WO1996008098A1 - Process for data transmission between data processing stations or devices - Google Patents

Process for data transmission between data processing stations or devices Download PDF

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Publication number
WO1996008098A1
WO1996008098A1 PCT/AT1995/000167 AT9500167W WO9608098A1 WO 1996008098 A1 WO1996008098 A1 WO 1996008098A1 AT 9500167 W AT9500167 W AT 9500167W WO 9608098 A1 WO9608098 A1 WO 9608098A1
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WIPO (PCT)
Prior art keywords
station
fault
network
stations
broadcast
Prior art date
Application number
PCT/AT1995/000167
Other languages
German (de)
French (fr)
Inventor
Norbert Bock
Original Assignee
Elin Energieanwendung Gmbh
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Publication date
Application filed by Elin Energieanwendung Gmbh filed Critical Elin Energieanwendung Gmbh
Publication of WO1996008098A1 publication Critical patent/WO1996008098A1/en

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H04L12/40169—Flexible bus arrangements
    • H04L12/40176—Flexible bus arrangements involving redundancy
    • H04L12/40189—Flexible bus arrangements involving redundancy by using a plurality of bus systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H04L12/407—Bus networks with decentralised control
    • H04L12/417—Bus networks with decentralised control with deterministic access, e.g. token passing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/40—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H04L2012/4026—Bus for use in automation systems

Definitions

  • the invention relates to a method for data transmission between information processing stations or devices, e.g. Programmable logic controllers, host computers or operating devices for automation technology, which are connected to each other via a double (redundant) network with serial or parallel buses, and where the data is transferred using the token-passing method.
  • information processing stations or devices e.g. Programmable logic controllers, host computers or operating devices for automation technology
  • Bus systems have the advantage that all stations are connected in parallel to the data carrier (bus line), which means that when individual stations are switched off there is no breakdown of the network. In the case of bus systems, the information is also transmitted faster than in the case of ring systems.
  • the "token” is a defined bit sequence that is passed on from one station, each of which has a unique identification number in the network, to the next. Each station forwards the “token” to the station with the next higher identification number in the network. Since the number of identification numbers to be assigned is limited, the station with the lowest number receives the "token” from the station with the highest number, as a result of which a logical ring is formed in the network. The “token” remains with the station during transmission. This ensures that there is no data collision on the bus.
  • a property of the token passing method is that stations can be switched on or off at any time. However, a reconfiguration is necessary to maintain the logical token ring.
  • a new station When a new station is switched on or closed If an existing network is connected, it does not get a token because at the beginning no identification number is entered as a new number at any station. After the token timeout has expired, the new station sends out a continuous signal and thus interrupts the current communication. All stations now begin to count down from the highest identification number until they have reached their own station number. If a station has reached its own number, it now tries to pass the token on to the station with the next higher one. If this station does not exist, an attempt is made to pass the token on to the station with the number increased by two. This is repeated until an existing station is reached.
  • the attempt is made to send the token to the station with the lowest possible number. If the token transfer to a second station was successful, their identification number is saved as a new number. The second station now tries to pass on the token to the station with the next higher number, this is increased by one until the next station is reached. When all stations have entered the number of their successor stations, the reconfiguration is complete.
  • the transmission authorization (token) is passed on from one station to the next both on the active and on the passive bus.
  • the object of the invention is now to create a method for a double-executed or redundant network, with which one of the two buses gradually becomes active for all stations in the event of a fault.
  • the object is achieved by the invention, which is characterized in that all stations work according to a constant synchronized time cycle which is divided into three phases, which run in the order of synchronization phase, broadcast phase and message phase, with the beginning and end of each phase in all stations Network is known, and that the type of data telegram that is released by each individual station for transmission is determined by the phase that is currently relevant, and that each station cyclically and independently of each other independently of each other for functionality or errors (Fault) is monitored, and that each error in the entire network is assigned a unique error weight as an even number, and that each station has either the conditions observed itself or those reported by another station with the highest error weight on the one for the sending station currently active bus the other stations in the network in the broadcast phase, in which each station sends a data telegram to all stations one after the other, and that each station
  • the functional, interference-free network is assigned the error weight "0".
  • a further development of the invention is that those stations in the network that are not capable of redundancy are assigned the highest error weight. Since this is the largest possible error, the next broadcast phase immediately switches from the redundant network to a single network.
