JP3588936B2 - Flexible high-speed multiplexed remote input / output system - Google Patents

Description

【００３４】
アナログ値の場合、３データ受信時には中間値が採用され、２データ受信時にはフェイルセーフ側の値が採用される。デジタル値の場合、３データ受信時には多数決による値が採用され、２データ受信時にはフェイルセーフ側の値が採用される。いずれの場合も、１データ受信時にはそのデータ、受信データ無しの場合は前回値が採用される。ただし、１データ以下受信時については、この決定規則による出力は表１のとおりであるが、受信チェックにおいてデータ受信の異常と判定され、結果的に出力が行われないこともある。
【００３５】
次に、二重化通信による入力信号の流れを説明する。図４に示されるように、入出力デバイスの状態や値は入力インターフェース基板を介し、Ａ系、Ｂ系それぞれの入出力基板、例えばアナログ入力基板（ＡＩ）２３２に入力され、その入力信号はそれぞれの通信路を介して制御モジュールのＶＭＥバス通信基板２２１に送信される。ＣＰＵ基板２２２では、入力処理として各々のデュアルポートメモリ（ＤＰＭ）からＡ系、Ｂ系の入力信号を読み出し、表２の選択ルールに従い入力信号を択一採用する。
【００３６】
【表２】

【００３７】
表２中、正常／異常は、受信チェック及び自己診断結果に基づくものである。詳細は後述するが、受信チェック結果は入力信号の受信が正しく行われたかどうかを示し、自己診断結果は入出力基板からＶＭＥバス通信基板２２１までの各々の基板が正しく動作しているかを示す。表２から判るように、Ａ系、Ｂ系の入力信号のうち正常な通信系の入力信号が採用されるが、両方正常のときはＡ系が優先される。
【００３８】
次に、二重化通信による出力信号の流れを説明する。図５に示されるように、制御モジュールのＣＰＵ基板２２２からＡ系、Ｂ系のＶＭＥバス通信基板２２１に同じ出力信号が渡され、その出力信号はそれぞれの通信路を介して入出力基板、例えばアナログ出力基板（ＡＯ）２３３に送信され、さらに出力インターフェース基板に送信される。このとき入出力基板から出力インターフェース基板に対し、出力信号に加えて選択信号が出力される。この選択信号は、正常／異常の二値を取り、その値は受信チェック及び自己診断結果に基づくものである。受信チェック結果は出力信号の受信が正しく行われたかどうかを示し、自己診断結果は、光信号変換基板及び入出力基板が正しく動作しているかを示す。入出力インターフェース基板では、表３の選択ルールに従い出力信号を択一採用して入出力デバイスに出力する。
【００３９】
【表３】

【００４０】
表３から判るように、Ａ系、Ｂ系の入力信号のうち正常な通信系の入力信号が採用されるが、両方正常のときはＡ系が優先される。
【００４１】
受信チェックは、通信路を挟む結合部及び拠点部の光信号変換基板が行うもので、時間監視、即ち互いに所定時間内に入出力信号のデータを受信するかどうかの監視と、冗長検査とがある。時間監視については自己診断の詳細に併せて説明する。冗長検査には、公知のＣＲＣ検査が用いられる。また、チェックサムによる検査も併用される。
【００４２】
次に、自己診断、時間監視及び自己較正の詳細を説明する。
【００４３】
ＶＭＥバス通信基板（ＣＰＵ動作確認）
図６に示されるように、ＶＭＥバス通信基板２２１ではＣＰＵの定期的動作確認が行われる。即ち、ＶＭＥバス通信基板上のＣＰＵ２２１１が実行する制御プログラムから例えば１０ｍｓｅｃ周期でリセットパルスが出力され、ウォッチドッグタイマ２２１２をリセットする。リセットパルスが出力されないとき、ウォッチドッグタイマ２２１２は１５ｍｓｅｃでタイムアップとなり、ＶＭＥバス２２３に異常ステータスが出力される。この異常ステータスは、同一ＶＭＥラック中のＣＰＵ基板２２２が読み取りＤＯ基板２２４に出力する。ＤＯ基板２２４は、ＶＭＥラック挿入側のスロットＬＥＤ２２５を点灯させると共に制御盤１２１正面扉のモジュール異常ランプ１２１１を点灯させる。なお、ＶＭＥバス通信基板２２１には３つのＣＰＵ２２１１が搭載されているので、ウォッチドッグタイマ２２１２も３つ設けられ、３者の出力の論理和が異常ステータスとなる。
【００４４】
入出力基板（ＣＰＵ動作確認）
図７に示されるように、各入出力基板にはそれぞれＣＰＵ２３０１が搭載されている。このＣＰＵ２３０１に対してもウォッチドッグタイマ２３０２が設けられている。各入出力基板の異常ステータスは、いったんデジタル入力基板２３４に渡され、デジタル入力基板より光信号変換基板２３１，２１１及び通信路経由でＶＭＥバス通信基板２２１に伝送され、さらにＶＭＥバス２２３経由で制御モジュールのＣＰＵ基板２２２に通知される。ＣＰＵ基板２２２からは操作コンソール１３３，１３４にイベントメッセージが送信される。
【００４５】
アナログ入力基板
図８に示されるように、アナログ入力基板２３２にはＡ／Ｄ変換器（ＡＤＣ）２３２１が設けられている。このＡ／Ｄ変換器２３２１は入出力デバイスからのアナログ入力の他に基準レベルが読み取れるようになっている。基準レベルは、アナログ入力基板内の基準電圧１０ｖをラダー抵抗回路２３２２で複数等分し、各分点の電圧をそれぞれ基準電圧としてアナログスイッチ２３２３で切り替え入力できるようになっている。ここでは基準電圧は、１０，８，６，４，２ｖである。アナログスイッチ２３２３の後段に−２演算器及び×１．２５演算器が挿入されているので、Ａ／Ｄ変換器２３２１には１０，７．５，５，２．５，０ｖが入力される。このようにして読み取った基準レベルのデジタル値に対し、ＣＰＵ２３２４には固定のデジタル基準値が用意されており、両者の差が所定の許容範囲にあるかどうか判定される。ここでは、各レベルの比較結果が論理和されて異常ステータスとなる。この異常ステータスは、いったんデジタル入力基板２３４に渡され、デジタル入力基板２３４より光信号変換基板２３１，２１１及び通信路経由でＶＭＥバス通信基板２２１に伝送され、さらにＶＭＥバス２２３経由で制御モジュールのＣＰＵ基板２２２に通知される。ＣＰＵ基板２２２からは操作コンソール１３３，１３４にイベントメッセージが送信される。
【００４６】
アナログ出力基板
図９に示されるように、アナログ出力基板２３３には複数個のＤ／Ａ変換器２３３１が設けられている。そして、これらのＤ／Ａ変換器出力を切り替えて読み取ることのできるループバックテスト用のＡ／Ｄ変換器２３３２が設けられている。ＣＰＵ２３３３は、Ｄ／Ａ変換器２３３１の出力をＡ／Ｄ変換器２３３２によって読み取り、出力したデジタル値と読み取ったデジタル値との差が所定の許容範囲にあるかどうか判定する。異常ステータスは、いったんデジタル入力基板２３４に渡され、デジタル入力基板２３４より光信号変換基板、通信路経由でＶＭＥバス通信基板２２１に伝送され、さらにＶＭＥバス経由で制御モジュールのＣＰＵ基板２２２に通知される。ＣＰＵ基板２２２からは操作コンソール１３３，１３４にイベントメッセージが送信される。
