EP1543652A1

EP1543652A1 - Communication system with users and diagnostic units

Info

Publication number: EP1543652A1
Application number: EP03750340A
Authority: EP
Inventors: Michael Franke; Karl-Heinz Krause; Michael KÖSTNER
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2002-09-24
Filing date: 2003-09-11
Publication date: 2005-06-22
Also published as: WO2004030275A1; DE10244427A1; US20050229040A1

Abstract

The invention relates to a distributed communication system (1), in particular a real-time-critical, cyclical real-time Ethernet system, provided with automation technology with several users, each of which is provided with at least one diagnostic unit (7, 8, 15) for the diagnosis and display of data concerning the data exchange between users and also provided with a further user, embodied as central diagnostic station (13), whereby said central diagnostic station (13) carries out a central diagnosis of the whole communication system (1) by configuration of the diagnostic units (7, 8, 15) in the users and calling up and analysing the displayed diagnostic data by means of the diagnostic units (7, 8, 15) in the users.

Description

description

COMMUNICATION SYSTEM WITH PARTICIPANT AND DIAGNOSTIC UNIT

The invention relates to a communication system with participants with a diagnostic unit.

A communication system is understood to be a system with at least two participants which are connected to one another via a data network for the purpose of mutual exchange of data or the mutual transmission of data.

Participants are, for example, central automation devices, programming, configuration or operating devices, peripheral devices such as Input / output modules, drives, actuators, sensors, programmable logic controllers (PLC) or other control units, computers or machines that exchange electronic data with other participants, in particular process data from other participants. Participants are also called network nodes or nodes.

In the following, control units are understood to mean regulator or control units of any kind, but also, for example, coupling units (so-called switches) and / or switch controllers. For example, switched communication systems, such as switched Ethernet, industrial Ethernet, but in particular isochronous real-time Ethernet, are used as data networks.

In today's switched communication systems, the communication relationships between the participants are directed by the network components via dedicated network segments. This relieves the burden on segments that are not involved in communication. A central unit, via which all communication is handled, for example a repeater on a communication bus, no longer exists, where the possibility of performing a central diagnosis of a communication system is also lost.

So far, the diagnosis of such communication systems has been carried out by decentrally connected analyzers. The analyzer is connected to the corresponding network components and records the data traffic there. The evaluation is done by manually evaluating the recording log. For a complete recording, the analyzer may possibly be connected to several points of the communication system at the same time, since not all communication relationships necessarily pass through a single node with regard to their path in the communication system.

The invention is therefore based on the object of specifying an improved communication system which enables central diagnosis of the communication system.

This object is achieved by a communication system with at least a first and a second subscriber, which are connected to one another by means of at least one communication link, the subscribers having at least one diagnostic unit, the diagnostic unit for diagnosing data that facilitate the data exchange of at least one communication relationship between at least two Affect participants is provided.

According to a preferred embodiment of the invention, the diagnostic unit has at least one evaluation unit which is provided for evaluating the diagnosed data.

According to a preferred embodiment of the invention, the diagnostic unit has at least one buffer memory which is provided for the temporary storage of the diagnosed data. The data which may have been evaluated and buffered in this way can very easily be stored in a memory of the are transferred to the corresponding subscriber, since the diagnostic unit is integrated in the corresponding subscriber and is thus directly connected to and has access to the other components of the subscriber, for example a computer and thus in particular also to a memory of the subscriber. The data stored there can then be called up and evaluated at any time, for example by another participant in the communication system.

According to a preferred embodiment of the invention, the communication system is a switched communication system of an Ethernet type or a real-time Ethernet type. It is particularly advantageous if this is a cyclically operating communication system, in which the communication between the participants takes place in transmission cycles. In such a switchable communication system, at least one coupling unit is connected between two subscribers and is connected to both subscribers. However, each coupling unit can also be connected to more than two participants. Each participant is connected to at least one coupling unit, but not directly to another participant. A coupling unit is also understood to be a switch. Such a high-performance data network generally consists of a large number of distributed nodes, in particular also a large number of distributed switches. These switches can be separate network nodes, but can also be integrated in one node. For real-time applications, when the telegrams pass through the communication system, the arrival time or send time of the telegrams at the switches or the other participants is very important. As a result, the observation of telegrams as well as the chronological tracking of telegrams in the communication system is particularly important, for example for tracing when error events occur. Such recording mechanisms are, for example, statistics about the message or communication load in a time unit or at certain times, the number of received or sent telegrams per time unit, error statistics, for example how many faulty telegrams occurred in which time unit, but also, for example, the amount of throughput data.