  • the station which is the first to receive transmission authorization in the broadcast phase becomes the broadcast master in this time cycle and only from this at If the next send authorization is received, the broadcast end telegram is sent on both buses, and therefore only a single broadcast end telegram occurs in the functional, interference-free network on the active and passive bus during a cycle, and that if more than one broadcast end occurs An error is derived on the telegram on one of the two or on both buses. This measure can be used to determine which of the two buses is defective and the bus that is in Ordnimg also immediately becomes active.
  • the fault weight is reduced in constant steps until the weight is either "0" or, in the event of a multiple fault, a pending fault with a lower weight until then determines which bus the active and which becomes the passive. Since the error weight in the individual stations does not immediately take on the lowest value after an error has been corrected, subsequent errors with a lower weight are partially ignored, depending on the time of occurrence.
  • FIG. 1 shows the structure of a redundant network and FIG. 2 shows the time cycle in the fault-free case on the passive bus.
  • the network 1 shows four stations 1, 2, 3, 4 connected to a redundant network.
  • This network consists of two parallel or serial buses 5, 6, one of which is always the active and the other the passive for each station 1, 2, 3, 4.
  • Each station 1, 2, 3, 4 has two network controllers 7, 8, one of which is connected to bus 5 and the second to bus 6.
  • the network controllers 7, 8 can be implemented in hardware or software.
  • each station 1, 2, 3, 4 sends a data telegram to all stations 1, 2, 3, 4.
  • all stations 1, 2, 3, 4 connected to the redundant network receive the transmission authorization (token) and send a released data telegram on their currently active bus 5 or 6.
  • the duration of the broadcast phase depends on the number of stations 1, 2, 3, 4 connected to the redundant network.
  • the broadcast phase is followed by message phase 11, in which each station 1, 2, 3, 4 sends a data telegram on the bus currently active for it 5 or 6 to a certain other station 1, 2, 3, 4, as long as it receives the transmission authorization.
  • This phase 11 is followed by the synchronization phase 13, 14 with the first 13 and the second synchronization telegram 14, which are likewise sent again on both buses 5, 6.
  • the first synchronization telegram 13 is sent by the station that is the first to get the token in this phase 13, 14. All stations 1, 2, 3, 4 on the network are time-synchronized with this telegram 13.
  • the second synchronization telegram 14 is sent by the station which subsequently receives the token and is ignored in all stations 1, 2, 3, 4.
  • the downward direction of the time cycle 9 is indicated by an arrow in this figure.
  • the duration of a time cycle is in the range of a few 100 ms.

Abstract

In a data transmission process of the token passing type between data processing stations (1, 2, 3, 4) connected to a redundant network (5, 6) for automation technology, all the stations operate on a constant synchronised time cycle (9) which is divided into three phases running in the order synchronisation phase (13, 14), broadcast phase (10) and message phase (11). Each of the two buses (5, 6) is cyclically per se and mutually independently monitored by each station (1, 2, 3, 4) for reliability or faults (interference), whereby an unambiguous even-numbered fault weighting is allocated to each fault throughout the network. Each station (1, 2, 3, 4) informs the other stations (1, 2, 3, 4) in the network of the statuses observed either itself or announced by another station (1, 2, 3, 4) with the highest fault weighting to the active bus (5, 6) for the transmitting station in the broadcast phase (10). Each station (1, 2, 3, 4) immediately decides which of the two buses (5, 6) becomes active and which becomes passive on the basis of the fault with the highest weighting observed by itself or announced by another station (1, 2, 3, 4). In the event of one fault, therefore, there is an automatic switchover to that bus (5, 6) that is in order and which becomes the active one. Once the fault has been corrected, e.g. a line break on one of the two buses (5, 6), redundant operation is automatically resumed.

Description

VERFAHREN ZUR DATENÜBERTRAGUNG ZWISCHEN INFORMATIONSVERARBEΓΓENDEN STATIONEN BZW. GERATEN METHOD FOR TRANSMITTING DATA BETWEEN INFORMATION PROCESSING STATIONS OR. DEVICES
BESCHREIBUNGDESCRIPTION
Die Erfindung betrifft ein Verfahren zur Datenübertragung zwischen informations¬ verarbeitenden Stationen bzw. Geräten, z.B. speicherprogrammierbaren Steuerungen, Leitrechnern oder Bediengeräten für die Automatisierungstechnik, die über ein doppelt ausgeführtes (redundantes) Netzwerk mit seriellen oder parallelen Bussen miteinander verbunden sind, und wobei die Datenübertragung nach dem Token- passing- Verfahren erfolgt.The invention relates to a method for data transmission between information processing stations or devices, e.g. Programmable logic controllers, host computers or operating devices for automation technology, which are connected to each other via a double (redundant) network with serial or parallel buses, and where the data is transferred using the token-passing method.
