US9270481B2 - Communication system and method for isochronous data transmission in real time - Google Patents

Communication system and method for isochronous data transmission in real time Download PDF

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US9270481B2
US9270481B2 US13/809,195 US201113809195A US9270481B2 US 9270481 B2 US9270481 B2 US 9270481B2 US 201113809195 A US201113809195 A US 201113809195A US 9270481 B2 US9270481 B2 US 9270481B2
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real time
critical data
communication
time
communication device
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US20130195114A1 (en
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Gunnar Lessmann
Carsten Pieper
Sebastian Schriegel
Eugen Breit
Markus Schumacher
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Phoenix Contact GmbH and Co KG
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Phoenix Contact GmbH and Co KG
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Priority claimed from DE201010027167 external-priority patent/DE102010027167B4/de
Priority claimed from DE201010052322 external-priority patent/DE102010052322A1/de
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Assigned to PHOENIX CONTACT GMBH & CO. KG reassignment PHOENIX CONTACT GMBH & CO. KG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BREIT, EUGEN, SCHRIEGEL, SEBASTIAN, PIEPER, CARSTEN, SCHUMACHER, MARKUS, LESSMANN, GUNNAR
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    • 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
    • H04L12/40006—Architecture of a communication node
    • H04L12/40013—Details regarding a bus controller
    • 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
    • H04L12/40143—Bus networks involving priority mechanisms
    • H04L12/4015—Bus networks involving priority mechanisms by scheduling the transmission of messages at the communication node
    • 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]
    • H04L12/46—Interconnection of networks
    • H04L12/4604—LAN interconnection over a backbone network, e.g. Internet, Frame Relay
    • H04L12/462—LAN interconnection over a bridge based backbone
    • H04L12/4625—Single bridge functionality, e.g. connection of two networks over a single bridge
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/50—Queue scheduling
    • H04L47/56—Queue scheduling implementing delay-aware scheduling
    • H04L47/564—Attaching a deadline to packets, e.g. earliest due date first

Definitions

  • the present invention relates to a communication system as well as a method for isochronous transmission of real time-critical data over a real time-controlled Ethernet data network having at least one first communication device with a synchronized timer and is designed to transmit real time-critical data telegrams using a scheduled real time control.
  • Such a real time-controlled Ethernet data network is defined by the PROFINET IRT Standard, for example.
  • Ethernet-based data networks which enable cycle times of a few milliseconds have been in use as field buses in automation systems.
  • applications such as control of complex drive systems, which require much shorter communication cycles in the millisecond range, for example.
  • the control of the drive systems is extremely time critical, i.e., they must be triggered at certain times to prevent malfunctions.
  • a communication system that can transmit real time-critical data in short communication cycles is therefore needed.
  • IRT Isochronous Real Time, i.e., a technology which permits a clock-controlled data transmission in real time.
  • PROFINET IRT systems make it possible to transmit real time-critical and non-real time-critical data in communication cycles of an adjustable chronological length over a switchable Ethernet data network. To do so, each communication cycle is subdivided into a first time domain, in which real time-critical data can be transmitted, and a second time domain, in which non-real time-critical data can be transmitted. To be able to ensure the required time precision in such a system, the points in time of transmitting or relaying the real time-critical data or real time-critical data telegrams are scheduled.
  • the PROFINET IRT Standard provides in this regard that the forwarding, sending and receiving points in time of the real time-critical data telegrams to be transmitted are saved in all participating coupling equipment and consumers, which capable of relaying, sending and/or receiving the real time-critical data telegrams, and namely more advantageously before the start of the data transmission.
  • Coupling equipment and consumers must therefore be capable of forwarding and/or sending PROFINET IRT data telegrams in the millisecond range.
  • the coupling equipment and consumers need special hardware components, which are available on the market.
  • each IRT-capable coupling unit and each IRT-capable consumer have their own clocks, which are synchronized with one another using an essentially known standardized method.
  • a method is defined by the IEEE 1588 standard, for example.
  • non-IRT-capable equipment for example, standard Ethernet devices must not be used between the IRT-capable coupling equipment and IRT-capable consumers.