Some such recording mechanisms exist in a switch. However, these cannot be configured in such a way that only selected, required data is recorded. In contrast, the entire data traffic flowing through the corresponding subscriber or switch is recorded, the required data having to be filtered out manually from the corresponding protocol lists of the switch or subscriber concerned. However, especially for real-time communication, the individual recording of events with regard to individual telegrams, that is to say specific individual transactions, is very important. Such a recording must be given a corresponding time stamp so that the desired events can be traced or understood. This allows conclusions to be drawn regarding the optimization of the data traffic of the communication system, in particular in real-time communication.

According to a further preferred embodiment of the invention, the diagnostic unit of the participants is provided to provide the diagnosed and / or evaluated and / or recorded data on the communication relationship between at least two participants with a unique identifier. For cyclic operation of the communication system, the unique identifier consists of at least two parts, one part for identifying the cycle identifier and the other part for identifying the communication relationship between the respective participants. The cycle identifier can be, for example, the number of the current communication cycle, while the communication relationship can be identified, for example, by a so-called frame ID of a data telegram. Of course other unique identifier alternatives are also possible. Selected data records can thus be identified very easily and can be uniquely assigned to specific participants, in particular specific communication relationships or communication connections between two or more participants.

According to a further preferred embodiment of the invention, the diagnostic unit of the participants is provided for diagnosis and / or for evaluation and / or for recording various events that occur during data exchange between at least two participants. The diagnosis and / or the evaluation and / or the recording of error events is particularly advantageous. In addition, it is particularly advantageous that the diagnostic unit of the participants is provided for selecting the type and number of events to be diagnosed and / or evaluated and / or recorded, in particular error events, and the associated data volume. In addition, it is also very advantageous that the

Diagnostic unit for port-specific and / or for communication-specific diagnosis and / or evaluation and / or recording of the data traffic by a subscriber is provided.

A subscriber's diagnostic unit can be configured, for example, such that a selection of events or individual events that relate to one or more communication links between two or more subscribers can be recorded individually. In particular, those events are diagnosed, evaluated and recorded that relate to transactions of individual individual telegrams. For example, the time of arrival of certain individual telegrams can be recognized and recorded. Other events are ignored accordingly. Such events are, for example, "time of receipt of data packet X," errors in data packet Y, etc. Furthermore the number of events itself can also be configured, for example in such a way that a corresponding message is output after a certain number of one or more diagnosed events. This also applies analogously to the associated data volume. Of course, the diagnosis, evaluation and / or recording of any other event is also conceivable, in particular also the entire data traffic in a subscriber in a predefinable time unit, or also the data traffic of any selected port of a subscriber.

For the analysis of error situations or for the tracing of errors that have occurred, it is particularly advantageous that the diagnostic units can be configured such that selected error events are diagnosed, evaluated and recorded. For this purpose, for example, several different communication connections or relationships between several participants as well as individual communication connections or individual telegrams can be considered. Error events are e.g. Incorrect time of arrival of telegrams, number of telegrams with incorrect content, but also, for example, the incorrect arrival of individual, specific telegrams, e.g. There is no telegram X. This is of particular importance for real-time-critical data or in communication systems with real-time applications, since error events such as e.g. the absence of telegrams or the late arrival of telegrams, the real-time capability is no longer guaranteed. An analysis of such error events in particular is therefore extremely important. The diagnosis, evaluation and storage of error events is of course also port-specific and communication-specific.

Such a targeted diagnosis of, for example, selected communication relationships can significantly reduce the amount of information or data to be recorded. the. This also simplifies the evaluation of the data accordingly. In addition, the selection of the data to be diagnosed and / or recorded can be very quickly and easily adapted to any changed boundary conditions by appropriately configuring the affected diagnostic units. For example, due to an error situation that has occurred, it is possible very quickly and easily to record events that are correlated with a specific desired telegram in addition to the events that are already to be recorded. Likewise, the amount of data to be recorded can be reduced if the recording of certain events no longer appears to be necessary.