Netzwerke die zur digitalen Datenkommunikation zwischen einzelnen Stationen ver¬ wendet werden, sind entweder als Bus- oder Ringsysteme aufgebaut. Bussysteme haben den Vorteil, daß alle Stationen parallel am Datenträger (Busleitung) ange¬ schlossen sind, wodurch bei einer Abschaltung von einzelnen Stationen kein Zusam¬ menbruch des Netzwerkes erfolgt. Bei Bussystemen erfolgt außerdem die Informa¬ tionsübertragung auch schneller als bei Ringsystemen.Networks that are used for digital data communication between individual stations are constructed either as bus or ring systems. Bus systems have the advantage that all stations are connected in parallel to the data carrier (bus line), which means that when individual stations are switched off there is no breakdown of the network. In the case of bus systems, the information is also transmitted faster than in the case of ring systems.
Der "Token" ist eine definierte Bitfolge, die von einer Station, von denen jede eine im Netzwerk eindeutige Identifikationsnummer besitzt, zur nächsten weitergegeben wird. Jede Station gibt den "Token" an die Station mit der nächsthöheren Identifikations¬ nummer im Netzwerk weiter. Da die Anzahl der zu vergebenden Identifikations¬ nummern begrenzt ist, erhält die Station mit der niederigsten Nummer den "Token" von der Station mit der höchsten Nummer, wodurch im Netzwerk ein logischer Ring gebildet wird. Der "Token" bleibt während des Sendens bei der Station. Dadurch ist gewährleistet, daß es zu keiner Datenkollision am Bus kommt.The "token" is a defined bit sequence that is passed on from one station, each of which has a unique identification number in the network, to the next. Each station forwards the "token" to the station with the next higher identification number in the network. Since the number of identification numbers to be assigned is limited, the station with the lowest number receives the "token" from the station with the highest number, as a result of which a logical ring is formed in the network. The "token" remains with the station during transmission. This ensures that there is no data collision on the bus.
Eine Eigenschaft des Token-passing- Verfahrens ist, daß man jederzeit Stationen weg- oder zuschalten kann. Damit jedoch der logische Tokenring aufrecht erhalten bleibt, ist eine Rekonfiguration notwendig. Wenn eine neue Station eingeschaltet, bzw. zu einem bestehenden Netzwerk zugeschaltet wird, bekommt diese keinen Token, weil zu Beginn bei keiner Station ihre Identifikationsnummer als neue Nummer eingetragen ist. Nach Ablauf des Token-Timeouts sendet die neue Station ein Dauersignal aus und unterbricht somit die momentane Kommunikation. Alle Stationen beginnen nun von der höchsten Identifikationsnummer abwärts zu zählen, bis sie ihre eigene Stations¬ nummer erreicht haben. Wenn eine Station ihre eigene Nummer erreicht hat, so versucht sie nun den Token an die Station mit der nächsthöheren weiterzugeben. Gibt es diese Station nicht, so wird versucht den Token an die Station mit der um zwei erhöhten Nummer weiterzugeben. Dies wird solange wiederholt, bis eine vorhandene Station erreicht ist. Dabei wird nach dem Versuch den Token an die Station mit der höchstmöglichen Nummer zu übergeben, versucht den Token an jene mit der niederigstmöglichen Nummer zu senden. Wenn die Tokenweitergabe an eine zweite Station erfolgreich war, wird deren Identifikationsnummer als neue Nummer gespeichert. Die zweite Station versucht nun ihrerseits den Token an die Station mit der nächsthöheren Nummer weiterzugeben, dies wird jeweils um eins erhöht, solange wiederholt, bis die Nachfolgestation erreicht ist. Wenn alle Stationen die Nummer ihrer Nachfolgestationen eingetragen haben, ist die Rekonfiguration abgeschlossen.A property of the token passing method is that stations can be switched on or off at any time. However, a reconfiguration is necessary to maintain the logical token ring. When a new station is switched on or closed If an existing network is connected, it does not get a token because at the beginning no identification number is entered as a new number at any station. After the token timeout has expired, the new station sends out a continuous signal and thus interrupts the current communication. All stations now begin to count down from the highest identification number until they have reached their own station number. If a station has reached its own number, it now tries to pass the token on to the station with the next higher one. If this station does not exist, an attempt is made to pass the token on to the station with the number increased by two. This is repeated until an existing station is reached. After the attempt to transfer the token to the station with the highest possible number, the attempt is made to send the token to the station with the lowest possible number. If the token transfer to a second station was successful, their identification number is saved as a new number. The second station now tries to pass on the token to the station with the next higher number, this is increased by one until the next station is reached. When all stations have entered the number of their successor stations, the reconfiguration is complete.
