1 and L2 when the signal is received. An auxiliary polarity determination means 11a is provided in the microcomputer 11 separately from the polarity detection circuit 10 for the purpose of performing the polarity determination in some cases. Hereinafter, this signal transmission device will be described in detail.
[0021]
This signal transmission device is provided with a signal changeover switch 14 for inverting and switching the connection between the signal lines L1 and L2 to which balanced communication signals are supplied and the transmission / reception block 15. The signal changeover switch 14 is switched by the microcomputer 11 Is switched by the switching signal from.
[0022]
The reception ports P and N for connecting the signal lines L1 and L2 to the outside can be the same as those of the related art which are symmetric in shape and indistinguishable from each other. Here, the first signal line L1 is, in principle, a signal line for transmitting and receiving a pulse wave such as the positive transmission signal P1 shown in FIG. 3, whereas the second signal line L2 is in principle, A signal line for maintaining a non-pulse voltage for grounding, such as the transmission signal P2 shown in FIG.
[0023]
Specifically, the transmission signal P1 is a non-polar pulse wave having an amplitude of about 5 V in positive and negative directions around a reference potential Vav of about 16 V for power supply to the remote controller. The transmission signal P1 is composed of a binary signal having a value of “0” and a value of “1”. The transmission signal P1 has an amplitude of about 5 V with respect to the reference potential Vav when the value is “0”, and has a reference value when the value is “1”. The potential is maintained at Vav (that is, no amplitude).
[0024]
The transmission signal P1 is transmitted with one byte (8 bits) as one unit. In this one unit, both the transmission signal from the transmission / reception block 15 and the reception signal from the outside have a pulse waveform indicating a “0” value. Will appear alternately. When the odd-numbered “0” value is present, the pulse is in the positive direction, and when the even-numbered “0” value is present, the pulse is in the negative direction. That is, for example, when this one unit of data is “0,0,0,0,0,0,0,0”, as shown in FIG. 2A, “positive, negative, positive, negative, positive, A waveform having amplitudes in all bits such as “negative, positive, negative” is obtained. For example, when one unit of data is “1, 0, 0, 1, 1, 0, 0, 1”, FIG. As shown in B), a waveform such as “no amplitude, negative, positive, no amplitude, no amplitude, negative, positive, no amplitude” is obtained. Further, for example, one unit of data is “1,1,1,1,1,1, In the case of "1, 1, 1", a waveform in which all bits have no amplitude is obtained as shown in FIG.
[0025]
On the other hand, the transmission signal P2 is, in principle, maintained near the ground potential, and after being input to the transmission / reception block 15, the sign is inverted as indicated by the symbol P3 in FIG.
[0026]
However, when the signal lines L1 and L2 are externally connected to the transmission / reception ports P and N by mistake as described above and below, the signals P1 and P2 are switched by the signal changeover switch 14. The data is transmitted to the transmission / reception block 15 with the opposite polarities reversed. Here, in FIG. 3, the transmission signal P1 is, for example, "0, 0, 0, 0, 0, 0, 0, 0 ...", that is, "positive, negative, positive, negative, positive, negative, positive, negative ...". In this case, when this is inverted and recognized, it appears as “negative, positive, negative, positive, negative, positive, negative, positive...” As indicated by the symbol P4. On the other hand, the transmission signal P2 is maintained at P2 without being inverted. Note that resistors R1 and R2 for preventing overcurrent are connected to the signal lines L1 and L2, respectively.
[0027]
Although the signal changeover switch 14 is an analog switch as an equivalent circuit in FIG. 1, a switch element in a logic circuit using a transistor or the like is actually used. In connection between the signal changeover switch 14 and each of the signal lines L1 and L2, as shown in FIG. 4, the transmission A port Pa1 and the reception A port Pa2 of the signal changeover switch 14 are connected to the first signal line L1. The transmission B port Pb1 and the reception B port Pb2 of the signal changeover switch 14 are connected to the second signal line L2, so that a total of four lines are connected.
[0028]
The transmission / reception block 15 is a positive transmission A terminal to which one of the transmission A port Pa1 and the transmission B port Pb1 of the signal changeover switch 14, which is selectively switched as a positive terminal by the signal changeover switch 14, is connected. Qa1, the negative transmission B terminal Qb1 to which the other terminal selectively switched as the negative terminal is connected, and the reception A port Pa2 and the reception B port Pb2 of the signal changeover switch 14 are input to the transmission / reception block 15. A reception A terminal Qa2 and a reception B terminal Qb2 are formed.