  • the present invention is now based on the problem providing a communication system and a method for isochronous data transmission with which components that are not capable of a real time-controlled data transmission can transmit real time-critical data over a real time-controlled Ethernet data network without any impairment of the time precision required for the real time-critical data transmission.
  • a basic idea of the present invention is to link up traditional communication equipment such as computers and the like which are not capable of a real time-controlled data transmission and would nevertheless like to enable real time-critical data transmission via a special bridge device to a real time-controlled Ethernet data network, for example, a PROFINET IRT system.
  • Such communication equipment has only a communication interface, for example, a standard Ethernet interface which is not suitable for transmission of real time-critical data with the time precision required for this purpose.
  • standard Ethernet communication equipment often cannot be expanded through additional cards because no more expansion sites are available due to the deep integration of Ethernet interfaces.
  • a communication system for isochronous data transmission comprising a real time-controlled Ethernet data network with at least one first communication device having a synchronized timer.
  • the first communication devices are designed to transmit real time-critical data telegrams using a scheduled real time control.
  • the first communication device may be designed as a coupling device, as a consumer or as a component having a consumer with an integrated coupling unit.
  • a communication system comprises at least one bridge device connected to the real time-controlled Ethernet data network.
  • At least one second communication device is connected to the bridge device by means of a non-real time-controlled communication link.
  • Such a communication link may be a standard Ethernet connection.
  • the second communication device has a device for supplying real time-critical data telegrams, each containing a predetermined transmission point in time and a communication interface for transmitting real time-critical data telegrams to the bridge device.
  • the communication interface for example, a standard Ethernet interface, a USB interface, a WLAN interface, a FireWire interface or a PCI interface—none of these support real time-controlled data transmission.
  • the bridge device in turn has a timer that is synchronized with the timers of the first communication devices, for example, being time synchronized or cycle synchronized.
  • the bridge device contains another device for analyzing the transmission point in time of a real time-critical data telegram coming from the second communication device and a control device which controls the forwarding of the respective real time-critical data telegram to the at least one first communication device of the Ethernet data network as a function of the transmission point in time analyzed.
  • an isochronous data transmission is understood to be a transmission of data in communication cycles with a predefined adjustable duration.
  • One advantage of this communication system may be seen in the fact that the second non-real time-controllable communication device can transmit real time-critical data to the real time-controlled Ethernet data network without disturbing the time precision required for the real time-controlled Ethernet data network. It should be emphasized here that the bridge device for relaying the real time-critical data telegrams coming from the first communication device does not require a transmission schedule.
  • phase information is advantageously also contained in the real time-critical data telegrams supplied by the second communication device.
  • the phase information also known as the cycle number, denotes a certain communication cycle within the Ethernet data network.
  • the transmission point in time which is also transmitted in such a real time-critical data telegram thus indicates the transmission point in time with respect to the defined communication cycle.
  • the analysis unit is therefore designed for analyzing the phase information of a received real time-critical data telegram.
  • the control unit of the bridge device controls the forwarding of the respective real time-critical data telegram in the desired communication cycle to the at least one first communication device as a function of the analyzed transmission point in time and the analyzed phase information.
  • the real time-controlled Ethernet data network forms a PROFINET IRT Ethernet data network.
  • the PROFINET IRT Ethernet data network is also referred to below as an IRT domain.
  • the first communication devices are designed according to the PROFINET IRT Standard.
  • the real time-critical data telegrams supplied by the second communication device have a data structure according to the PROFINET IRT Standard. This ensures that the real time-critical data telegrams supplied by the second communication device can be forwarded unchanged to the Ethernet data network.
  • the transmission point in time and/or the phase information is available at a predetermined location in the payload data field of the respective real time-critical data telegram. To do so, the start of the payload data is projected accordingly and the first communication device can easily mask out this information.
  • the number of a predetermined output port of the bridge device may be contained in each of the real time-critical data telegrams supplied by the second communication device. This achieves the result that the bridge device can output received real time-critical data telegrams at the selected output ports at the transmission point in time.
  • the bridge device may be implemented in a first communication device.