Wird der Token an eine Station weitergegeben, die ausgefallen oder vom Netzwerk weggeschaltet ist, geht er verloren. Die momentane Kommunikation ist somit unter¬ brochen und es beginnt die Rekonfiguration nach dem selben Verfahren wie oben beschrieben.If the token is passed on to a station that has failed or has been disconnected from the network, it is lost. The current communication is thus interrupted and the reconfiguration begins using the same method as described above.
Bei einem redundanten Netzwerk wird die Sendeberechtigung (Token) sowohl auf dem aktiven als auch auf dem passiven Bus von einer Station zur nächsten weiter¬ gegeben.In the case of a redundant network, the transmission authorization (token) is passed on from one station to the next both on the active and on the passive bus.
Die Aufgabe der Erfindung besteht nun darin, ein Verfahren für ein doppelt aus¬ geführtes bzw. redundantes Netzwerk zu schaffen, mit dem im Fehlerfall sukzessive immer einer der beiden Busse für alle Stationen zum aktiven wird. Die Aufgabe wird durch die Erfindung gelöst, welche dadurch gekennzeichnet ist, daß alle Stationen nach einem konstanten synchronisierten Zeitzyklus arbeiten, der in drei Phasen geteilt ist, die in der Reihenfolge Synchronisierphase, Broadcastphase und Messagephase ablaufen, wobei Anfang und Ende jeder Phase allen Stationen im Netzwerk bekannt ist, und daß von der zum aktuellen Zeitpunkt wiiicsamen Phase die Art des Datentelegrammes bestimmt wird, welches von jeder einzelnen Station zum Senden freigegeben wird, und daß von jeder Station zyklisch jeder der beiden Busse für sich und unabhängig voneinander auf Funktionsfähigkeit bzw. Fehler (Störung) überwacht wird, und daß jedem Fehler im gesamten Netzwerk ein eindeutiges Fehler- gewicht als geradzahliger Wert zugeordnet ist, und daß jede Station die entweder selbst beobachteten Zustände oder von einer anderen Station gemeldeten Zustände mit dem höchsten Fehlergewicht auf den für die sendende Station gerade aktiven Bus den anderen Stationen im Netzwerk in der Broadcastphase, in der nacheinander jede Station ein Datentelegramm an alle Stationen sendet, mitteilt, und daß jede Station auf Basis jenes selbst beobachteten oder von einer anderen Station gemeldeten Fehlers mit dem höchsten Fehlergewicht sofort entscheidet, welcher der beiden Busse zum aktiven und welcher zum passiven wird. Im Ein-Fehler-Fall erfolgt somit eine auto¬ matische Umschaltung auf jenen Bus, d.h. dieser wird zum aktiven, der in Ordnung ist. Nach der Behebung des Fehlers, z.B. einer Leitungsunterbrechung auf einem der beiden Busse, wird automatisch wieder in den Redundanzbetrieb umgeschaltet.The object of the invention is now to create a method for a double-executed or redundant network, with which one of the two buses gradually becomes active for all stations in the event of a fault. The object is achieved by the invention, which is characterized in that all stations work according to a constant synchronized time cycle which is divided into three phases, which run in the order of synchronization phase, broadcast phase and message phase, with the beginning and end of each phase in all stations Network is known, and that the type of data telegram that is released by each individual station for transmission is determined by the phase that is currently relevant, and that each station cyclically and independently of each other independently of each other for functionality or errors (Fault) is monitored, and that each error in the entire network is assigned a unique error weight as an even number, and that each station has either the conditions observed itself or those reported by another station with the highest error weight on the one for the sending station currently active bus the other stations in the network in the broadcast phase, in which each station sends a data telegram to all stations one after the other, and that each station with the highest error weight, based on the fault that it has observed itself or reported by another station, immediately decides which of the two buses to go to active and which becomes passive. In the case of a single fault, there is therefore an automatic switchover to that bus, ie this bus becomes the active bus which is in order. After the error has been rectified, e.g. a line break on one of the two buses, the system automatically switches back to redundancy mode.