[0029]
Here, the signal output from the transmission / reception block 15 to the negative transmission B terminal Qb1 is a signal (inversion signal) inverted to the negative polarity side with reference to the ground voltage, and the signal output to the positive transmission A terminal Qa1 is Not inverted (non-inverted signal). For example, a transmission signal transmitted to the signal lines L1 and L2 with a waveform as shown in FIGS. 5B and 7B is always transmitted from the positive transmission A terminal Qa1 to one of the signal lines L1 and L2. Is done. The signal input from the negative receiving B terminal Qb2 is recognized as an inverted signal in the transmitting / receiving block 15, while the signal input from the positive receiving A terminal Qa2 is recognized as a non-inverted signal in the transmitting / receiving block 15. You. Then, inside the reception block 15, signals related to both inputs of the reception A port Qa2 and the reception B port Qb2 are superimposed and recognized as a "combined pattern".
[0030]
The polarity detection circuit 10 is for detecting whether or not the potential of the first signal line L1 is lower than the potential of the second signal line L2, and is connected between both signal lines L1 and L2. It comprises a pair of light emitting diodes PHD1 and PHD2, and a pair of phototransistors PHT1 and PHT2 for receiving light from the respective light emitting diodes PHD1 and PHD2 and transmitting the reception result to the microcomputer 11. The first light emitting diode PHD1 emits light when the potential of the first signal line L1 is higher than the potential of the second signal line L2. Conversely, the second light emitting diode PHD2 emits light when the potential of the second signal line L2 is higher. Is emitted when the potential of the first signal line L1 is higher than the potential of the first signal line L1.
[0031]
The microcomputer 11 includes a polarity determination unit 21 that determines the polarity of the signal lines L1 and L2 based on signals from the phototransistors PHT1 and PHT2 of the polarity detection circuit 10, the auxiliary polarity determination unit 11a, the polarity determination unit 21, and the auxiliary polarity determination. Switching control means 24 for switching the signal changeover switch 14 based on each determination result in the means 11a.
[0032]
Specifically, when a transmission signal is input to the signal lines L1 and L2 through the transmission and reception ports P and N, the polarity determination unit 21 determines the light emission state of the two light emitting diodes PHD1 and PHD2 driven based on the transmission signal. The signal is detected through the phototransistors PHT1 and PHT2, and the port of the signal changeover switch 14 is switched based on the detection result, so that a signal of the correct polarity is input to and output from the transmission / reception block 15.
[0033]
If the bits of the combined pattern obtained by superimposing the received signals externally applied to the signal lines L1 and L2 are offset, the auxiliary polarity determination unit 11a incorrectly outputs the signals to the reception ports P and N. The connection is determined to be established, while the connection is not canceled, the connection is determined to be normal, and the transmission / reception of signals from the reception ports P and N to the transmission / reception block 15 is switched based on the determination result. A signal output instructing means 22 for transmitting an arbitrary transmission signal to the signal lines L1 and L2 through the transmission / reception block 15 in synchronization with the reception signal when a reception signal is given from an external remote controller; Amplitude level detecting means 23 for detecting whether or not the amplitude of the composite pattern obtained by the transmission / reception block 15 by the reception and transmission of the transmission signal is greater than or equal to a predetermined amplitude level. That.
[0034]
The signal output instructing means 22 synchronizes an arbitrary transmission signal (exemplified in FIG. 5B) with a positive transmission signal A in synchronization with a reception signal (exemplified in FIG. 5A) given from an external remote controller. An instruction is given to the transmission / reception block 15 so as to output from the terminal Qa1. Here, the transmission of an arbitrary transmission signal (FIG. 5 (B)) is substantially the same as the reception of each unit (1 byte) of the reception signal (FIG. 5 (A)), with one byte (8 bits) as one unit. It is done at the timing. This transmission signal is input to the signal line on the side of the signal lines L1 and L2 connected to the positive transmission A terminal Qa1 of the transmission / reception block 15 by the signal changeover switch 14.