【００４７】
デジタル入力基板
図１０に示されるように、デジタル入力基板２３４には二値状態入力のための入力バッファ２３４１が設けられている。この入力のラインには、電圧側と接地側とにそれぞれ短絡用トランジスタ２３４２，２３４３が設けられている。ＣＰＵ２３４４は、入出力デバイスからの入力の周期の合間に、全状態入力を強制的にオンオフする。このタイミングで読み取った強制状態値が強制したとおりになっていなければ異常と判定する。異常ステータスは、デジタル入力基板（自基板、又は別途基板）２３４に渡され、デジタル入力基板２３４より光信号変換基板、通信路経由でＶＭＥバス通信基板２２１に伝送され、さらにＶＭＥバス経由で制御モジュールのＣＰＵ基板２２２に通知される。ＣＰＵ基板２２２からは操作コンソール１３３，１３４にイベントメッセージが送信される。
【００４８】
デジタル出力基板
図１１に示されるように、デジタル出力基板２３５には、二値制御出力のための出力レジスタ２３５１が設けられている。出力レジスタ２３５１の出力はループバックして読み取れるようになっている。ＣＰＵ２３５２は、出力した二値制御出力とループバックして読み取った内容との比較が一致しなければ異常と判定する。異常ステータスは、いったんデジタル入力基板２３４に渡され、デジタル入力基板２３４より光信号変換基板、通信路経由でＶＭＥバス通信基板２２１に伝送され、さらにＶＭＥバス経由で制御モジュールのＣＰＵ基板２２２に通知される。ＣＰＵ基板２２２からは操作コンソール１３３，１３４にイベントメッセージが送信される。
【００４９】
なお、図７〜図１１において、各入出力基板の異常ステータスは、いったんデジタル入力基板２３４に渡されるが、この異常ステータスは自己診断結果として受信チェック結果と共に選択信号となり、出力インターフェース基板に対して出力される。このように、自己診断結果はインターフェース部２４０及び制御盤１２０のそれぞれで利用されることになる。また、各入出力基板において自己診断は入出力の周期の合間に行われるので、自己診断を行ったことによる入出力時間の遅れは生じない。
【００５０】
ＶＭＥバス通信基板（受信時間監視）
図１２に示されるように、ＶＭＥバス通信基板２２１には受信オーバータイム監視回路２２１３が設けられている。受信オーバータイム監視回路２２１３は、機器側からの伝送周期２０ｍｓｅｃに対し２００ｍｓｅｃの期限を設定し、この期限内に受信がなければデュアルポートメモリ２２１４に異常ステータスを立ち上げ、この異常ステータスを同一ＶＭＥラック中のＣＰＵ基板２２２が読み取りＤＯ基板２２４に出力する。ＤＯ基板２２４は、制御盤正面扉の通信異常ランプ１２１２を点灯させることもある。また、ＣＰＵ基板２２２からは操作コンソール１３３，１４４にアラームメッセージが送信される。
【００５１】
光信号変換基板（受信時間監視）
図１３に示されるように、光信号変換基板２１１，２３１には受信オーバータイム監視回路２００１，２００２が設けられている。受信オーバータイム監視回路は、電気信号側と光信号とにそれぞれ設けられている。予めジャンパ端子アレイ２００３，２００４のジャンパによって期限が設定されている。一度受信があってからこの期限内に次の受信がなければ異常ステータスを立ち上げ、この異常ステータスを制御モジュール２２０中のデジタル入力基板又は拠点部２３０中のデジタル入力基板に渡す。ＣＰＵ基板はデジタル入力基板の入力を読み取って、操作コンソールにイベントメッセージを送信する。
【００５２】
デジタル出力基板（受信時間監視）
図１４に示されるように、デジタル出力基板２３５には伝送異常検出ロジック２３５３が組み込まれている。伝送異常検出ロジック２３５３は、３個の制御モジュールからの出力信号について、それぞれパラメータ設定された期限を有し、この期限内に次の受信がなければ、その制御モジュールを伝送異常とし、１つ以上の制御モジュールが伝送異常ならばＬＥＤを点灯、２つ以上の制御モジュールが伝送異常ならば異常ステータスを出す。異常ステータスは、いったんデジタル入力基板２３４に渡され、デジタル入力基板２３４より光信号変換基板、通信路経由でＶＭＥバス通信基板２２１に伝送され、さらにＶＭＥバス経由で制御モジュールのＣＰＵ基板２２２に通知される。ＣＰＵ基板２２２からは操作コンソールにイベントメッセージが送信される。制御モジュールが単一の場合は、その制御モジュールが伝送異常ならば直ちに異常ステータスを出す。
【００５３】
アナログ入力基板（アナログ入力自己較正）
図８において既に説明したように、アナログ入力基板２３２のＡ／Ｄ変換器２３２１はラダー抵抗回路２３２２による複数の基準レベル（基準電圧、１０，８，６，４，２ｖ）が読み取れるようになっている。これらの基準レベルのＡ／Ｄ変換値を用いてアナログ入力の自己較正を行う。このためには、予め（例えばアナログ入力基板を制作した時点で）ラダー抵抗回路２３２２による基準電圧を計測器により厳密に測定し、その厳密測定値に対する理想的なＡ／Ｄ変換値を計算して電気的消去可能な読み出し専用メモリ（ＥＥＰＲＯＭ、図示せず）に書き込んでおく。ＣＰＵ２３２４は、上記厳密測定値に対する理想的なＡ／Ｄ変換値により折れ線データを作成し、入出力デバイスからのアナログ入力のＡ／Ｄ変換値を折れ線データに当てはめ、補正する。
【００５４】
アナログ出力基板（アナログ出力自己較正）
前記アナログ入力基板の自己較正と同様に複数点のデータによる折れ線近似を用いる。このために、図９に示したアナログ出力基板２３３において、Ｄ／Ａ変換器２３３１に対しデジタル値を最小分解能きざみで最小値から最大値まで増加させて出力し、それぞれの値ごとにループバックテスト用のＡ／Ｄ変換器２３３２で読み取り、これを予め求めてある係数により出力電流に換算し、出力電流が複数の値、例えば４，８，１２，１６，２０ｍＡになるときの各出力デジタル値を較正値としてＥＥＰＲＯＭに書き込んでおく。この複数の較正値は、実際に入出力デバイスへ出力したいアナログ値を得るために必要なデジタル値を求める折れ線データを形成する。ＣＰＵ２３３４は、出力したいデジタル値を上記折れ線データに当てはめて補正し、補正されたデジタル値をＤ／Ａ変換器２３３１に出力する。
【００５５】
次に、単一／多重選択について説明する。
【００５６】