According to a particularly preferred embodiment of the invention, at least one further subscriber is provided, which is designed as a central diagnostic station, the central diagnostic station having means for selecting the data to be diagnosed and / or evaluated and / or recorded and means for appropriately configuring the respective diagnostic units the remaining participant has. Since in a communication system according to the invention, at least one diagnostic unit is integrated in each network node, which has means for diagnosing and / or evaluating and / or recording data which belong to, in particular, individual communication relationships or connections between at least two participants, and the participants in one Such a central diagnosis station according to the invention can naturally communicate with one another in such a way that the communication system can communicate with all participants and thus with all diagnostic units and transmit appropriate information and / or instructions to the diagnostic units of the respective participants. In particular when using a communication system according to the invention in the real-time application area, in which the communication traffic within the communication system of all participants is planned accordingly in order to incorporate the real-time conditions. hold, the identifier of the data and all network nodes that are traversed by them are known. When planning such real-time data traffic in advance, a so-called project planning tool is generally used in the automation area, which is in particular also part of the central diagnostic station or includes it. The selection of the events to be recorded or diagnosed, in particular error events, can then take place, for example, by manual identification by a user, but also automatically by the configuration tool, and thus the central diagnostic station itself. On the basis of the relevant events selected in this way, the central diagnostic station determines or knows the identifier of the data and all nodes through which it passes. The central diagnostic station generates the corresponding configuration information on the basis of this information and sends it to all affected subscribers or network nodes who configure the integrated diagnostic units of the network nodes or communication participants accordingly in order to receive the data to be diagnosed and recorded.

It is also conceivable that the configuration tool is not integrated in the participant who is trained as a central diagnostic station. In this case, the corresponding configuration information must be transferred from the configuration tool to the central diagnostic station. This is conceivable, for example, by data exchange using an infrared interface or radio link, but data transfer via diskettes is also possible. Other usual transmission paths are of course also possible. Another alternative to configuring the individual diagnostic units of the participants is that the central diagnostic station uses broadcast mechanisms to notify all nodes of the network, for example which communication connections or telegrams are to be monitored. Each network node then uses its current configuration to check whether it is the transmitter, Receiver or pass-through of affected telegrams is and sets its diagnostic units accordingly.

The implementation of such a central diagnosis station means that there is no need to distribute several analyzers in the network, which means both cost and time savings. Furthermore, the topology of a network no longer has to be changed, which is otherwise always necessary if an additional analyzer has to be looped into a section. Furthermore, the corresponding diagnostic information is always available, regardless of the central diagnostic station, which makes it possible to subsequently analyze errors. If the configuration is selected using broadcast mechanisms, the path of a telegram through a network does not have to be known either, since the corresponding network nodes themselves perform a check of the diagnostic data to be monitored and possibly recorded. Such a targeted diagnosis of communication relationships can reduce the amount of information to be recorded. The evaluation of the data is thus significantly simplified. Furthermore, the requirements for the resources of the network nodes are significantly reduced. The execution of such a central diagnosis station is also possible in the form that the central diagnosis station is designed to be mobile, ie that the central diagnosis station can connect to the communication network at any time and dial in accordingly and does not necessarily have to be permanently connected to the communication system , Any remote access to the corresponding diagnostic information is therefore very easy and flexible. Appropriate designs with a notebook are conceivable and possible. Dialing in via a suitable radio connection is of course also possible.

According to a further preferred embodiment of the invention, the central diagnostic station is for retrieving and / or evaluating the information that the respective diagnostic units of the rest of the provided data recorded participants of the communication system. The diagnosed data are monitored in the individual network nodes by the diagnostic units integrated in the respective subscriber, possibly stored in a so-called intermediate buffer and then transferred to a further memory of the subscriber. From there, they can be called up very easily from the central diagnostic station and evaluated online within the central diagnostic station. In addition, the central diagnostic station can also be decoupled from the communication system after the diagnostic data has been called up from the individual diagnostic units. A corresponding evaluation of the information retrieved can take place offline on the device itself. If new or different diagnostic information is required as a result of these evaluations, the diagnostic units of the individual network nodes can be immediately reconfigured in both cases in order to immediately deliver other diagnostic data.

The communication system can advantageously itself represent an automation system, but it can also be used or used in automation systems, in particular in packaging machines, presses, plastic injection machines, textile machines, printing machines, machine tools, robots, handling systems, wood processing machines, glass processing machines, ceramic processing machines and lifting equipment.