  • the bridge device may also perform the function of a PROFINET synchronization master or synchronization slave.
  • the bridge device also has a memory device for temporary storage of real time-critical data telegrams of the second communication device. This ensures that no real time-critical data telegrams to be forwarded are lost in the bridge device when more real time-critical data telegrams are arriving than being sent, for example.
  • the bridge device is designed for receiving real time-critical data telegrams generated by the first communication device and for forwarding these real time-critical data telegrams to the second communication device.
  • the bridge device is designed to write the reception time in a time critical data telegram coming from the first communication device.
  • the Ethernet data network comprises at least one first communication device that has a synchronized timer and is designed to transmit real time-critical data telegrams using a scheduled real time control.
  • At least one real time-critical data telegram is supplied to by a second communication device, wherein the real time-critical data telegram contains a predetermined transmission point in time.
  • the real time-critical data telegram is transmitted over a communication interface of the second communication device to a bridge device connected to the Ethernet data network area.
  • the communication interface which may be a standard Ethernet interface, is not capable of real time-controlled data transmission.
  • the bridge device has a timer, which is synchronized with the timer of the at least one first communication device.
  • the transmission point in time transmitted in the received real time-critical data telegram is then analyzed in the bridge device and monitored with the help of the timer.
  • the received real time-critical data telegram is forwarded by the bridge device to the at least one first communication device as soon as the transmission point in time has been reached.
  • the received real time-critical data telegram is expediently stored temporarily in the bridge device until the transmission point in time has been reached.
  • the real time-critical data telegram is forwarded already after the analysis of the transmission point in time, namely before being completely received by the bridge device.
  • phase information which defines the communication cycle within the Ethernet data network is also contained in the real time-critical data telegram supplied by the second communication device.
  • the phase information contained in the received real time-critical data telegram is analyzed in the bridge device.
  • the real time-critical data telegram is forwarded by the bridge device to at least one first communication device, namely in the defined communication cycle and at the defined transmission point in time.
  • the real time-controlled Ethernet data network forms a PROFINET IRT domain.
  • the first communication devices are designed according to the PROFINET IRT Standard.
  • the real time-critical data telegrams supplied by the first and/or second communication devices have a data structure according to the PROFINET IRT Standard.
  • the transmission point in time and/or the phase information and/or the output port number is/are written at a predetermined location within the payload data field of the real time-critical data telegram.
  • this data can be removed from the real time-critical data telegram before the latter is forwarded.
  • FIG. 1 shows an exemplary communication system, in which the invention is implemented
  • FIG. 2 shows a detailed block diagram of the IRT bridge shown in FIG. 1 ,
  • FIG. 3 shows the data structure of a PROFINET IRT data telegram
  • FIG. 4 shows a modified data structure of the data telegram illustrated in FIG. 3 in which the transmission point in time and phase information are written into the payload data field, and
  • FIG. 5 time charts to illustrate the functioning of the IRT bridge.
  • FIG. 1 shows an example of a communication system 5 , which can be used to control complex industrial drive systems in an automation environment.
  • a communication system 5 which can be used to control complex industrial drive systems in an automation environment.
  • For control of such drive systems it must be possible to transmit real time-critical data in very short cycle times, for example, in the ⁇ s range.
  • a real time-capable data transmission system on an Ethernet basis was developed under the name PROFINET IRT, which was mentioned with its essential features in the introduction to the description.
  • Such a PROFINET IRT system is preferably a component of the communication system 5 .
  • This system is labeled with reference numeral 40 in FIG. 1 .
  • This area of the communication system 5 is referred to below as an IRT domain or a real time-controlled Ethernet data network 40 .
  • the data network 40 may be a switched Ethernet data network.
  • PROFINET IRT system is disclosed in EP 1 388 238 B1 in particular.
  • the real time-controlled Ethernet data network 40 which is only diagramed schematically in FIG. 1 , is indicated by three Ethernet connections 70 , 75 and 77 , to which are connected, for example, two IRT-capable, i.e., real time-controllable communication devices 50 and 60 .