[0035]
The amplitude level detection means 23 detects the superimposed composite pattern input to the transmission / reception block 15 and superimposed, and recognizes the magnitude of the amplitude value level of each bit. Among the designated transmission signals, the amplitude of a bit (hereinafter referred to as a “judgment bit”) that appears in the combined pattern as a bit corresponding to a bit of “0” value is detected, and this is detected as a constant amplitude value (for example, 2.5 V). : Hereinafter referred to as "reference amplitude value"), it is determined that the switching state of the signal changeover switch 14 is "adaptive" to the connection polarity of the transmission / reception ports P and N, while the amplitude value of the determination bit Is smaller than the reference amplitude value, it is determined that the switching state of the signal changeover switch 14 is "incompatible" with respect to the connection polarity of the transmission / reception ports P and N.
[0036]
The switching control means 24 controls the switching of the signal changeover switch 14 in accordance with the polarity determined by the polarity determining means 21 (first switching control function), and is determined as “incompatible” by the amplitude level detecting means 23. In this case, a switching signal is output to change the switching state of the signal changeover switch 14 (second switching control function). Here, the switching between the first switching control function and the second switching control function is alternately performed by being shifted by a fixed delay time, and is not performed simultaneously. Either the polarity determination unit 21 determines that the polarity switching is necessary (first event) or the amplitude level detection unit 23 determines that it is “incompatible” (second event). Until the event described above occurs, the previous state of the signal changeover switch 14 is maintained. When the first switching control function is operating in the switching control unit 24, the signal output instruction unit 22 and the amplitude level detection unit 23 of the auxiliary polarity determination unit 11a are stopped.
[0037]
Reference numeral 25 in FIG. 1 denotes a rectification block that supplies a 16 V rectified current as a power source to an external remote controller through the signal lines L1 and L2 and the transmission and reception ports P and N. Each of the elements 21 to 24 in the microcomputer 11 is a functional component operated by a predetermined software program in a general MPU having a ROM, a RAM, and the like.
[0038]
<Operation When Polarity Detection Circuit 10 is Normal>
The operation of the signal transmission device having the above configuration during normal operation will be described. The signal transmission device receives a reception signal from an external remote controller through the signal lines L1 and L2. In this case, the polarity determination by the polarity detection circuit 10 and the polarity determination unit 21 and the auxiliary polarity determination by the auxiliary polarity determination unit 11a are alternately performed while being shifted by a fixed delay time.
[0039]
For example, first, when the pulse-like transmission signal P1 (FIG. 3) is received on the first signal line L1, the transmission signal P2 (FIG. 3) maintained near the ground potential is applied to the second signal line L2. ) Is received, and in this case, only the first light emitting diode PHD1 of the polarity detection circuit 10 emits light. Then, in the polarity detection circuit 10, only the first phototransistor PHT1 detects the light from the first light emitting diode PHD1, and based on this, the polarity determination means 21 determines that the first signal line L1 is positive. Judgment is made, and the switching of the signal changeover switch 14 is controlled in accordance with the judgment.
[0040]
Conversely, when the pulsed transmission signal P1 (FIG. 3) is received on the second signal line L2, the transmission signal P2 (FIG. 3) maintained near the ground potential is applied to the first signal line L1. ) Is received, and in this case, only the second light emitting diode PHD2 of the polarity detection circuit 10 emits light. Then, in the polarity detection circuit 10, only the second phototransistor PHT2 detects light from the second light emitting diode PHD2, and based on this, the polarity determination means 21 in the microcomputer 11 determines whether the second signal line L2 is It is determined that it is the positive electrode, and the switching of the signal switch 14 is controlled accordingly.
[0041]
After such polarity determination by the polarity detection circuit 10 and the polarity determination means 21, auxiliary polarity determination by the auxiliary polarity determination unit 11a is performed. However, when the respective elements PHD1, PHD2, PHT1, and PHT2 of the polarity detection circuit 10 are normal (if not faulty), the auxiliary polarity determination result by the auxiliary polarity determination unit 11a is determined by the polarity detection circuit 10 and the polarity determination unit 21. Since it matches the determination result, a detailed description thereof is omitted here. The detailed operation of the auxiliary polarity determination unit 11a will be described later.
[0042]
<Operation when polarity detection circuit 10 fails>
Next, an operation when each of the components PHD1, PHD2, PHT1, and PHT2 of the polarity detection circuit 10 fails will be described. Here, for the sake of simplicity, the case where all the elements PHD1, PHD2, PHT1 and PHT2 have failed will be described. It goes without saying that the unit 11a performs the same operation.