It is also particularly advantageous if a subscriber in an inventive communication system is an automation device. Such a subscriber can in particular be a network node with an integrated coupling unit, it being particularly advantageous if the integrated coupling unit is a real-time Ethernet switch. The invention is described and explained in more detail below on the basis of the exemplary embodiments illustrated in the figures.

Show it:

1 shows a block diagram of an embodiment of a communication system according to the invention and

2 shows an example of diagnostic data

FIG. 1 shows a block diagram of an exemplary embodiment of a communication system 1 according to the invention. The communication system 1 shown represents, for example, a distributed, real-time capable automation system. The present communication system 1 is also a switched communication network, which is a real-time Ethernet system. The present communication system 1 is a cyclic system i.e. data transmission takes place in one or more transmission cycles.

The communication system shown consists of several subscribers, who can be both sender and receiver at the same time. In particular, the communication system 1 consists of a first subscriber 2, a second subscriber 3, and further subscribers 17, 18, 19, 20, 21, which can be designed, for example, as computers and / or automation devices, for example as drives. Each of the participants in the communication system 1 has an associated coupling unit, which is also referred to below as a switch. The coupling units are used for sending and / or receiving and / or forwarding the data to be transmitted. The coupling units or switches shown are preferably designed as real-time Ethernet switches. For reasons of clarity, only the switches 5, 6 of the first and the second subscriber and the switch 16 of the subscriber 20 have been designated. For all participants is the associated switch integrated in the respective participant as an example. A subscriber is designed as a central diagnostic station 13. The central diagnostic station 13 can, for example, also be integrated in a control computer of an automation system. The connection of the participants to one another is ensured by communication connections, of which only the connection between participant 2 and participant 3 is designated by the communication connections 4a, 4b, 4c and 4d for the sake of clarity. The participants are also referred to as network nodes.

Each of the switches has several ports, which for the sake of clarity have not been shown and have not been labeled. The communication connections, which each end in or on a switch, symbolize the different ports. According to the invention, each of the switches present has at least one diagnostic unit, of which only the diagnostic unit 7 of the first participant 2, the diagnostic unit 8 of the second participant 3 and the diagnostic unit 15 of the participant 20 have been designated for the sake of clarity. Such a diagnostic unit is provided for diagnosing data relating to the data exchange between network participants, for example between the first participant 2 and the second participant 3.

The diagnostic units can be configured, in particular by the central diagnostic station 13, so that only a predeterminable selection of events, in particular error events, which relate to the communication connections between participants, for example transactions of individual telegrams, can be individually diagnosed, evaluated and recorded. Other events are ignored accordingly. Such events to be selected are, for example, “time of reception of data packet X in subscriber 2 ^λ ,“ incorrect time of arrival of telegram Y in subscriber 3, etc. Of course, the diagnosis, evaluation and / or recording of any other event is nisse also conceivable, in particular the recording of the entire data traffic of, for example, subscriber 3 in a predeterminable time unit. Such a targeted diagnosis of communication relationships can reduce the amount of information to be recorded. The evaluation of the data is thus significantly simplified. Furthermore, the requirements for the resources of the network nodes are significantly reduced.

In the case of the network subscribers, several diagnostic units per subscriber were sometimes shown, but were not identified. To show that the diagnostic units integrated in the respective network participants or switches diagnose, evaluate or record port-specific data, one diagnostic unit was shown for each incoming and outgoing communication connection. The respective diagnostic unit is preferably designed such that only a single diagnostic unit is integrated in the corresponding subscriber or switch, it being possible for each port of the corresponding switch or network subscriber to be diagnosed separately. The corresponding network participants can, however, also have several diagnostic units if required.

Each of the diagnostic units is equipped with at least one evaluation unit, which is provided for evaluating the diagnosed data, and at least one buffer memory. For the sake of clarity, the corresponding evaluation units 9 and 10 and the buffer memories 11 and 12 were only shown for the diagnostic units 7 and 8 of the subscribers 2 and 3, respectively. The representation and designation of the evaluation units or buffer memory in the other diagnostic units has been omitted for reasons of clarity. The buffer memories 11, 12 are provided for the temporary storage of the diagnosed data, for example the data which are sent from the first subscriber 2 to the second subscriber 3 or vice versa. Before the intermediate storage, the diagnosed data may be stored in the corresponding data Evaluation units 9, 10 evaluated. The temporarily stored data are then transferred, for example, to a memory of the corresponding subscriber, from where they are called up at any time, in particular also later, for example by the central diagnostic station 13 and evaluated centrally. The diagnostic information is therefore permanently available in the participants' memories, which means that error analysis is also possible afterwards.