  • Each of these IRT-capable communication devices 50 , 60 comprises a consumer 52 or 62 , respectively, and has an essentially known coupling device 55 or 65 , respectively.
  • the consumers 52 and 62 may be essentially known IRT IO devices (slaves) such as actuators, sensors, drive systems and the like, IRT IO controllers (masters), computers and the like. It should be pointed out that consumers and coupling devices may also be separate communication devices.
  • schedules containing the transmission point in time for forwarding the real time-critical data telegrams to be transmitted are stored in the coupling devices 55 and 65 in the present case.
  • the coupling devices 55 and 65 are therefore also referred to as IRT-capable coupling devices.
  • the connecting links which belong to the transmission points in time and by which the real time-critical data telegrams are also forwarded may optionally also be saved.
  • the schedules are advantageously created before the actual data transmission and stored in the coupling devices.
  • Each IRT-capable coupling devices 55 and 65 thus knows when and at which output port a real time-critical data telegram is to be sent or forwarded.
  • each coupling device 55 and 65 has its own clock 57 and/or 67 . These two clocks are synchronized with one another.
  • the data to be transmitted is transmitted in communication cycles with an adjustable duration.
  • Each communication cycle is subdivided into two time domains.
  • the real time-critical data telegrams are transmitted in the first time domain, and the non-real time-critical data telegrams are transmitted in the second time domain.
  • the points in time when real time-critical data telegrams can be transmitted within the first time domain of a communication cycle are also fixedly predetermined.
  • PROFINET IRT systems operate with a time precision in the ⁇ s range.
  • Specially designed coupling devices 55 and 65 are needed to achieve this transmission accuracy. Corresponding modules with which the precise scheduling of the real time communication is ensured are already available on the market.
  • EP 1 388 238 B1 also discloses that consumers having only a standard Ethernet interface may be connected to an Ethernet connection of the IRT domain 40 . These consumers generate only non-real time-critical data that is transmitted exclusively in the second time domain of a communication cycle without interference in the real time communication.
  • IRT-capable hardware is required in the communication devices 50 and 60 to be able to transmit real time-critical data. Because of the deep integration of standard Ethernet interfaces, numerous communication devices, for example, PC architectures, no longer have any free expansion slots, so they cannot be used for a real time-critical data transmission within the IRT domain.
  • Such a communication interface in the present example is a standard Ethernet interface. This does not interfere with the real time-critical data communication guaranteed by the PROFINET IRT system.
  • the IRT bridge device 30 may also be referred to as a modified Ethernet switch.
  • FIG. 1 shows a non-IRT-capable communication device, for example, a traditional standard Ethernet computer 10 .
  • the computer 10 contains only one standard Ethernet interface 12 by means of which it is connected to the IRT bridge device 30 via an Ethernet cable of a standard Ethernet data network 20 .
  • multiple standard Ethernet devices can be connected to the IRT bridge device 30 or to another IRT bridge device via the standard Ethernet data network 20 .
  • the term “standard Ethernet data network” expresses the fact that real time-critical data cannot be transmitted with a high time precision over such a data network. It should be pointed out that in the present case the standard Ethernet data network and the standard Ethernet computer are used only as examples of devices that do not have any IRT capability.
  • the computer 10 is designed to generate PROFINET IRT-compatible data telegrams, which can be transmitted over the IRT domain 40 .
  • FIG. 3 shows an example of a data structure of a PROFINET IRT data telegram.
  • the IRT-capable communication devices 50 and 60 can transmit such data telegrams.
  • the PROFINET IRT data telegram shown here contains a header, which has the destination address DA and the source address SA, for example. Instead of the destination address DA, an MCFF address which supports the MultiCast Fast Forwarding Technology of the PROFINET IRT system, which is known per se, may also be used.
  • the “VLAN” and “PRIO2” data fields serve to control non-real time-critical data telegrams.
  • the coupling devices 55 and 65 and also the IRT bridge device 30 can recognize PROFINET IRT data telegrams on the basis of the data fields “Ethernet-type PROFINET” and “FID.”
  • the PROFINET IRT data telegram shown here contains a payload data field, a padding field and a checksum field FCS.