[0043]
Also in this case, the determination operation of the polarity detection circuit 10 and the polarity determination unit 21 and the determination operation of the auxiliary polarity determination unit 11a are alternately and repeatedly performed. However, here, the polarity detection circuit 10 is out of order, and the polarity determination unit 21 cannot determine the polarity of the signal lines L1 and L2. Thus, the switching control means 24 does not control the switching of the signal changeover switch 14. Therefore, during the determination timing by the polarity determination means 21, the signal changeover switch 14 remains held at the previous state.
[0044]
Next, polarity determination is performed by the auxiliary polarity determination unit 11a.
[0045]
That is, first, a reception signal (exemplified in FIG. 5A) is given from the external remote controller to the signal lines L1 and L2 through the transmission and reception ports P and N. Simultaneously with the reception of the received signal, an arbitrary signal output instructing means 22 of the microcomputer 11 gives an instruction to the transmission / reception block 15 to output an arbitrary transmission signal from the positive transmission A terminal Qa1.
[0046]
Here, in the connection with the external remote controller, when the correct external connection of the transmission / reception ports P and N is performed, that is, the positive transmission line is provided on the positive transmission / reception port P side, and the negative transmission / reception port N is provided. Are connected to each other (hereinafter referred to as “positive connection state”), and the switching state of the signal changeover switch 14 is adapted to the polarity of the “positive connection state” ( In this case, the reception signal (FIG. 5A) given from the external remote controller through the transmission / reception port P is transmitted to the first signal line L1. Any transmission signal (FIG. 5B) given from the positive transmission A terminal Qa1 through the signal changeover switch 14 is superimposed and recognized.
[0047]
Note that the received signal (FIG. 5A) and an arbitrary transmission signal (FIG. 5B) do not always have the same waveform, but the first signal line L1 has a value of “0”. Since the pulse waveforms shown always appear alternately, the two signals are regularly superimposed according to the pulse waveforms. That is, when the data of one unit of the received signal is, for example, “1, 0, 0, 1, 1, 0, 0, 1”, as shown in FIG. 5A, “No amplitude, negative, positive, amplitude” No amplitude, no amplitude, negative, positive, no amplitude ". If a positive amplitude appears, it always appears at an odd number, and if a negative amplitude appears, it always appears at an even number. When the data of one unit of transmission signal is, for example, "0, 1, 0, 0, 1, 0, 1, 0", as shown in FIG. 5B, "positive, no amplitude, positive, negative, A waveform such as "no amplitude, negative, no amplitude, negative" appears, and if a positive amplitude appears, it always appears at an odd number, and if a negative amplitude appears, it always appears at an even number. That is, the code arrangement of each bit of the reception signal and the transmission signal coincides in the positive direction and the negative direction, and even if they are superimposed, they cannot be canceled. That is, when the switching of the signal changeover switch 14 is “adapted” to the polarity, when the transmission signal and the reception signal are superimposed to form a combined pattern, the amplitude of the amplitude in the transmission signal from the transmission / reception block 15 is obtained. Are not offset. FIG. 6 is a diagram showing a combined pattern in this case. Bits indicated by (0) in FIG. 6 indicate the amplitude “0” values included in the transmission signal in FIG. 5B. Corresponds to bits.
[0048]
The combined pattern in the first signal line L1 is input to the reception A terminal Qa2 of the transmission / reception block 15 through the signal switch 14. In this case, the voltage level of the second signal line L2 is inverted and input to the reception B terminal Qb2, but the second signal line L2 is supplied from an external remote controller as a voltage substantially equal to the ground voltage. The maintained constant voltage state is maintained, and there is almost no effect on the combined pattern shown in FIG.
[0049]
As shown in FIG. 6, in the transmission signal transmitted from the transmission / reception block 15 in accordance with the instruction of the signal output instruction means 22, all the bits in the composite pattern corresponding to the bits having the value "0" appear as amplitude bits. . Therefore, the amplitude level detecting means 23 compares the amplitude values of the bits in these combined patterns with a constant reference amplitude value Th, and compares all the bits corresponding to the "0" value of the transmission signal (( If it can be confirmed that the amplitude value of (0) mark) is larger than the reference amplitude value Th (marked by ◎ in FIG. 6), the switching state of the signal changeover switch 14 is “compatible” with respect to the polarities of the signal lines L1 and L2. , And the switching state of the signal changeover switch 14 is maintained as it is.