図１５〜図１８に単一／多重選択の各種形態を示す。まず、図１５のものは、３個の制御モジュール（ＧＣＵ−１，ＧＣＵ−２，ＧＣＵ−３）と単一の制御モジュール（ＤＡＵ）との計４つの制御モジュール２２０を使用している。拠点部２３０のアナログ出力基板２３３及びデジタル出力基板２３５には、制御モジュールに対応する４つの受信部３１０が設けられ、各制御モジュール２２０から受信部３１０へ出力信号のデータが送信されるようになっている。各受信部３１０は、各々ＣＲＣチェック部３１１、タイムアウト監視部３１２、受信メモリ３１３を備えている。受信メモリ３１３の取り出し側には、ボーティングスイッチ３２１、単一／多重選択スイッチ３２２が設けられている。拠点部２３０から各制御モジュール２２０に対しては入力信号等からなるステータスが同報通信により送信されるようになっている。ボーティングスイッチ３２１は今までに述べたように決定規則に従って択一採用する機能を素子として表現したものである。各制御モジュールは、各々タイムアウト監視部４１１、複数チャネルのメモリ４１２を備えている。これによると、３個の制御モジュール（ＧＣＵ−１，ＧＣＵ−２，ＧＣＵ−３）からの三重系出力は拠点部２３０のボーティングスイッチ３２１においてチャネルごとに択一された後、単一／多重選択スイッチ３２２に渡される。他方、一重系出力はそのまま単一／多重選択スイッチ３２２に渡される。三重系か一重系かの選択は単一／多重選択スイッチ３２２においてチャネルごとに行われる。このようにして選ばれた出力がアナログ出力インタフェース基板（ＡＯ）２４２、デジタル出力インタフェース基板（ＤＯ）２４４に出力される。
【００５７】
図１６のものは、単一の制御モジュール（ＤＡＵ）からの出力信号が使用されず、代わりに３つの制御モジュール（ＧＣＵ−１，ＧＣＵ−２，ＧＣＵ−３）からの出力信号のうちのひとつが一重系出力に使用される。従って、単一の制御モジュール（ＤＡＵ）用の受信メモリも使用されず、三重系出力用の受信メモリ３１３の取り出し側のひとつが単一／多重選択スイッチ３２２に接続されている。拠点部２３０から各制御モジュール２２０に対しては入力信号等からなるステータスが同報通信により送信される。
【００５８】
図１７のものは、単一の制御モジュール（ＤＡＵ）からの出力信号のみが使用される。従って、三重系出力用のメモリ（斜線付きの部分）が使用されない。単一／多重選択スイッチ３２２は固定である。制御モジュール（ＤＡＵ）からの一重系出力は、そのままアナログ出力インタフェース基板（ＡＯ）２４２、デジタル出力インタフェース基板（ＤＯ）２４４に出力される。拠点部２３０から各制御モジュール２２０に対しては入力信号等からなるステータスが同報通信により送信される。
【００５９】
図１８のものは、一重系出力を２系統使用するものである。それぞれ単一の制御モジュール（ＤＡＵ，ＧＣＵ）が設けられ、拠点部２３０には対応する２つの受信部３１０が設けられる。両一重系の選択は選択スイッチ３２２においてチャネルごとに行われる。拠点部２３０から各制御モジュール２２０に対しては入力信号等からなるステータスが同報通信により送信される。
【００６０】
図１５〜図１８の各種形態は任意に選択できる。このようにして多重化は、入出力の重要度に鑑み多様に設定することができる。
【００６１】
【発明の効果】
本発明は次の如き優れた効果を発揮する。
【００６２】
（１）多重化された制御系に対し通信路は二系統でよいので、通信路のコストを低減することができる。
【００６３】
（２）制御盤側で受信チェックや自己診断の結果を用いて入力信号を択一するようにしたので、フォールトトレラント性を確保することができる。
【００６４】
（３）機器側で受信チェックや自己診断の結果を用いて出力信号を択一するようにしたので、フォールトトレラント性を確保することができる。
【００６５】
（４）個々の入出力基板でＣＰＵと入出力素子について自己診断を行うようにしたので、的確に異常を検出できると共に、その自己診断結果により択一される入出力信号の信頼性を高めることができる。
【００６６】
（５）複数段階の基準レベルによりアナログ入力の自己較正及び自己診断を行うので、精密な測定値が得られ、かつその測定値の信頼性は高い。
【００６７】
（６）受信の時間監視とデータの冗長検査とにより受信チェックを行うので、通信の信頼性を高めることができる。
【００６８】
（７）単一か多重かの選択ができるので、入出力信号の重要度に応じた任意の多重化が可能となる。
【図面の簡単な説明】
【図１】本発明の一実施形態を示すガスタービン発電プラントの構成図である。
【図２】図１のプラントにおけるフレキシブル高速多重化リモート入出力システムの基本構成図である。
【図３】本発明の三重化制御装置と拠点との間の入出力信号の流れを示す図である。
【図４】本発明の二重化通信による入力信号の流れを示す図である。
【図５】本発明の二重化通信による出力信号の流れを示す図である。
【図６】本発明のＶＭＥバス通信基板におけるＣＰＵ動作確認のための回路構成図である。
【図７】本発明の各入出力基板におけるＣＰＵ動作確認のための回路構成図である。
【図８】本発明のアナログ入力基板における基準レベルのＡ／Ｄ変換入力のための回路構成図である。
【図９】本発明のアナログ出力基板におけるループバックテストのための回路構成図である。
【図１０】本発明のデジタル入力基板における強制状態値入力のための回路構成図である。
【図１１】本発明のデジタル出力基板におけるループバックテストのための回路構成図である。
【図１２】本発明のＶＭＥバス通信基板における受信時間監視のための回路構成図である。
【図１３】本発明の光信号変換基板における受信時間監視のための回路構成図である。
【図１４】本発明のデジタル出力基板における受信時間監視のための回路構成図である。
【図１５】本発明の単一／多重選択の一形態による入出力信号の流れを示す図である。
【図１６】本発明の単一／多重選択の一形態による入出力信号の流れを示す図である。
【図１７】本発明の単一／多重選択の一形態による入出力信号の流れを示す図である。
【図１８】本発明の単一／多重選択の一形態による入出力信号の流れを示す図である。
【符号の説明】
１１０ 機器側（プラント系）
１２０ 制御盤側（制御系）
１４０ 通信路
２１０ 結合部
２２０ 制御モジュール
２３０ 拠点部
２４０ インターフェース部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention plural I / O signal Predetermined More specifically, the present invention relates to a multiplexing system which adopts an alternative method in accordance with a decision rule, and in particular, a flexible high-speed multiplexing remote input device which has reliability, reduces costs, has a self-diagnosis function, and has an arbitrary multiplexing function. It concerns the output system.