Nach einer Ausgestaltung wird dem funktionsfähigen, störungsfreien Netzwerk das Fehlergewicht "0" zugeordnet wird.According to one embodiment, the functional, interference-free network is assigned the error weight "0".
Eine Weiterbildung der Erfindung liegt darin, daß jenen Stationen im Netzwerk, die nicht redundanzfähig sind das höchste Fehlergewicht zugeordnet wird. Da dies der größtmögliche Fehlerfall ist, wird sofort in der nächsten Broadcastphase vom redundanten Netzwerk auf ein Single-Netzwerk umgeschaltet.A further development of the invention is that those stations in the network that are not capable of redundancy are assigned the highest error weight. Since this is the largest possible error, the next broadcast phase immediately switches from the redundant network to a single network.
Von Vorteil ist, daß jene Station die in der Broadcastphase als erste die Sendeberech¬ tigung erhält in diesem Zeitzyklus zum Broadcastmaster wird und nur von dieser bei Erhalt der nächsten Sendeberechtigung das Broadcastende-Telegramm auf beiden Bussen gesendet wird, und daß daher im funktionsfähigen, störungsfreien Netzwerk am aktiven und am passiven Bus während eines Zyklus nur je ein einziges Broadcastende-Telegramm auftritt, und daß bei Auftreten von mehr als einem Broadcastende-Telegramm auf einem der beiden oder auf beiden Bussen ein Fehler abgeleitet wird. Durch diese Maßnahme kann rückgeschlossen werden, welcher der beiden Busse defekt ist und es wird weiters auch sofort jener Bus der in Ordnimg ist zum aktiven.It is advantageous that the station which is the first to receive transmission authorization in the broadcast phase becomes the broadcast master in this time cycle and only from this at If the next send authorization is received, the broadcast end telegram is sent on both buses, and therefore only a single broadcast end telegram occurs in the functional, interference-free network on the active and passive bus during a cycle, and that if more than one broadcast end occurs An error is derived on the telegram on one of the two or on both buses. This measure can be used to determine which of the two buses is defective and the bus that is in Ordnimg also immediately becomes active.
Letztlich ist von Vorteil, daß, sofeme ein einmal erkannter Fehler behoben ist, das Fehlergewicht solange in konstanten Schritten vermindert wird, bis das Gewicht entweder "0" ist oder bis im Mehrfehlerfall ein anstehender Fehler mit bis zu diesem Zeitpunkt niederigerem Gewicht bestimmt, welcher Bus der aktive und welcher der passive wird. Da nach der Behebung eines Fehlers das Fehlergewicht in den einzelnen Stationen nicht sofort den niedrigsten Wert einnimmt, werden Folgefehler mit niedrigerem Gewicht zum Teil, abhängig vom Zeitpunkt des Auftretens, ignoriert.Ultimately, it is an advantage that, once a fault has been identified, the fault weight is reduced in constant steps until the weight is either "0" or, in the event of a multiple fault, a pending fault with a lower weight until then determines which bus the active and which becomes the passive. Since the error weight in the individual stations does not immediately take on the lowest value after an error has been corrected, subsequent errors with a lower weight are partially ignored, depending on the time of occurrence.
Die Erfindung wird nun anhand der Zeichnungen noch näher erläutert.The invention will now be explained in more detail with reference to the drawings.
Die Fig. 1 zeigt den Aufbau eines redundanten Netzwerkes und in Fig. 2 ist der Zeit¬ zyklus im fehlerfreien Fall am passiven Bus dargestellt.1 shows the structure of a redundant network and FIG. 2 shows the time cycle in the fault-free case on the passive bus.