[0050]
Next, although the external connection of the transmission / reception ports P and N is in the “normal connection state”, the switching state of the signal changeover switch 14 is a state suitable for the polarity of the “reverse connection state” (hereinafter “the connection state”). The state is referred to as “reverse switching state”). In this case, the reception signal received from the external remote controller is as shown in FIG. 5A, and the transmission signal transmitted from the transmission / reception block 15 is as shown in FIG. 5B.
[0051]
In this case, the first signal line L1 receives the reception signal shown in FIG. 5A, and the second signal line L2 is supplied from an external remote controller as a voltage substantially equal to the ground voltage. The state of the constant voltage (reference P2 in FIG. 3) and the transmission signal from the transmission / reception block 15 appear superimposed.
[0052]
When the signal is input to the reception A terminal Qa2 and the reception B terminal Qb2 of the transmission / reception block 15 through the signal changeover switch 14, the waveform of the second signal line L2 is a non-inverted signal, and the waveform of FIG. The data is input as shown in FIG. On the other hand, the waveform of the first signal line L1 is inverted as shown in FIG. Then, inside the transmission / reception block 15, they are superimposed on each other to form a combined pattern as shown in FIG. The bit indicated by (0) in FIG. 8 corresponds to the bit of the amplitude “0” value included in the transmission signal in FIG. 5B.
[0053]
Here, in FIG. 7A, the received signal which is the code sequence data of “1, 0, 0, 1, 1, 0, 0, 1” is “no amplitude, positive, negative, no amplitude, amplitude None, positive, negative, no amplitude ". If a positive amplitude appears, it always appears at an even number, and if a negative amplitude appears, it always appears at an odd number. This is opposite to the case of FIG. 5A. The transmission signal (FIG. 7B), which is code sequence data of “0, 1, 0, 0, 1, 0, 1, 0”, is “positive, no amplitude” as in the case of FIG. , Positive, negative, no amplitude, negative, no amplitude, negative ". If a positive amplitude appears, the waveform always appears at an odd number, and if a negative amplitude appears, it always appears at an even number. That is, the code arrangement of each bit of the reception signal and the transmission signal is opposite in the positive direction and the negative direction, and if these are superimposed, both the transmission signal and the reception signal happen to be " When a "0" value is taken, the bit is canceled at that timing. That is, when the switching of the signal changeover switch 14 is "not suitable" with respect to the polarity, when the transmission signal and the reception signal are superimposed to form a combined pattern, as shown by the mark x (cancellation bit) in FIG. Then, some amplitude bits in the transmission signal from the transmission / reception block 15 are canceled.
[0054]
In connection with an external remote controller, a state in which the transmission / reception ports P and N are externally connected to each other (hereinafter, referred to as a “reverse connection state”; The transmission state of the signal changeover switch 14 is “positive switching state” (that is, the signal transmission path is connected to the negative transmission / reception port N and the transmission path of the positive polarity is connected to the negative transmission / reception port N). When the changeover state of the changeover switch 14 is incompatible with the reverse connection state), the external signal is applied to the first signal line L1 as a voltage substantially equal to the ground voltage. The constant voltage state and an arbitrary transmission signal provided from the positive transmission A terminal Qa1 of the transmission / reception block 15 through the signal changeover switch 14 are superimposed, and a signal having a waveform as shown in FIG. 7B appears. Further, on the second signal line L2, a received signal similar to that shown in FIG. 5A given from an external remote controller appears as it is. When the signals of the signal lines L1 and L2 are input to the reception A terminal Qa2 and the reception B terminal Qb2 of the transmission / reception block 15 through the signal changeover switch 14, respectively, the waveform of the first signal line L1 is a non-inverted signal. 7A, the waveform of FIG. 7A is maintained, but the waveform of the second signal line L2 is inverted to become as shown in FIG. Recognized as a pattern. At this time, the sign of each bit of the waveform of FIG. 7A input non-inverted from the first signal line L1 and the waveform of FIG. 7B input inverted after being input from the second signal line L2 The arrangement is reversed in the positive and negative directions, and if they were superimposed, some bits would cancel. That is, when the switching of the signal changeover switch 14 is “not suitable” with respect to the polarity, when the transmission signal and the reception signal are superimposed to form a composite pattern, the transmission / reception block shown in FIG. Some amplitude bits in the transmitted signal from 15 are canceled.