[0002]
[Prior art]
2. Description of the Related Art In a plant including various devices, a control panel for controlling devices by input / output signals is provided for input / output devices such as sensors and actuators mounted on the devices. For those requiring a high degree of reliability, such as gas turbine control, Board May have a fault-tolerant property such that the final control output will be correct even if there is a defect in some of the components. For this reason, for input / output devices such as sensors and actuators installed in the equipment, a control panel that controls the equipment based on the input / output signals has multiple control modules in parallel. Pieces Provided, each Control module A multiplexing system is employed in which input / output signals are selectively adopted (voting) in accordance with a decision rule such as a majority decision.
[0003]
In addition, the control panel may be provided at a location far away from a location where various devices are provided, and this requires a long-distance communication path.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional multiplex system, for example, if it is a triple system, Three control modules and three communication channels It is necessary to provide all input / output signals regardless of the importance of the input / output signals. three, Processed in three systems. This means that there is a useless portion in consideration of the plant cost or the simplicity of system construction. In other words, there is no merit in providing three systems of communication paths that have high reliability in themselves, and three Pieces This is because no processing is required.
[0005]
In a conventional multiplexing system, Each one, By adopting one of the input / output signals of each system, defective input / output signals are eliminated, Each one, It does not have a so-called self-diagnosis function for finding defects in each part of each system. Therefore, the occurrence of the defect is concealed, making it difficult to find out.
[0006]
In addition, there is no conventional multiplexing system in which input / output signals are selectively used on the device side.
[0007]
Therefore, an object of the present invention is to provide a flexible high-speed multiplexing remote input / output system which solves the above-mentioned problems, has reliability, reduces cost, has a self-diagnosis function, and has arbitrary multiplexing. Is to do.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a control panel for controlling a device based on input / output signals for input / output devices such as sensors and actuators provided in a plant device. Pieces Establishment Was In a multiplex system, two communication paths are provided between the equipment and the control panel, and both control paths are provided on the control panel side. All of The output signals of the control module are transmitted in order and the received input signals are each A coupling unit for distributing to the control module is provided, and an input signal is sequentially transmitted to the device side of both communication paths, and All of From the output signals received from the control module Predetermined Providing a base unit for selecting according to the decision rule, the control module selects one of the input signals distributed from the coupling unit of both system communication paths, the input / output device reads the input, It is connected to an interface unit that transfers the signal to the bases of both communication paths and selects and outputs one of the output signals from the bases of both communication paths.
[0009]
The base unit may adopt the alternative using the result of the reception check at the base unit in accordance with the decision rule.
[0010]
The selection and adoption of the input signal performed by the control module may be in accordance with a predetermined decision rule using the result of the self-diagnosis performed by the reception check and the base unit in each coupling unit.
[0011]
The alternative use of the output signal performed by the interface unit may be in accordance with a predetermined decision rule using the result of the reception check and the self-diagnosis performed by each base unit.
[0012]
The base unit includes an analog input board including a CPU and an A / D converter, an analog output board including a CPU and a D / A converter, and an input buffer for inputting a binary state. It has a digital input board and a digital output board equipped with a CPU and an output register for binary control output. For each board, it periodically checks the operation of the CPU, and performs A / D conversion input of a reference level, D / A The self-diagnosis may be performed by reading the A / D conversion of the converter output, inputting the forced state value or reading the output of the output register, and transmitting the self-diagnosis result to the interface unit and the control module.
[0013]
The base unit may have a plurality of reference levels for the analog input, and perform the self-calibration and the self-diagnosis of the analog input using the A / D conversion values of these reference levels.
[0014]
The base unit may measure in advance digital calibration values at which the analog output becomes a predetermined value in a plurality of stages by D / A conversion, correct the digital value with these calibration values, and then perform D / A conversion.
[0015]
The coupling section and the base section sandwiching the communication path may monitor reception of input / output signal data within a predetermined time with respect to each other and perform a reception check by checking the data redundancy.
[0016]
The above base unit fixes the output signal One control module Only adopt Multiple control modules Or a single / multiple selection switch for selecting whether to adopt the alternative.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0018]
The system of FIG. 1 applies the present invention to a gas turbine power plant. This system is roughly divided into a plant system 110, a control system 120, and a man-machine interface system 130. In the plant system 110, various devices such as a gas turbine main body 111, a generator 112, and accessories 113 are provided, and a remote I / O junction box (JB) 114 for transmitting and receiving input / output signals is provided. An optical cable 115 is laid over, for example, 2 km as a communication path 140 from the plant system 110 to the control system 120. The control system 120 includes a gas turbine controller control panel 121 and a generator panel 122. A man-machine interface system 130, which is a manned facility, includes a monitoring panel 131 in which instruments are collected, an operation panel 132 in which switches for operation are arranged, and primary and secondary operation consoles 133 and 134 using a general-purpose computer.
[0019]
FIG. 2 shows a flexible high-speed multiplexed remote input / output system (hereinafter, abbreviated as an input / output system) of the present invention from the above system. As shown, the input / output system is divided into a device side (plant system) 110 and a control panel side (control system) 120. A communication path 140 composed of an optical cable between the two is provided with two systems of A system and B system.