Bei Fig. 1 sind vier an einem redundanten Netzwerk angeschlossene Stationen 1, 2, 3, 4 ersichtlich. Dieses Netzwerk besteht aus zwei parallelen oder seriellen Bussen 5, 6, von denen für jede Station 1, 2, 3, 4 immer einer der aktive und der andere der passive ist. Jede Station 1, 2, 3, 4 weist zwei Netzwerk-Controller 7, 8 auf, von denen einer an Bus 5 und der zweite an Bus 6 angeschlossen ist. Die Netzwerk-Controller 7, 8 können hard- oder softwaremäßig realisiert werden.1 shows four stations 1, 2, 3, 4 connected to a redundant network. This network consists of two parallel or serial buses 5, 6, one of which is always the active and the other the passive for each station 1, 2, 3, 4. Each station 1, 2, 3, 4 has two network controllers 7, 8, one of which is connected to bus 5 and the second to bus 6. The network controllers 7, 8 can be implemented in hardware or software.
Bei Fig. 2 ist der Beginn der Broadcastphase 10 bei der Zeit t = 0 festgelegt. In dieser Phase 10 sendet jede Station 1, 2, 3, 4 ein Datentelegramm an alle Stationen 1, 2, 3, 4. In dieser Broadcastphase 10 erhalten alle am redundanten Netzwerk ange¬ schlossenen Stationen 1, 2, 3, 4 die Sendeberechtigung (Token) und schicken ein frei¬ gegebenes Datentelegramm auf ihrem gerade aktiven Bus 5 oder 6 ab. Das Broadcastende-Telegramm 12 sendet jene Station auf beiden Bussen 5, 6, die in dieser Phase 10 als erste, also zum Zeitpunkt t = 0 die Sendeberechtigung erhalten hat. Die Dauer der Broadcastphase ist abhängig von der Anzahl der am redundanten Netzwerk angeschlossenen Stationen 1, 2, 3, 4. Der Broadcastphase folgt die Messagephase 11, in der jede Station 1, 2, 3, 4 ein Dateπtelegramm auf dem gerade für sie aktiven Bus 5 oder 6 an eine bestimmte andere Station 1, 2, 3, 4, sofeme sie die Sendeberechtigung erhält, senden kann. An diese Phase 11 folgt die Synchronisierphase 13, 14 mit dem ersten 13 und dem zweiten Synchronisiertelegramm 14 die ebenfalls wieder auf beiden Bussen 5, 6 gesendet werden. Das erste Synchronisiertelegramm 13 wird von jener Station gesendet, die als erste in dieser Phase 13, 14 in den Besitz des Token kommt. Mit diesem Telegramm 13 werden alle Stationen 1, 2, 3, 4 am Netzwerk zeitsynchro- nisiert. Das zweite Synchronisiertelegramm 14 wird von der Station die anschließend den Token erhält gesendet und wird in allen Stationen 1, 2, 3, 4 ignoriert.2, the start of the broadcast phase 10 is determined at the time t = 0. In this phase 10, each station 1, 2, 3, 4 sends a data telegram to all stations 1, 2, 3, 4. In this broadcast phase 10, all stations 1, 2, 3, 4 connected to the redundant network receive the transmission authorization (token) and send a released data telegram on their currently active bus 5 or 6. The end of broadcast telegram 12 sends the station on both buses 5, 6 which in this phase 10 was the first to receive the transmission authorization, ie at time t = 0. The duration of the broadcast phase depends on the number of stations 1, 2, 3, 4 connected to the redundant network. The broadcast phase is followed by message phase 11, in which each station 1, 2, 3, 4 sends a data telegram on the bus currently active for it 5 or 6 to a certain other station 1, 2, 3, 4, as long as it receives the transmission authorization. This phase 11 is followed by the synchronization phase 13, 14 with the first 13 and the second synchronization telegram 14, which are likewise sent again on both buses 5, 6. The first synchronization telegram 13 is sent by the station that is the first to get the token in this phase 13, 14. All stations 1, 2, 3, 4 on the network are time-synchronized with this telegram 13. The second synchronization telegram 14 is sent by the station which subsequently receives the token and is ignored in all stations 1, 2, 3, 4.
Die Abiaufrichtung des Zeitzyklus 9 ist in dieser Fig. mit einem Pfeil angedeutet.The downward direction of the time cycle 9 is indicated by an arrow in this figure.
Die Dauer eines Zeitzyklus liegt im Bereich von einigen 100ms.The duration of a time cycle is in the range of a few 100 ms.