[0055]
Further, when the external connection between the transmission / reception ports P and N is in the “reverse connection state” and the switching state of the signal changeover switch 14 is in the “reverse switching state”, the first signal line L1 is almost grounded. It becomes a state of a constant voltage given from an external remote controller as a voltage equal to the voltage. The second signal line L2 receives a reception signal (FIG. 5A) given from an external remote controller through the transmission / reception port P and a signal from the positive transmission A terminal Qa1 of the transmission / reception block 15 through the signal changeover switch 14. The transmitted arbitrary transmission signal (FIG. 5B) is superimposed and input. The composite pattern in the second signal line L2 appears as a waveform having a large amplitude as shown in FIG. 6, and is input to the reception A terminal Qa2 of the transmission / reception block 15 through the signal switch 14 as a non-inverted input signal. . In addition, the voltage level of the first signal line L1 is also inverted and input to the reception B terminal Qb2. The voltage of the first signal line L1 is substantially equal to the ground voltage.
[0056]
FIG. 9 shows these correspondences. As shown in FIG. 9, when the transmission and reception ports P and N are in the normal connection state and the signal changeover switch 14 is in the normal switching state, when the transmission and reception ports P and N are in the reverse connection state and the signal changeover switch 14 is in the reverse switching state. At that time, that is, when the switching state of the signal changeover switch 14 is a state suitable for the connection state of the transmission / reception ports P and N, there is no offset bit in the combined pattern. On the other hand, when the signal switch 14 is in the reverse switching state despite the transmission / reception ports P and N being in the normal connection state, and when the transmission / reception ports P and N are in the reverse connection state. When the signal changeover switch 14 is in the normal changeover state, that is, when the changeover state of the signal changeover switch 14 is incompatible with the connection state of the transmission / reception ports P and N, there is a cancellation bit in the combined pattern. become.
[0057]
Therefore, in the amplitude level detecting means 23, if at least one canceling bit (x in FIG. 8) is present in the bits of the composite pattern corresponding to the bit of the amplitude “0” in the transmission signal, Since it has been determined that the polarity correspondence of the signal changeover switch 14 to the signal lines L1 and L2 is reversed, the changeover control means 24 switches the signal changeover switch 14 from the current state to the opposite side. Thereafter, a transmission signal is transmitted between the indoor unit and the remote controller through the signal transmission device, and a predetermined control operation may be performed.
[0058]
In the operation of the auxiliary polarity determination unit 11a, if the transmission signal does not include the value “0”, it is not possible to detect whether the combined pattern has been canceled, but the transmission signal is permanently “1”. Since it is impossible to transmit only the value and the "0" value is output at a substantially constant frequency, the "0" value that happens to appear in the transmission signal of this arbitrary pattern is canceled out in the composite pattern. It is only necessary to continue to determine whether or not the signal changeover switch 14 is switched through the changeover control means 24 when it happens to synchronize with the “0” value in the externally received signal.
[0059]
As described above, in the signal transmission device according to the present embodiment, separately from the polarity detection circuit 10, the received signal from the outside and the arbitrary transmission signal transmitted from the transmission / reception block 15 are collated to form a composite pattern. It is possible to easily determine whether or not the switching state of the signal switch 14 with respect to the connection state of the transmission / reception ports P and N is appropriate only by detecting whether or not there is an offset bit. However, it is possible to easily determine the suitability of the signal changeover switch 14 and automatically perform the changeover control.
[0060]
In the above-described embodiment, the signal transmission device is described as being installed in the indoor unit and transmitting and receiving a transmission signal to and from the remote controller. Or transmission and reception of transmission signals with an indoor unit installed in an outdoor unit. In particular, when a plurality of indoor units are connected to a single or a plurality of outdoor units through a predetermined network, it is effective to apply the invention to signal transmission between these outdoor units and the indoor units.