[0020]
An optical signal conversion board 211 is provided as a coupling section 210 on the control panel side of both communication paths. The station link unit (SLU) is a device that accommodates a large number of optical signal conversion boards 211. One coupling unit 210 has one communication path All (here 3) Are connected to the control module 220 (GCU-1, GCU-2, GCU-3). The coupling unit 210 Pieces The transmission order of each control module 220 is determined, and the signals transmitted from these control modules 220 can be converted into light and transmitted to the communication path 140. Also, the coupling unit 210 converts the input signal received from the communication path 140 into 3 Pieces Can be distributed to all the control modules 220 by simultaneous broadcast. Each control module 220 is provided with A-system and B-system VME bus communication boards (R-BUS boards) 221. The A-system VME bus communication board 221 is connected to the A-system coupling unit 210 and the B-system VME bus communication board. The VME bus communication board 221 is connected to the B-system coupling unit 210. In addition, a CPU board (main CPU) for performing a control operation using an input signal is provided in the control module, but the content of the control operation is not important here, so that it is omitted. Here, it is essential that the control module 220 performs the control operation by adopting either one of the input signals distributed from the coupling section 210 of the A-system and B-system communication paths. One R-BUS board 221 of each control module 220 is connected to three coupling units 210 having the same communication system. This is a configuration for enabling a three-base configuration for a base to be described later. One coupling unit 210 is provided for each of the A system and the B system for each base. Therefore, in a three-site configuration, there are a total of six coupling units 210 in the SLU.
[0021]
Stations (STN-1A, -1B, -2A,...) Including an optical signal conversion board are provided on the equipment side of both communication paths as base points 230 of the respective communication paths. In the STN, in addition to the optical signal conversion board 231, an analog input board (AI) 232, an analog output board (AO) 233, a digital input board (DI) 234, and a digital output board (DO) 235 (collectively referred to as these) Input / output board, input only for input, output board for only output). In the three-base configuration, each base has an A system and a B system, so that there are a total of six base units 230. One communication path 140 and one interface unit 240 are connected to one base unit 230. The base units 230 of the A system and the B system at the same base are connected to the same interface unit 240. The base unit 230 and the interface unit 240 are connected via the above four types of input / output boards. These base units 230 can periodically collect input signals of the analog input board 232 and the digital input board 234, and transmit the input signals to the communication path 140. The output signal received from the communication path 140 is 3 Pieces When they have been collected, one of them can be selected according to a predetermined decision rule and output to the analog output board 233 and the digital output board 235. As the optical signal conversion board 231 of the base unit 230, the same one as the optical signal conversion board 211 of the coupling unit 210 can be used.
[0022]
The interface unit 240 constituted by the interface units (IFU1, IFU2, IFU3) is connected to input / output devices (not shown) of various devices. The interface unit 240 can read the input of the input / output device and transfer it to the respective base units 230 of the A system and the B system. Further, either one of the output signals from the A-system and B-system base units 230 can be selected and output to the input / output device. In the interface unit 240, an analog input interface board (AI) 241, an analog output interface board (AO) 242, a digital input interface board (DI) 243, and a digital output interface board (DO) 244 (collectively referred to as input / output Interface board, input interface board for input only, and output interface board for output only).
[0023]
Here, if the features of the input / output system shown in FIGS. 1 and 2 are summarized,
(1) The triple control device (control panel side 120) and the plant side (device side 110 having input / output devices such as sensors and actuators) are connected by a redundant optical transmission path (A-system and B-system communication path 140). The connection reduces instrumentation costs for wires and the like, and also ensures reliability.
[0024]
(2) Each module (substrate) is provided with a self-diagnosis function to enable quick abnormality detection and alarm output.
[0025]
(3) Triple (or duplex) or unification can be selected according to the importance of the signal, and the system can be flexibly constructed.
[0026]
(4) The input / output interface from the main CPU of the control device is simplified by adopting a VME bus dual port memory system.
[0027]
The characteristics of the individual substrates are as follows.
[0028]
(1) VME bus communication board (R-BUS board) 221
A VME rack is provided in the control panel, and the VME bus communication board 221 is used by being inserted into the VME rack. The main CPU is inserted into the same VME rack, and the VME bus communication board 221 can exchange data (input / output signals) with the main CPU. For redundant communication, two VME bus communication boards 221 for A system and for B system are used. A single VMEbus communication board 221 can be configured at three locations. The interface between the VME bus communication board 221 and the main CPU is a dual port memory as viewed from the main CPU, and the data written in this memory is transmitted to the device as an output signal. The data of the input signal transmitted from the device is set in the memory. The main CPU reads the data of the input signal from the memory and uses it for the control operation.
[0029]
(2) Optical signal conversion substrates 211 and 231
It is arranged on each of the control panel side and the device side, converts data received from the VME bus communication board (control panel side) 221 or the input / output board (device side) into an optical signal and transmits it to the other party. At the time of transmission, transmission arbitration for defining the transmission order of the substrates to be transmitted is performed. Also, the data received as an optical signal is converted into an electric signal and passed to a VME bus communication board or an input / output board.
[0030]
(3) Input / output board
The input / output board includes an analog input board 232, an analog output board 233, a digital input board 234, and a digital output board 235. Each input / output board is provided with a CPU. An analog input board 232 has an A / D converter, an analog output board 233 has a D / A converter, a digital input board 234 has an input buffer for inputting a binary state, and a digital output board 235 has a binary output board. An output register for control output is provided. The input / output board performs input / output with the input / output device via the input / output interface board and exchanges with the optical signal conversion board.
[0031]
Next, the flow of input / output signals will be described.
[0032]
First, the flow of input / output signals between the three control modules (triple control devices) and the input / output board at the base will be described. As shown in FIG. 3, in the A system (the same applies to the B system), the input signals from the analog input board (AI) 232 and the digital input board (DI) 234 are broadcast to control modules (GCU-1, -GCU). 2, -3) is transmitted to 220. On the other hand, among the output signals of the control modules (GCU-1, -2, -3) 220, the analog output value (digital value for analog output) is transmitted to the designated analog output board (AO) 233. The input signal is a broadcast communication, but the output signal is a communication specifying a destination address. In the analog output board (AO) 233, since three analog output values from each control module are prepared, these are selected according to a predetermined decision rule (voting rule). The voting rules are as shown in Table 1.
[0033]
[Table 1]

[0034]
In the case of an analog value, an intermediate value is used when three data are received, and a value on the fail safe side is used when two data are received. In the case of a digital value, a value based on majority decision is adopted when three data are received, and a value on the fail safe side is adopted when two data are received. In any case, the data is used when one data is received, and the previous value is used when there is no received data. However, when one or less data is received, the output according to this determination rule is as shown in Table 1. However, in the reception check, it is determined that the data reception is abnormal, and as a result, the output may not be performed.