Anhand der Fig. 1 wird der erfindungsgemäße Verfahrensablauf bei einem Ein-Fehler- Fall nun noch erläutert. Es wird angenommen, daß ein fehlerfreies redundantes Netzwerk vorliegt und daher alle Stationen 1, 2, 3, 4 den Bus 5 als ihren aktiven "A" festgelegt haben. Bei Stelle 15 auf Bus 5 ist plötzlich ein Leitungsbruch eingetreten. Im nächstfolgenden Zeitzyklus 9 wird zufallig die Station 1 zum Broadcast-Master der auch das Broadcastende-Tele¬ gramm 12 auf beiden Bussen S, 6 sendet. Die Stationen 3 und 4 empfangen nun auf dem Bus 5 kein Broadcastende-Telegramm 12 mehr. Sie erhöhen nun ihr Fehler- gewicht von derzeit "0" auf den für diesen Fehler festgelegten Wert und schalten gleichzeitig auf den Bus 6 als ihren aktiven um. Empfangen nun diese beiden Stationen 3, 4 in der Broadcastphase 10 Datentelegramme in denen ein geringeres Fehlergewicht aufscheint, werden diese ignoriert. Die beiden Stationen 3, 4 senden in der Broadcastphase 10 ihr derzeitiges Fehlergewicht auf ihrem aktiven Bus 6 an alle anderen Stationen. Nach Behebung des Leitungsbruches werden die Stationen 3, 4 ihr Fehlergewicht wieder auf "0" reduzieren und auf Bus S als ihren aktiven umschalten. The process sequence according to the invention in the case of a one-fault case will now be explained with reference to FIG. 1. It is assumed that there is an error-free redundant network and therefore all stations 1, 2, 3, 4 have defined bus 5 as their active "A". At point 15 on bus 5, a line break suddenly occurred. In the next following time cycle 9, station 1 becomes the broadcast master, which also sends the broadcast end telegram 12 on both buses S, 6. Stations 3 and 4 no longer receive an end of broadcast telegram 12 on bus 5. You now increase your error weight from the current "0" to the value specified for this error and at the same time switch to bus 6 as your active one. Now receive these two Stations 3, 4 in the broadcast phase 10 data telegrams in which a lower error weight appears, these are ignored. In the broadcast phase 10, the two stations 3, 4 send their current error weight on their active bus 6 to all other stations. After eliminating the line break, stations 3, 4 will reduce their error weight to "0" again and switch to bus S as their active one.

Claims

PATENTANSPRÜCHE PATENT CLAIMS
1. Verfahren zur Datenübertragung zwischen informationsverarbeitenden Stationen bzw. Geräten, z.B. speicherprogrammierbaren Steuerungen, Leitrechnern oder Bediengeräten für die Automatisierungstechnik, die über ein doppelt ausgeführtes1. Method for data transmission between information processing stations or devices, e.g. Programmable logic controllers, host computers or operator devices for automation technology that have a double execution
(redundantes) Netzwerk mit seriellen oder parallelen Bussen miteinander ver¬ bunden sind, und wobei die Datenübertragung nach dem Token-passing- Verfahren erfolgt, dadurch gekennzeichnet, daß alle Stationen nach einem konstanten synchronisierten Zeitzyklus arbeiten, der in drei Phasen geteilt ist, die in der Reihenfolge Synchronisierphase, Broadcastphase und Messagephase ablaufen, wobei Anfang und Ende jeder Phase allen Stationen im Netzwerk bekannt ist, und daß von der zum aktuellen Zeitpunkt wirksamen Phase die Art des Datentele- grammes bestimmt wird, welches von jeder einzelnen Station zum Senden frei¬ gegeben wird, und daß von jeder Station zyklisch jeder der beiden Busse für sich und unabhängig voneinander auf Funktionsfähigkeit bzw. Fehler (Störung) über¬ wacht wird, und daß jedem Fehler im gesamten Netzwerk ein eindeutiges Fehler¬ gewicht als geradzahliger Wert zugeordnet ist, und daß jede Station die entweder selbst beobachteten Zustände oder von einer anderen Station gemeldeten Zustände mit dem höchsten Fehlergewicht auf den für die sendende Station gerade aktiven Bus den anderen Stationen im Netzwerk in der Broadcastphase, in der nachein¬ ander jede Station ein Datentelegramm an alle Stationen sendet, mitteilt, und daß jede Station auf Basis jenes selbst beobachteten oder von einer anderen Station gemeldeten Fehlers mit dem höchsten Fehlergewicht sofort entscheidet, welcher der beiden Busse zum aktiven und welcher zum passiven wird.