[0061]
【The invention's effect】
According to the invention described in claims 1 to 7, first, in principle, When the received signal includes a bit of amplitude, in a predetermined unit of the received signal, so that a pulse waveform indicating the bit of the amplitude appears at alternating positive and negative timing, When a reception signal is applied to the first signal line and the second signal line from the outside via a transmission line, the level of the potential of the first signal line and the level of the potential of the second signal line are determined by a predetermined polarity detection circuit. The polarities of both signal lines are detected by comparison, and the signal changeover switch is switched and driven in accordance with the detected polarities, so that the transmission / reception of the first signal line and the second signal line is performed. Step Switching between the inverting and non-inverting relations to each other, and then, when a predetermined reception signal is externally applied to either the first signal line or the second signal line via the transmission line, the signal switching is performed. To one signal line on the side connected without inversion by a switch , The pulse waveform including the bit with the amplitude and indicating the bit with the amplitude in the same unit as the received signal is set so as to appear at the alternating timing of positive and negative. Any transmission signal At the timing corresponding to the reception of each unit of the received signal. In parallel with this, the signal of one signal line on the side connected without inversion and the signal of the other signal line connected and inverted are superimposed to form a combined pattern, Recognize the amplitude value of each bit of the composite pattern and, based on the result of recognizing the amplitude value of each bit of the composite pattern, detect whether any of the bits in the composite pattern have any canceled bits, and cancel them. When there is no bit that has been set, the first and second signal lines of the signal changeover switch maintain the inverted and non-inverted relationship with respect to the transmitting / receiving means, while the bit canceled out of the bits in the combined pattern. In the case where there is a signal changeover switch, the inverting and non-inverting relationship of the first signal line and the second signal line with respect to the transmitting / receiving means is changed and switched, so that the polarity detection circuit fails. Even Can be performed without any trouble polarity determination, there is an effect that the switching of the signal changeover switch according to the determination result can be easily performed.
[0062]
This invention is effective for transmission between an indoor unit, an outdoor unit and an operation unit for remote control of the air conditioner as described in claims 4 to 6.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a signal transmission device according to one embodiment of the present invention.
FIG. 2 is a diagram showing a signal waveform in one embodiment of the present invention.
FIG. 3 is a diagram showing signal waveforms in one embodiment of the present invention.
FIG. 4 is a block diagram showing a connection relationship in one embodiment of the present invention.
FIG. 5 is a waveform diagram showing a state before combining signals applied to the reception terminals of the transmission / reception block according to one embodiment of the present invention;
FIG. 6 is a waveform chart showing a state after combining signals applied to the reception terminals of the transmission / reception block according to one embodiment of the present invention;
FIG. 7 is a waveform diagram showing a state before combining signals applied to the reception terminals of the transmission / reception block according to one embodiment of the present invention;
FIG. 8 is a waveform diagram showing a state after combining signals applied to the reception terminals of the transmission / reception block according to one embodiment of the present invention;
FIG. 9 is a diagram showing the operation of one embodiment of the present invention.
FIG. 10 is a block diagram showing a conventional signal transmission device.
[Explanation of symbols]
Reference Signs List 10 polarity judgment circuit, 11 microcomputer, 14 signal changeover switch, 15 transmission / reception block, 21 polarity judgment means, 22 signal output instruction means, 23 amplitude level detection means, 24 switching control means, P, N transmission / reception port, L1 first signal Line, L2 second signal line, PHD1, PHD2 light emitting diode, PHT1, PHT2 phototransistor

Claims

A signal transmission device for transmitting a signal to and from a predetermined external device,
A first signal line (L1) and a second signal line (L2) to which a pair of transmission lines are connected;
Transmitting / receiving means (15) connected to one of the two signal lines (L1, L2) without inversion and inverting to the other signal line to transmit and receive signals;
A signal changeover switch (14) for mutually switching an inverting and non-inverting relationship of the first signal line (L1) and the second signal line (L2) with respect to the transmitting / receiving means (15);
Together give an indication of transmission and reception operation of the reception block (15), the control unit for instructing the connection switching of the signal changeover switch based on the received signal received (14) in front Symbol transceiver block (15) and (11) Prepare,
When the received signal includes a bit of amplitude, the pulse waveform indicating the bit of the amplitude within a predetermined unit of the received signal is set to appear at alternating positive and negative timing,
Wherein the control unit (11), the external through the transmission line and the first signal line (L1) and the when the reception signal is supplied to the second signal line (L2), the signal changeover switch (14) A pulse waveform including amplitude bits and indicating the amplitude bits in the same unit as the reception signal appears at the alternately positive and negative timings on the one signal line on the side connected without being inverted by An arbitrary transmission signal set as described above is provided at a timing corresponding to reception of each unit of the reception signal, and is inverted and connected to the signal of the one signal line on the side connected without inversion. The signal of the other signal line is superimposed to form a combined pattern, and when there is a canceled bit among the bits in the combined pattern, the signal switch (14) is connected to the first signal line (L1). And the said Signal line (L2) of said receiving means (15) signal transmission apparatus characterized by having a function to instruct to change switched mutually inverting and non-inverting relationship to the.