  • the padding field is necessary so that the data telegram is no less than 64 bits even if the payload data length is smaller. Ethernet compatibility can therefore be guaranteed.
  • the coupling devices 55 and 65 have schedules which stipulate precisely when a PROFINET IRT data telegram is to be sent. No such schedule is provided in the IRT bridge device 30 .
  • the computer 10 has software, which enables it to write the desired transmission point in time SZ and optionally a phase information P in the payload data field of a PROFINET IRT data telegram to be transmitted, which has the data structure shown in FIG. 4 .
  • the phase information P corresponds to the number of a communication cycle within the IRT domain 40 .
  • the computer 10 can also write the number of an output port of the IRT bridge device 30 in the payload data field.
  • the phase information P, the transmission point in time SZ and the output port number stand at a predetermined location within the payload data field, so that the IRT bridge device 30 can read this information out of the payload data field of a received data telegram.
  • the basic design of the IRT bridge device 30 is shown in FIG. 2 .
  • the IRT bridge device 30 has an analysis unit 31 , which can analyze the transmission point in time, the output port number and the phase information contained in the payload data field of a received PROFINET IRT data telegram. It should be emphasized here that the transmission point in time, the phase information and the output port number are all information for the IRT bridge device for time control of real time-critical data telegrams of the computer 10 .
  • the IRT bridge device 30 has a memory 32 , in which the data telegrams coming from the computer 10 , which may be real time-critical and non-real time-critical data telegrams, are stored temporarily.
  • a timer 34 which is synchronized in time with the timers 57 and 67 of the coupling devices 55 and 65 , is also provided. Methods of synchronizing the timers in a PROFINET IRT system are sufficiently well known and therefore need not be described further here. It is important only that these timers are synchronized with a high precision, i.e., in the ⁇ s range, for example, to enable a chronologically precise control of drive systems.
  • the IRT bridge device 30 may have a switching device 35 , which can send real time-critical data telegrams that are to be forwarded to a certain output port of the IRT bridge device 30 as a function of the output port number contained in the payload data field.
  • the IRT bridge device 30 has three output ports 36 , 37 and 38 .
  • Control and monitoring of the IRT bridge device 30 and its components may be executed by a programmable control unit, for example, a microprocessor 33 .
  • a cycle counter 39 may also be provided in the IRT bridge device 30 and can be synchronized with a cycle counter of the IRT domain 40 , known as a CycleCounter.
  • the computer 10 would like to transmit multiple real time-critical PROFINET IRT data telegrams and non-real time-critical data telegrams over the standard Ethernet interface 12 . These data telegrams are transmitted, for example, over the standard Ethernet data network 20 to the IRT bridge device 30 in communication cycles according to the non-real time-capable PROFINET IRT Standard. As shown in the time chart on the left in FIG. 5 , the computer 10 sends six real time-critical modified PROFINET IRT data telegrams, for example, over its standard Ethernet interface 12 , the data structure of which is shown in FIG. 4 as an example, and sends three non-real time-critical data telegrams in a communication cycle to the IRT bridge device 30 .
  • the computer 10 writes at least the desired transmission point in time in the payload data field of each real time-critical data telegram.
  • the computer 10 writes the phase information P 1 and the transmission point in time t 1 into the payload data field of the first real time-critical data telegram. This information goes to the IRT bridge device 30 of the communication cycle and the transmission point in time within this communication cycle when the real time-critical data frame must be transmitted.
  • the computer 10 writes the phase information P 1 and a different point in time t 2 in the payload data field of the second real time-critical data telegram to be transmitted.
  • the computer 10 writes the phase information P 1 and the transmission point in time t 3 in the payload data field of the third real time-critical data telegram to be transmitted while the payload data field of the fourth real time-critical data telegram to be transmitted contains the phase information P 1 and the transmission point in time t 4 .
  • the first four real time-critical data telegrams should be forwarded at four different times within the first communication cycle from the IRT bridge device 30 to the IRT domain 40 .
  • the payload data field of the fifth real time-critical data telegram to be transmitted contains the phase information P 2 and the transmission point in time t 1 .