(Redundant) network with serial or parallel buses are connected to each other, and the data transmission takes place according to the token passing method, characterized in that all stations work according to a constant synchronized time cycle, which is divided into three phases, which are divided into three phases the sequence of the synchronization phase, broadcast phase and message phase take place, the beginning and end of each phase being known to all stations in the network, and that the type of data telegram which is released by each individual station for transmission is determined by the phase which is currently active and that each station cyclically monitors each of the two buses independently and independently of one another for functionality or error (fault), and that each error in the entire network is assigned a unique error weight as an even value, and that each station either the conditions observed by itself or from another States reported to the other stations in the network in the broadcast phase, in which each station sends a data telegram to all stations, and states that each station is observing itself on the basis of the conditions reported with the highest error weight on the bus currently active for the transmitting station or an error reported by another station with the highest error weight immediately decides which of the two buses will be active and which will be passive.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß dem funktionsfähigen, störungsfreien Netzwerk das Fehlergewicht "0" zugeordnet wird.2. The method according to claim 1, characterized in that the functional, interference-free network, the error weight "0" is assigned.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß jenen Stationen im Netzwerk, die nicht redundanzfähig sind das höchste Fehlergewicht zugeordnet wird. 3. The method according to claim 1 or 2, characterized in that those stations in the network that are not capable of redundancy are assigned the highest error weight.
4. Verfahren nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß jene Station die in der Broadcastphase als erste die Sendeberechtigung erhält in diesem Zeitzyklus zum Broadcastmaster wird und nur von dieser bei Erhalt der nächsten Sendeberechtigung das Broadcastende-Telegramm auf beiden Bussen gesendet wird, und daß daher im funktionsfähigen, störungsfreien Netzwerk am aktiven und am passiven Bus während eines Zyklus nur je ein einziges Broadcastende-Tele¬ gramm auftritt, und daß bei Auftreten von mehr als einem Broadcastende-Tele¬ gramm auf einem der beiden oder auf beiden Bussen ein Fehler abgeleitet wird.4. The method according to any one of claims 1 to 3, characterized in that that station which receives the broadcast authorization in the broadcast phase as the broadcast master becomes the broadcast master in this time cycle and only when the next broadcast authorization is received the broadcast end telegram is sent on both buses , and therefore only a single broadcast end telegram occurs in the functional, interference-free network on the active and passive bus during a cycle, and that when more than one broadcast end telegram occurs on one of the two or on both buses an error is derived.
S. Verfahren nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß, sofeme ein einmal erkannter Fehler behoben ist, das Fehlergewicht solange in konstanten Schritten vermindert wird, bis das Gewicht entweder "0" ist oder bis imS. Method according to one of claims 1 to 4, characterized in that, as soon as a fault which has been recognized is remedied, the weight of the fault is reduced in constant steps until the weight is either "0" or until
Mehrfehlerfall ein anstehender Fehler mit bis zu diesem Zeitpunkt niederigerem Gewicht bestimmt, welcher Bus der aktive und welcher der passive wird. In the event of a multiple fault, a pending fault with a lower weight up to this point determines which bus will be the active and which the passive.
PCT/AT1995/000167 1994-09-02 1995-08-17 Process for data transmission between data processing stations or devices WO1996008098A1 (en)

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WO1999014989A1 (en) * 1997-09-18 1999-03-25 Siemens Aktiengesellschaft Control device for airport lighting systems
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EP0878981A2 (en) * 1997-05-16 1998-11-18 Siemens Aktiengesellschaft Current stabiliser
EP0878981A3 (en) * 1997-05-16 2000-08-23 Siemens Aktiengesellschaft Current stabiliser
WO1999014989A1 (en) * 1997-09-18 1999-03-25 Siemens Aktiengesellschaft Control device for airport lighting systems
WO2001063850A1 (en) * 2000-02-25 2001-08-30 Honeywell International Inc. Multiple network fault tolerance via redundant network control
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WO2001084313A2 (en) * 2000-05-02 2001-11-08 Sun Microsystems, Inc. Method and system for achieving high availability in a networked computer system
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