[0035]
Next, the flow of the input signal by the duplex communication will be described. As shown in FIG. 4, the states and values of the input / output devices are input to the input / output boards of the A-system and the B-system, for example, the analog input board (AI) 232 via the input interface board. Is transmitted to the VME bus communication board 221 of the control module via the communication path of. The CPU board 222 reads the input signals of the A system and the B system from each dual port memory (DPM) as an input process, and adopts one of the input signals according to the selection rule of Table 2.
[0036]
[Table 2]

[0037]
In Table 2, normal / abnormal is based on the result of the reception check and the self-diagnosis. Although the details will be described later, the reception check result indicates whether the input signal has been correctly received, and the self-diagnosis result indicates whether each of the boards from the input / output board to the VME bus communication board 221 is operating properly. As can be seen from Table 2, the input signal of the normal communication system among the input signals of the A system and the B system is adopted, but when both are normal, the A system has priority.
[0038]
Next, a flow of an output signal by the duplex communication will be described. As shown in FIG. 5, the same output signal is passed from the CPU board 222 of the control module to the A-system and B-system VME bus communication boards 221, and the output signals are input / output boards, for example, via respective communication paths. The signal is transmitted to the analog output board (AO) 233 and further transmitted to the output interface board. At this time, a selection signal is output from the input / output board to the output interface board in addition to the output signal. The selection signal takes two values, normal / abnormal, and the value is based on the result of the reception check and the self-diagnosis. The reception check result indicates whether the output signal has been correctly received, and the self-diagnosis result indicates whether the optical signal conversion board and the input / output board are operating properly. The input / output interface board selects one of the output signals according to the selection rule shown in Table 3 and outputs it to the input / output device.
[0039]
[Table 3]

[0040]
As can be seen from Table 3, the input signal of the normal communication system among the input signals of the A system and the B system is adopted, but when both are normal, the A system has priority.
[0041]
The reception check is performed by the optical signal conversion boards at the coupling part and the base part sandwiching the communication path, and time monitoring, that is, monitoring whether data of input / output signals are received within a predetermined time from each other and redundancy checking are performed. is there. The time monitoring will be described together with the details of the self-diagnosis. A known CRC check is used for the redundancy check. Checksum checks are also used.
[0042]
Next, details of self-diagnosis, time monitoring, and self-calibration will be described.
[0043]
VME bus communication board (CPU operation check)
As shown in FIG. 6, the VME bus communication board 221 periodically checks the operation of the CPU. That is, a reset pulse is output at a period of, for example, 10 msec from a control program executed by the CPU 2211 on the VME bus communication board, and the watchdog timer 2212 is reset. When the reset pulse is not output, the watchdog timer 2212 times out in 15 msec, and an abnormal status is output to the VME bus 223. This abnormal status is read by the CPU board 222 in the same VME rack and output to the DO board 224. The DO board 224 turns on the slot LED 225 on the VME rack insertion side and turns on the module abnormality lamp 1211 on the front door of the control panel 121. Since three CPUs 2211 are mounted on the VME bus communication board 221, three watchdog timers 2212 are also provided, and the logical sum of the outputs of the three becomes an abnormal status.
[0044]
I / O board (CPU operation check)
As shown in FIG. 7, a CPU 2301 is mounted on each input / output board. A watchdog timer 2302 is provided for the CPU 2301 as well. The abnormal status of each input / output board is once passed to the digital input board 234, transmitted from the digital input board to the VME bus communication board 221 via the optical signal conversion boards 231 and 211 and the communication path, and further controlled via the VME bus 223. The notification is sent to the CPU board 222 of the module. An event message is transmitted from the CPU board 222 to the operation consoles 133 and 134.
[0045]
Analog input board
As shown in FIG. 8, the analog input board 232 is provided with an A / D converter (ADC) 2321. The A / D converter 2321 can read a reference level in addition to the analog input from the input / output device. The reference level is such that the reference voltage 10v in the analog input board is equally divided by the ladder resistance circuit 2322, and the voltage at each division point can be switched and input by the analog switch 2323 as the reference voltage. Here, the reference voltage is 10, 8, 6, 4, 2v. Since the −2 operation unit and the × 1.25 operation unit are inserted after the analog switch 2323, 10, 7.5, 5, 2.5, and 0 v are input to the A / D converter 2321. A fixed digital reference value is prepared in the CPU 2324 for the digital value of the reference level thus read, and it is determined whether or not the difference between the two is within a predetermined allowable range. Here, the comparison result of each level is logically ORed and becomes an abnormal status. This abnormal status is once passed to the digital input board 234, transmitted from the digital input board 234 to the VME bus communication board 221 via the optical signal conversion boards 231 and 211 and the communication path, and further transmitted to the CPU of the control module via the VME bus 223. The substrate 222 is notified. An event message is transmitted from the CPU board 222 to the operation consoles 133 and 134.
[0046]
Analog output board
As shown in FIG. 9, a plurality of D / A converters 2331 are provided on the analog output board 233. An A / D converter 2332 for a loopback test is provided, which can switch and read these D / A converter outputs. The CPU 2333 reads the output of the D / A converter 2331 by the A / D converter 2332, and determines whether the difference between the output digital value and the read digital value is within a predetermined allowable range. The abnormal status is once passed to the digital input board 234, transmitted from the digital input board 234 to the VME bus communication board 221 via the optical signal conversion board and the communication path, and further notified to the CPU board 222 of the control module via the VME bus. You. An event message is transmitted from the CPU board 222 to the operation consoles 133 and 134.
[0047]
Digital input board
As shown in FIG. 10, the digital input board 234 is provided with an input buffer 2341 for binary state input. In this input line, short-circuit transistors 2342 and 2343 are provided on the voltage side and the ground side, respectively. The CPU 2344 forcibly turns on and off all state inputs during the period of the input from the input / output device. If the forcible state value read at this timing is not as forcibly determined to be abnormal. The abnormal status is passed to a digital input board (own board or a separate board) 234, transmitted from the digital input board 234 to a VME bus communication board 221 via an optical signal conversion board and a communication path, and further transmitted to a control module via a VME bus. Is notified to the CPU board 222. An event message is transmitted from the CPU board 222 to the operation consoles 133 and 134.