  • the phase information P 2 indicates that this real time-critical data telegram must be transmitted in the second communication cycle of the IRT domain 40 .
  • the payload data field of the sixth data telegram to be transmitted contains the phase information P 2 and the transmission point in time t 2 .
  • These six real time-critical data telegrams to be transmitted may all have the data structure of a modified PROFINET IRT data telegram as shown in FIG. 4 .
  • the output port number which indicates over which of the three output ports 36 , 37 and 38 the respective real time-critical data telegram is to be transmitted may optionally be contained in the payload data field of the six real time-critical data telegrams to be transmitted. In the present example, it is assumed that the payload data fields do not contain any output port number. For this application case, the IRT bridge device 30 may be adjusted so that all real time-critical data telegrams are sent over the output port 36 to the IRT domain 40 .
  • the analysis unit 31 can recognize the real time-critical data telegrams of the computer 10 on the basis of the “Ethernet-type PROFINET” and “FID” fields.
  • the analysis device 31 Ascertains that the first real time-critical data telegram of the computer 10 has arrived, it reads the transmission point in time t 1 and the phase information P 1 out of the predetermined location in the payload data field. Similarly, the analysis unit 31 analyzes the five additional real time-critical data telegrams of the computer 10 . Some or all of the data telegrams of the computer 10 may be stored in the memory 32 of the IRT bridge device 30 .
  • the information that has been analyzed and an identification of the respective real time-critical data telegrams can be saved in a lookup table in the IRT bridge device 30 .
  • the microprocessor 33 monitors the timer 34 , the cycle counter 39 and optionally the lookup table.
  • the communication cycles of the IRT domain 40 each have a first range in which real time-critical data telegrams are transmitted and a second range in which non-time-critical data telegrams are transmitted.
  • the first time domain of a communication cycle of the IRT domain 40 comprises four transmission points in time T 1 , T 2 , T 3 and T 4 , which are fixedly defined.
  • the first real time-critical data telegram is sent via the switch 35 to the output port 36 and from there is forwarded to the IRT domain 40 at time t 1 in the first communication cycle.
  • the data telegram is transmitted to the consumer 62 , for example.
  • the microprocessor 33 ensures that the second real time-critical data telegram is forwarded to the IRT domain 40 at the transmission point in time t 2 of the first communication cycle, the third real time-critical data telegram is forwarded at the transmission point in time t 3 of the first communication cycle and the fourth real time-critical data telegram is transmitted at the transmission point in time t 4 of the first communication cycle.
  • the three non-real time-critical data telegrams of the computer 10 may be forwarded to the IRT domain 40 in the second time domain of the first communication cycle, as shown in FIG. 5 .
  • the IRT bridge device 30 recognizes the non-real time-critical data telegrams of the computer 10 on the basis of the data in the “VLAN” and “PRIO” fields of a PROFINET IRT data telegram.
  • the PROFINET rules for transmission of non-real time-critical data telegrams, which are essentially known, are taken into account here by the IRT bridge device 30 .
  • the microprocessor 33 In response to the results of the analysis device 31 , which may be stored in the lookup table mentioned above, the microprocessor 33 knows that the fifth and sixth real time-critical data telegrams must be forwarded in the second communication cycle.
  • the microprocessor 33 still monitors the timer 34 and the cycle counter 39 . As soon as the microprocessor 33 has recognized that the transmission point in time t 1 contained in the fifth real time-critical data telegram corresponds to the current time of the timer 34 , and that the phase information P 2 corresponds to the current value of the cycle counter 39 , the fifth real time-critical data telegram is read out of the memory 32 and sent via the switch 35 to the output port 36 and from there is forwarded to the IRT domain 40 at time t 1 in the second communication cycle. Depending on the destination address DA, the data telegram is transmitted to the consumer 52 , for example. Similarly, the microprocessor 33 ensures that the sixth real time-critical data telegram is forwarded to the IRT domain 40 at the transmission point in time t 2 of the second communication cycle, as illustrated in FIG. 5 .