The central diagnostic station 13 is connected via the communication link 14, for example, to the switch 16 integrated in the subscriber 20, more precisely to the diagnostic unit 15 integrated in the switch 16, and in this way a subscriber to the communication network 1. The central diagnostic station 13 can act as a network subscriber to all other subscribers access. In addition, it is designed in such a way that it configures the diagnostic units of the other participants, retrieves and separately evaluates the data of the diagnostic units of the other participants, which, for example, were buffered in the buffer memories or in other memories of the participants themselves or were evaluated, if necessary can, that is, a central diagnosis of the communication system 1 is possible by the central diagnosis station 13. The evaluation of the diagnostic data called up in this way can take place online within the central diagnostic station 13. The central diagnostic station 13 can also be decoupled from the communication system 1 after the diagnostic data has been called up from the individual diagnostic units and the corresponding evaluation can be carried out offline. If new or different diagnostic information is required as a result of these evaluations, the diagnostic units of the individual network nodes can be immediately reconfigured in both cases in order to immediately deliver other diagnostic data.

In particular in the case of a distributed, real-time-critical automation system, as shown here, the communication of all participants with one another is accordingly planned to to comply with the real time conditions. As a result, the identifiers of the data and all network nodes or participants through which they are known are known. When planning such real-time data traffic in advance, a so-called project planning tool is generally used in the automation area, which is preferably part of the central diagnostic station 13. The selection of the events to be recorded or diagnosed, in particular the error events, can be done, for example, by manual identification by a user, but also by automatic selection by the project planning tool, and thus the central diagnostic station 13 itself. Based on the relevant events selected in this way, the central diagnostic station 13 generates the corresponding configuration information and sends it to all affected subscribers or network nodes, for example subscribers 2 or 3, who configure the integrated diagnostic units 5 or 6 in order to obtain the desired diagnostic data.

It is also conceivable that the configuration tool is not integrated in the central diagnostic station 13. In this case, the corresponding configuration information must be transmitted from the configuration tool to the central diagnostic station 13. This is conceivable, for example, by data exchange using an infrared interface or radio link, but data transfer via diskettes is also possible. Other usual transmission paths are of course also possible.

Another alternative to configuring the individual diagnostic units of the subscribers is that the central diagnostic station uses broadcast mechanisms to notify all nodes in the network, for example to monitor the communication between subscribers 2 and 3. Each network node then checks on the basis of its current configuration whether it is the sender, receiver or pass-through of the affected telegrams and adjusts its diagnostic units accordingly. In the- In this case, participants 17, 18 and 19 would be affected as pass-throughs and participants 2, 3 as both sender and receiver. The other participants 20, 21 would not be affected.

The central diagnostic station 13 can also be designed as a mobile station, for example as a notebook, ie the central diagnostic station 13 can connect to any subscriber in the communication network 1 at any time and thus dial into the communication network 1 and not necessarily must be permanently connected to communication system 1. This means that any remote access to the corresponding diagnostic information of the individual network participants is possible very easily, flexibly and centrally, in particular at any later point in time. Dialing in via a suitable radio connection is of course also possible.

The implementation of such a central diagnosis station 13 means that there is no need to distribute a number of analyzers in the network, which means both cost and time savings. Furthermore, the topology of a network no longer has to be changed, which is otherwise always necessary when an additional analyzer has to be looped into a section. If the configuration is selected via broadcast mechanisms, the route of a telegram through a network does not have to be known either, since the corresponding network nodes themselves take over a check of the diagnostic data to be monitored and possibly recorded.

FIG. 2 shows an excerpt from an exemplary representation of diagnostic data in the central diagnostic station 13 in the form of a table 29. In the example shown here, for example, the data traffic between the subscribers 2 and 3 from FIG. 1 should be in any time interval 0.00 to 1.00 Unit of time for any occurrence to be monitored.