[0048]
Digital output board
As shown in FIG. 11, the digital output board 235 is provided with an output register 2351 for binary control output. The output of the output register 2351 can be read by looping back. The CPU 2352 determines that there is an abnormality if the comparison between the output binary control output and the content read by looping back does not match. The abnormal status is once passed to the digital input board 234, transmitted from the digital input board 234 to the VME bus communication board 221 via the optical signal conversion board and the communication path, and further notified to the CPU board 222 of the control module via the VME bus. You. An event message is transmitted from the CPU board 222 to the operation consoles 133 and 134.
[0049]
7 to 11, the abnormal status of each input / output board is once passed to the digital input board 234, and this abnormal status becomes a selection signal together with the reception check result as a self-diagnosis result. Is output. As described above, the self-diagnosis result is used in each of the interface unit 240 and the control panel 120. In addition, since the self-diagnosis is performed between input / output cycles in each input / output board, there is no delay in the input / output time due to the self-diagnosis.
[0050]
VME bus communication board (Reception time monitoring)
As shown in FIG. 12, the VME bus communication board 221 is provided with a reception overtime monitoring circuit 2213. The reception overtime monitoring circuit 2213 sets a time limit of 200 msec for a transmission cycle of 20 msec from the device side, and if there is no reception within this time limit, sets up an abnormal status in the dual port memory 2214 and reports this abnormal status to the same VME rack. The CPU board 222 inside reads out and outputs it to the DO board 224. The DO board 224 may turn on the communication abnormality lamp 1212 of the control panel front door. Also, an alarm message is transmitted from the CPU board 222 to the operation consoles 133 and 144.
[0051]
Optical signal conversion board (Reception time monitoring)
As shown in FIG. 13, the optical signal conversion boards 211 and 231 are provided with reception overtime monitoring circuits 2001 and 2002. The reception overtime monitoring circuit is provided on each of the electric signal side and the optical signal. The deadline is set in advance by jumpers of the jumper terminal arrays 2003 and 2004. If there is no next reception within this time period after receiving once, an abnormal status is started, and this abnormal status is passed to the digital input board in the control module 220 or the digital input board in the base unit 230. The CPU board reads the input of the digital input board and sends an event message to the operation console.
[0052]
Digital output board (Reception time monitoring)
As shown in FIG. 14, the transmission error detection logic 2353 is incorporated in the digital output board 235. The transmission error detection logic 2353 Pieces Each of the output signals from the control modules has a time limit set by parameters, and if there is no next reception within this time limit, the Control module Is a transmission error and one or more Control module LED lights if transmission is abnormal. Control module If is a transmission error, an abnormal status is issued. The abnormal status is once passed to the digital input board 234, transmitted from the digital input board 234 to the VME bus communication board 221 via the optical signal conversion board and the communication path, and further notified to the CPU board 222 of the control module via the VME bus. You. An event message is transmitted from the CPU board 222 to the operation console. If there is only one control module, Control module If is a transmission error, immediately issue an error status.
[0053]
Analog input board (analog input self-calibration)
As described above with reference to FIG. 8, the A / D converter 2321 of the analog input board 232 can read a plurality of reference levels (reference voltages, 10, 8, 6, 4, 2v) by the ladder resistance circuit 2322. I have. The self-calibration of the analog input is performed using the A / D conversion values of these reference levels. For this purpose, a reference voltage by the ladder resistance circuit 2322 is strictly measured by a measuring device in advance (for example, when an analog input board is manufactured), and an ideal A / D conversion value for the strictly measured value is calculated. The data is written in an electrically erasable read-only memory (EEPROM, not shown). The CPU 2324 creates polygonal line data based on the ideal A / D conversion value for the strictly measured value, and applies the A / D conversion value of the analog input from the input / output device to the polygonal line data for correction.
[0054]
Analog output board (analog output self-calibration)
Similar to the self-calibration of the analog input board, a polygonal line approximation using data at a plurality of points is used. For this purpose, in the analog output board 233 shown in FIG. 9, the digital value is output from the minimum value to the maximum value in increments of the minimum resolution and output to the D / A converter 2331, and a loopback test is performed for each value. A / D converter 2332 converts the output current into a plurality of values, for example, 4, 8, 12, 16, 20 mA, when the output current becomes a plurality of values. Is written in the EEPROM as a calibration value. The plurality of calibration values form polygonal line data for obtaining a digital value necessary to obtain an analog value actually output to the input / output device. The CPU 2334 applies a digital value to be output to the polygonal line data to make a correction, and outputs the corrected digital value to the D / A converter 2331.
[0055]
Next, single / multiple selection will be described.
[0056]
15 to 18 show various forms of single / multiple selection. First, the one in FIG. Pieces Of control modules (GCU-1, GCU-2, GCU-3) and a single control module (DAU). The analog output board 233 and the digital output board 235 of the base unit 230 are provided with four receiving units 310 corresponding to the control modules, and the data of the output signal is transmitted from each control module 220 to the receiving unit 310. ing. Each reception unit 310 includes a CRC check unit 311, a timeout monitoring unit 312, and a reception memory 313. A voting switch 321 and a single / multiple selection switch 322 are provided on the extraction side of the reception memory 313. A status including an input signal and the like is transmitted from the base unit 230 to each control module 220 by broadcast communication. The voting switch 321 expresses, as an element, a function which is selectively adopted in accordance with the decision rule as described above. Each control module includes a timeout monitoring unit 411 and a memory 412 for a plurality of channels. According to this, 3 Pieces The triple output from the control module (GCU-1, GCU-2, GCU-3) is selected for each channel by the voting switch 321 of the base unit 230, and then passed to the single / multiple selection switch 322. . On the other hand, the single system output is passed to the single / multiple selection switch 322 as it is. The selection between the triple system and the single system is made in the single / multiple selection switch 322 for each channel. The output thus selected is output to the analog output interface board (AO) 242 and the digital output interface board (DO) 244.
[0057]
In FIG. 16, the output signal from a single control module (DAU) is not used, and instead, one of the output signals from three control modules (GCU-1, GCU-2, GCU-3) is used. Is used for single system output. Therefore, the reception memory for a single control module (DAU) is not used, and one of the extraction sides of the reception memory 313 for the triple system output is connected to the single / multiple selection switch 322. A status including an input signal and the like is transmitted from the base unit 230 to each control module 220 by broadcast communication.
[0058]
In FIG. 17, only output signals from a single control module (DAU) are used. Therefore, the memory for triple output (the shaded portion) is not used. The single / multiple selection switch 322 is fixed. The single output from the control module (DAU) is output to the analog output interface board (AO) 242 and the digital output interface board (DO) 244 as they are. A status including an input signal and the like is transmitted from the base unit 230 to each control module 220 by broadcast communication.