  • the real time-critical data telegrams can already be forwarded by the IRT bridge device 30 as soon as the analysis device 31 has analyzed the phase information P and the transmission point in time SZ without the respective data telegram having been completely received or already stored completely in the memory 32 .
  • the IRT bridge device 30 can forward unchanged the real time-critical data telegrams coming from the computer 10 to the IRT domain, depending on the implementation.
  • the IRT bridge 30 can remove the transmission point in time SZ and optionally the phase information P as well as the output number from the payload data field before forwarding a received real time-critical data telegram because this information is then no longer needed in the IRT domain 40 .
  • the IRT bridge device 30 may also be arranged inside the communication device 50 or 60 , for example. It is also conceivable for the IRT bridge device to also be able to perform the function of a PROFINET synchronization master, which has long been known.
  • the coupling devices 55 and 65 know the exact position of the payload data within a PROFINET IRT data telegram and are thus capable of masking out the phase information and the transmission point in time within a payload data field. This permits transparent forwarding of the real time-critical data telegrams supplied by the computer 10 within the IRT domain without having to make any changes in the existing hardware.
  • the IRT-capable communication devices can transmit real time-critical data telegrams to the bridge device 30 according to the data structure shown in FIG. 3 .
  • the bridge device 30 can write the respective reception time into the received real time-critical data telegrams before forwarding the data telegram to the computer 10 .

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US13/809,195 2010-07-14 2011-07-07 Communication system and method for isochronous data transmission in real time Active 2032-01-02 US9270481B2 (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
DE102010027167 2010-07-14
DE102010027167.5 2010-07-14
DE201010027167 DE102010027167B4 (de) 2010-07-14 2010-07-14 Kommunikationssystem und Verfahren zur isochronen Datenübertragung in Echtzeit
DE102010052322 2010-11-25
DE201010052322 DE102010052322A1 (de) 2010-11-25 2010-11-25 Kommunikationssystem und Verfahren zur isochronen Datenübertragung in Echtzeit
DE102010052322.4 2010-11-25
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11256641B2 (en) * 2017-01-27 2022-02-22 National Instruments Corporation Asynchronous start for timed functions

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103237091B (zh) * 2013-04-24 2016-04-06 中国东方电气集团有限公司 一种具有实时性的profinet总线接口装置
US9137044B2 (en) 2013-10-15 2015-09-15 National Instruments Corporation System and method for interoperability between multiple networks
US9967209B2 (en) * 2013-10-15 2018-05-08 National Instruments Corporation Switch for scheduled data egress
US9288157B2 (en) * 2013-10-15 2016-03-15 National Instruments Corporation Time-sensitive switch for scheduled data egress
DE102014112901A1 (de) * 2014-09-08 2016-03-10 Phoenix Contact Gmbh & Co. Kg Kommunikationseinrichtung, Kommunikationssystem und Verfahren zum synchronisierten Senden von Telegrammen
EP3038325B1 (de) * 2014-12-22 2019-12-11 Siemens Aktiengesellschaft Verfahren zur datenübermittlung in einem kommunikationsnetz eines industriellen automatisierungssystems und koppel-kommunikationsgerät
CN106330377B (zh) * 2016-08-25 2018-04-13 中车青岛四方车辆研究所有限公司 轨道列车宽带网络实时性数据传输系统及方法
DE102017119578A1 (de) * 2017-08-25 2019-02-28 Phoenix Contact Gmbh & Co. Kg Verfahren zur Übertragung von Daten zwischen einer zentralen Steuereinrichtung und einer Mehrzahl dezentraler Geräte und entsprechende Vorrichtungen
DE102019203001A1 (de) * 2019-03-06 2020-09-10 Robert Bosch Gmbh Verfahren und Vorrichtung zum Betreiben eines TSN-Kommunikationssystems