The first column 22 of table 29 lists the times at which an event occurred in the relevant time interval. In order to be able to clearly assign the recorded events to a specific communication relationship between, for example, two participants, the diagnostic units of the participants provide the diagnosed or recorded events with a unique identifier according to the invention. For cyclical operation of the exemplary communication system 1 from FIG. 1, the unique identifier consists, for example, of two parts, one part for example the communication cycle and the other part the communication relationship between the participants involved, for example participants 2 and 3, that is to say the transmitter or receiver features. In the second column 23 of table 29, the corresponding communication cycle in which the event occurred is therefore listed for each recorded event. In the third column 24, the sender of the relevant data packet and, at the same time, the associated receiver can be clearly identified by means of a so-called frame ID. In the present example, the exemplary frame ID “234 * can clearly identify, for example, subscriber 2 as the transmitter and subscriber 3 as the receiver of the transmitted data. The fourth column 25 of table 29 finally lists the route of the data packet across all intermediate stations to the receiver, including the respective status of the data packet sent. The fifth column 26 documents the arrival of the data packet at the recipient.

In the present example, two events have occurred in the relevant time interval, which relate to the communication relationship between subscriber 2 as transmitter and subscriber 3 as receiver. The first event is listed in the first line 27 of table 29 and shows that a data ten packet in the communication cycle "01β ^xλ from subscriber 2 via subscriber 17, subscriber 18 and subscriber 19 was sent to subscriber 3 completely correctly and was received by the subscriber at the time" 0.12 ^λΛ . The second exemplary event is listed in the second line 28 of the table 29, and indicates that a data packet in the communication cycle "105 ^λ of subscriber 2 to subscriber 17 has been forwarded properly, but when re-transmitting the data packet on the way to subscriber 18, an error on the Line was present (CRC - cyclical redundancy check; checksum check) so that the data packet could not be received or could only be received incorrectly by subscriber 18 and, as a result, could not reach the correct recipient, subscriber 3.

Such a targeted diagnosis of selected communication relationships can significantly reduce the amount of information or data to be recorded. This also simplifies the evaluation of the data accordingly. In addition, the selection of the data to be diagnosed and / or recorded can be very quickly and easily adapted to any changed boundary conditions by appropriate configuration of the diagnostic units concerned. For example, due to an error situation that has occurred, it is very quickly and easily possible to record events that are correlated with a specific desired telegram in addition to the events that are already to be recorded. Likewise, the amount of data to be recorded can be reduced if the recording of certain events no longer appears to be necessary.

In summary, the invention relates to a distributed communication system 1, in particular a real-time-critical, cyclical real-time Ethernet system in automation technology, with a plurality of subscribers, each of whom has at least one diagnostic unit 7, 8, 15 for diagnosing and recording data which are used for data exchange Concern participants, is equipped, and a further subscriber, which is designed as a central diagnostic station 13, the central diagnostic station 13 providing a central diagnosis of the entire communication system 1 by configuring the diagnostic units 7, 8, 15 of the subscribers and calling up and evaluating the recorded diagnostic data by the diagnostic units 7, 8, 15 of the participants.

Claims

claims

1. Communication system (1) with at least a first (2) and a second subscriber (3), which are connected to one another by means of at least one communication link (4a, 4b, 4c, 4d), the subscribers (2, 3) at least have a diagnostic unit (7, 8), the diagnostic unit (7, 8) being provided for diagnosing data relating to the data exchange of at least one communication relationship between at least two participants (2, 3).

2. Communication system according to claim 1, so that the diagnostic unit (7, 8) has at least one evaluation unit (9, 10) which is provided for evaluating the diagnosed data.

3. Communication system according to one of claims 1 or 2, so that the diagnostic unit (7, 8) has at least one buffer memory (11, 12) which is provided for the intermediate storage of the diagnosed data.

4. Communication system according to one of the preceding claims, so that the communication system (1) is a switched communication system (1) of an Ethernet type or a real-time Ethernet type.

5. Communication system according to one of the preceding claims, so that the communication system (1) is a cyclically operating communication system (1).

β. Communication system according to one of the preceding claims, characterized in that the diagnostic unit (7, 8) of the participants (2, 3) is provided to provide the diagnosed and / or evaluated and / or recorded data on the communication relationship between at least two participants (2, 3) with a unique identifier ,

7. Communication system according to one of the preceding claims, characterized in that the unique identifier for a cyclical operation of the communication system (1) consists of two parts, one part for identifying the cycle identifier and the other part for identifying the communication relationship between the respective participants (2, 3) is provided.