The signal transmission device according to claim 1,
A polarity detection circuit (10) for comparing the potential of the first signal line (L1) and the potential of the second signal line (L2) to detect the polarity of both signal lines (L1, L2); Prepare,
The signal transmission device according to claim 1, wherein the control unit (11) further has a function of controlling switching of the signal changeover switch (14) based on a detection result of the polarity detection circuit (10).

The signal transmission device according to claim 2, wherein
The control unit (11) includes:
Polarity determination means (21) for determining the polarity of the signal changeover switch (14) based on the detection result of the polarity detection circuit (10);
Signal output instructing means (22) for instructing the transmission / reception block (15) to output the transmission signal to the one signal line on the side connected without inverting the arbitrary transmission signal through the transmission / reception block (15). )When,
The signal output instructing means (22) detects the amplitude value of each bit in the composite pattern when the arbitrary transmission signal is output, and based on the detection result, cancels out the bit offset among the bits. Amplitude level detecting means (23) for detecting whether or not there is;
The signal switching switch (14) is switched and controlled according to the result of the determination by the polarity determining means (21), and the signal switching is performed when the amplitude level detecting means (23) has a bit canceled in the composite pattern. Switching control means 24 for giving an instruction to change and switch the inversion and non-inversion relations of the switch (14) with respect to the first signal line (L1) and the second signal line (L2). A signal transmission device.

2. The signal transmission device according to claim 1, wherein the signal transmission device is provided in an indoor unit of the air conditioner, and is used for signal transmission with an operation unit that remotely controls an operation of the air conditioner. 3. A signal transmission device characterized by the above-mentioned.

2. The signal transmission device according to claim 1, wherein the signal transmission device is provided in an indoor unit of the air conditioner, and is used for signal transmission with the outdoor unit of the air conditioner. 3. Signal transmission device.

2. The signal transmission device according to claim 1, wherein the signal transmission device is provided in an outdoor unit of the air conditioner, and is used for signal transmission with the indoor unit of the air conditioner. 3. Signal transmission device.

When there is a bit with a large amplitude in a predetermined unit, a reception signal set so that a pulse waveform indicating the bit with a large amplitude appears at an alternately positive and negative timing is externally supplied to a first signal line ( when given the obtained in L1) and a second signal line (L2), said first signal line (L1) potential in height a predetermined polarity detection circuit of the potential of the second signal line (L2) of The comparison is made in (10) to detect the polarity of both signal lines (L1, L2), and the signal changeover switch (14) is switched and driven in accordance with the detected polarity, so that the first signal line (L1) and A first step of mutually changing and switching the inversion and non-inversion relation of the second signal line (L2) with respect to the transmission / reception means (15);
When a reception signal is applied to the first signal line (L1) and the second signal line (L2) from outside via a transmission line, one of the sides connected without being inverted by the signal changeover switch (14) An arbitrary transmission signal that includes a bit with amplitude and a pulse waveform that indicates the bit with amplitude in the same unit as the reception signal is set to appear at alternating positive and negative timings. A second step of giving at a timing corresponding to the reception of each unit of
In parallel with the second step, the signal of the one signal line on the side connected without inversion and the signal of the other signal line connected in reverse are superimposed to form a combined pattern, A third step of recognizing the amplitude value of each bit of the composite pattern;
Based on the result of recognizing the amplitude value of each bit of the composite pattern, it is detected whether or not there is a canceled bit among the bits in the composite pattern. The signal switch (14) maintains the inversion and non-inversion relationship of the first signal line (L1) and the second signal line (L2) with respect to the transmission / reception means (15), while maintaining the bit in the composite pattern. When there is a canceled bit in the signal, the signal changeover switch (14) inverts and disables the first signal line (L1) and the second signal line (L2) with respect to the transmission / reception means (15). And a fourth step of mutually changing and switching the inversion relationship.