[0059]
The one shown in FIG. 18 uses two single system outputs. A single control module (DAU, GCU) is provided for each, and the base unit 230 is provided with two corresponding receiving units 310. The selection of the double single system is performed by the selection switch 322 for each channel. A status including an input signal and the like is transmitted from the base unit 230 to each control module 220 by broadcast communication.
[0060]
15 to 18 can be arbitrarily selected. In this way, multiplexing can be set variously in consideration of the importance of input and output.
[0061]
【The invention's effect】
The present invention exhibits the following excellent effects.
[0062]
(1) Since only two communication paths are required for the multiplexed control system, the cost of the communication path can be reduced.
[0063]
(2) Since the input signal is selected on the control panel side using the results of the reception check and the self-diagnosis, fault-tolerance can be ensured.
[0064]
(3) Since the output signal is selected on the device side using the result of the reception check or the self-diagnosis, the fault tolerant property can be ensured.
[0065]
(4) The self-diagnosis of the CPU and the input / output elements is performed on each of the input / output boards, so that the abnormality can be accurately detected and the reliability of the input / output signal selected based on the self-diagnosis result can be improved. Can be.
[0066]
(5) Since the self-calibration and self-diagnosis of the analog input are performed based on a plurality of reference levels, a precise measured value is obtained and the measured value is highly reliable.
[0067]
(6) Since the reception check is performed by monitoring the reception time and checking the data redundancy, the reliability of communication can be improved.
[0068]
(7) Since selection can be made between single and multiple, arbitrary multiplexing according to the importance of input / output signals becomes possible.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gas turbine power plant showing one embodiment of the present invention.
FIG. 2 is a basic configuration diagram of a flexible high-speed multiplexing remote input / output system in the plant of FIG.
FIG. 3 is a diagram showing a flow of input / output signals between a triple control device of the present invention and a base.
FIG. 4 is a diagram showing a flow of an input signal by the duplex communication of the present invention.
FIG. 5 is a diagram showing a flow of an output signal by the duplex communication of the present invention.
FIG. 6 is a circuit configuration diagram for confirming a CPU operation in the VME bus communication board of the present invention.
FIG. 7 is a circuit configuration diagram for checking CPU operation on each input / output board of the present invention.
FIG. 8 is a circuit configuration diagram for A / D conversion input of a reference level in the analog input board of the present invention.
FIG. 9 is a circuit configuration diagram for a loopback test on the analog output board of the present invention.
FIG. 10 is a circuit configuration diagram for inputting a forced state value in the digital input board of the present invention.
FIG. 11 is a circuit configuration diagram for a loopback test on the digital output board of the present invention.
FIG. 12 is a circuit configuration diagram for monitoring reception time in the VME bus communication board of the present invention.
FIG. 13 is a circuit configuration diagram for monitoring a reception time in the optical signal conversion board of the present invention.
FIG. 14 is a circuit configuration diagram for monitoring reception time in the digital output board of the present invention.
FIG. 15 is a diagram showing the flow of input / output signals according to one mode of single / multiple selection of the present invention.
FIG. 16 is a diagram illustrating the flow of input / output signals according to one mode of single / multiple selection of the present invention.
FIG. 17 is a diagram showing the flow of input / output signals according to one mode of single / multiple selection of the present invention.
FIG. 18 is a diagram showing the flow of input / output signals according to one mode of single / multiple selection of the present invention.
[Explanation of symbols]
110 Equipment side (plant system)
120 Control panel side (control system)
140 communication channel
210 Joint
220 control module
230 bases
240 interface

Claims (9)

Sensors installed in the plant equipment, to input and output devices such as actuators, in a multiplexing system in a control panel provided with a plurality number of control modules in parallel to control the device by its input and output signals, and a device control panel Two communication paths are provided between the two communication paths, and the control panel side of both system communication paths is provided with a coupling unit for sequentially transmitting output signals of all control modules and distributing received input signals to each control module. On the equipment side of both communication paths, there is provided a base unit for sequentially transmitting input signals and selecting one of output signals received from all control modules in accordance with a predetermined decision rule. One of the input signals distributed from the coupling section of the communication path is selected, and the input / output device reads the input and receives the input at the base of both communication paths. Flexible high-speed multiplexed remote output system being characterized in that to connect the interface unit to output the alternative either of the output signals from the base portion of both strains channel with passing. 2. The flexible high-speed multiplexing remote input / output system according to claim 1, wherein the base unit adopts the alternative according to the decision rule and using the result of the reception check at the base unit. 3. The flexible high-speed communication method according to claim 1, wherein the selection of the input signal performed by the control module is performed in accordance with a predetermined decision rule using a result of a self-diagnosis performed by a reception check and a base performed by each coupling unit. Multiplexed remote I / O system. 4. The flexible high-speed communication system according to claim 1, wherein the selection of the output signal performed by the interface unit is performed in accordance with a predetermined decision rule using a result of a self-diagnosis performed by the reception check and the self-diagnosis performed by each base unit. Multiplexed remote I / O system. The base unit includes an analog input board including a CPU and an A / D converter, an analog output board including a CPU and a D / A converter, and an input buffer for inputting a binary state. It has a digital input board and a digital output board equipped with a CPU and an output register for binary control output. For each board, periodically check the operation of the CPU, and perform A / D conversion input of a reference level, D / A The self-diagnosis is performed by A / D conversion reading of a converter output, input of a forced state value or reading of an output register, and the self-diagnosis result is transmitted to the interface unit and the control module. 4. The flexible high-speed multiplexing remote input / output system according to any one of 4 above. The base unit has a plurality of reference levels for analog input, and performs self-calibration and self-diagnosis of the analog input using A / D conversion values of these reference levels. Item 6. A flexible high-speed multiplexed remote input / output system according to any one of Items 1 to 5. The base unit is characterized in that a digital calibration value at which an analog output becomes a predetermined value of a plurality of stages by D / A conversion is measured in advance, and a digital value is corrected by these calibration values before D / A conversion. 7. A remote high-speed multiplexed remote input / output system according to claim 1. 8. The communication system according to claim 1, wherein the coupling unit and the base unit sandwiching the communication path monitor reception of input / output signal data within a predetermined period of time and perform a reception check by a redundancy check of the data. The flexible high-speed multiplexed remote input / output system according to any of the above. 9. The switch according to claim 1, wherein the base unit includes a single / multiple selection switch for selecting whether to use only one fixed control module or one of a plurality of control modules for output signals. The flexible high-speed multiplexed remote input / output system according to any of the above.

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