CN116074159B (zh) * 2021-11-04 2024-06-07 中国电信股份有限公司 工业pon系统中基于设备映射表实现业务隔离的方法及装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020064157A1 (en) * 2000-11-24 2002-05-30 Karl-Heinz Krause System and method for the parallel transmission of real-time-critical and non-real-time critical data via switched data networks, especially the Ethernet
WO2003027784A2 (de) 2001-09-26 2003-04-03 Siemens Aktiengesellschaft Verfahren zur übertragung eines datentelegramms zwischen einer echtzeit-domain und einer nicht-echtzeit-domain und koppeleinheit
DE10228823A1 (de) 2001-09-26 2003-04-17 Siemens Ag Verfahren zum Betrieb eines isochronen, zyklischen Kommunikationssystems
WO2003036832A2 (de) 2001-10-17 2003-05-01 Siemens Aktiengesellschaft Verfahren zum betrieb eines endteilnehmers eines isochronen, zyklischen kommunikationssystems
US20050041690A1 (en) * 2001-09-26 2005-02-24 Siemens Aktiengesellschaft Method for transmitting real-time data messages in a cyclic communications system
US7420985B2 (en) * 2001-09-26 2008-09-02 Siemens Aktiengesellschaft Method for operating an isochronous cyclic communication system

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020064157A1 (en) * 2000-11-24 2002-05-30 Karl-Heinz Krause System and method for the parallel transmission of real-time-critical and non-real-time critical data via switched data networks, especially the Ethernet
WO2002043336A1 (de) 2000-11-24 2002-05-30 Siemens Aktiengesellschaft System und verfahren zur parallelen übertragung von echtzeitkritischen und nicht echtzeitkritischen daten über schaltbare datennetze, insbesondere ethernet
WO2003027784A2 (de) 2001-09-26 2003-04-03 Siemens Aktiengesellschaft Verfahren zur übertragung eines datentelegramms zwischen einer echtzeit-domain und einer nicht-echtzeit-domain und koppeleinheit
DE10228823A1 (de) 2001-09-26 2003-04-17 Siemens Ag Verfahren zum Betrieb eines isochronen, zyklischen Kommunikationssystems
US20040246988A1 (en) 2001-09-26 2004-12-09 Dieter Bruckner Method for transmitting a data telegram between a real-time domain and a non-real-time domain and a coupling unit
US20050041690A1 (en) * 2001-09-26 2005-02-24 Siemens Aktiengesellschaft Method for transmitting real-time data messages in a cyclic communications system
US7420985B2 (en) * 2001-09-26 2008-09-02 Siemens Aktiengesellschaft Method for operating an isochronous cyclic communication system
US7852879B2 (en) * 2001-09-26 2010-12-14 Siemens Aktiengesellschaft Method for transmitting real-time data messages in a cyclic communications system
WO2003036832A2 (de) 2001-10-17 2003-05-01 Siemens Aktiengesellschaft Verfahren zum betrieb eines endteilnehmers eines isochronen, zyklischen kommunikationssystems
CN1572075A (zh) 2001-10-17 2005-01-26 西门子公司 用于运行等时、周期通信系统的终端用户的方法
US7460560B2 (en) * 2001-10-17 2008-12-02 Siemens Aktiengesellschaft Method for operating an end-user of an isochronous cyclical communication system

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
Examiner: Qin Xiaofang, "Related Chinese Application No. CN 2011 80034777.4", Dec. 3, 2014, Publisher: SIPO, Published in: CN.
Examiner: Sergio Lupia, "Co-Pending EP Patent Application No. EP 11 731 265.2", "EP Office Action", Jan. 5, 2015, Publisher: EPO, Published in: EP.
Examiner: Sergio Lupia, "Related EP Application No. EP 11 731 265.2", "Examination Report", Jan. 5, 2015, Publisher: EPO, Published in: EP.
Sergio Lupia, "International Patent Application No. PCT/EP2011/003380 International Search Report", Aug. 29, 2011, Publisher: PCT, Published in: EP.
Zdenek Hanzalek, et al., "Profinet IO IRT Message Scheduling With Temporal Constraints", "IEEE Transactions on Industrial Informatics", Jul. 1, 2010, pp. 369-380, vol. 6, No. 3, Publisher: IEEE Service Center, New York, NY ISSN: 1551-3203, Published in: US.

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11256641B2 (en) * 2017-01-27 2022-02-22 National Instruments Corporation Asynchronous start for timed functions

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