8. Communication system according to one of the preceding claims, characterized in that the diagnostic unit (7, 8) of the participants (2, 3) for diagnosis and / or for evaluation and / or for recording various events which see at least two participants during data exchange (2, 3) occur, is provided.

9. Communication system according to claim 8, characterized in that the diagnostic unit (7, 8) of the participants (2, 3) is provided for selecting the type and number of events to be diagnosed and / or evaluated and / or recorded, and the associated data volume ,

10. Communication system according to one of claims 8 or 9, characterized in that the diagnostic unit (7, 8) of the participants (2, 3) for diagnosis and / or for evaluation and / or for recording error events that occur during data exchange between at least two participants (2, 3) occur, is provided.

11. Communication system according to one of the preceding claims, that the diagnostic unit (7, 8) is provided for port-specific and / or for communication-specific diagnosis and / or evaluation and / or recording of the data traffic by a subscriber (2, 3).

12. Communication system according to one of the preceding claims, characterized in that at least one further participant is provided, which is designed as a central diagnostic station (13), the central diagnostic station (13) means for selecting the to be diagnosed and / or evaluated and / or recorded Has data and means for corresponding configuration of the respective diagnostic units of the other participants (17, 18, 19, 20, 21, 22).

13. Communication system according to claim 12, characterized in that the central diagnostic station (13) for retrieving and / or evaluating the, by the respective diagnostic units of the other participants (17, 18, 19, 20, 21, 22) of the communication system (1) recorded Data is provided.

14. Communication system according to one of the preceding claims, d a d u r c h g e k e n n z e i c h n e t that the communication system (1) is an automation system.

15. Participant (2, 3) in a communication system (1) with at least one diagnostic unit (7, 8), the diagnostic unit (7, 8) for diagnosing data that facilitate the data exchange of at least one communication relationship between at least two participants (2, 3) concern, is provided.

16. Participant according to claim 15, characterized in that the diagnostic unit (7, 8) of the subscriber (2, 3) has at least one evaluation unit (9, 10) which is provided for evaluating the diagnosed data.

17. Participant according to one of claims 15 or 16, ^" characterized in that the diagnostic unit (7, 8) of the participant (2, 3) has at least one buffer memory (11, 12) which is provided for intermediate storage of the diagnosed data.

18. Participant according to one of claims 15 to 17, characterized in that the diagnostic unit (7, 8) of the participant (2, 3) is provided for the diagnosed and / or evaluated and / or recorded data on the communication relationship between at least two participants (2, 3) with a unique identifier.

19. Participant according to one of claims 15 to 18, characterized in that the diagnostic unit (7, 8) of the participant (2, 3) for diagnosis and / or for evaluation and / or for recording various events that occur during data exchange between at least two participants (2, 3) occur, is provided.

20. Participant according to claim 19, characterized in that the diagnostic unit (7, 8) of the participant (2, 3) is provided for selecting the type and number of events to be diagnosed and / or evaluated and / or recorded, and the associated data volume ,

21. Communication system according to one of claims 19 or 20, characterized in that that the diagnostic unit (7, 8) of the participant (2, 3) is provided for diagnosis and / or for evaluation and / or for recording error events which occur during data exchange between at least two participants (2, 3).

22. Participant according to one of claims 15 to 21, characterized in that the diagnostic unit (7, 8) of the participant (2, 3) for port-specific and / or for communication-specific diagnosis and / or evaluation and / or recording of the data traffic by a participant ( 2, 3) is provided.

23. Participant according to one of claims 15 to 22, characterized in that the participant (2, 3) is designed as a central diagnostic station (13), wherein the central diagnostic station (13) means for selecting the to be diagnosed and / or evaluated and / or data to be recorded and means for corresponding configuration of the respective diagnostic units of the other participants (17, 18, 19, 20, 21, 22).

24. Participant according to claim 23, characterized in that the participant (2, 3), which is designed as a central diagnostic station (13), means for retrieving and / or evaluating the, by the respective diagnostic units of the other participants (17, 18, 19th , 20, 21, 22) of the communication system (1) has recorded data.

25. Participant according to one of claims 15 to 24, so that the participant (2, 3, 20) is a network node with an integrated coupling unit (16) and / or an automation device.

26. Participant according to claim 25, characterized in that the integrated coupling unit (16) is a real-time Ethernet

Switch is.