Method for Monitoring, at the Correct Time, TT Ethernet Messages

• US 20150043360A1
• Filed: 12/18/2012
• Published: 02/12/2015
• Est. Priority Date: 12/19/2011
• Status: Active Grant

• Current Assignee: TTTech Computertechnik AG
• Original Assignee: FTS Computertechnik GmbH
• Inventors: Poledna, Stefan
• Granted Patent: US 9,614,744 B2
• Time in Patent Office: Days
• US Class Current: 370/250
• CPC Class Codes: H04L 12/43 with synchronous transmission, e.g. time division multiplex [TDM], slotted rings
• CPC Class Codes: H04L 43/026 using flow identification
• CPC Class Codes: H04L 43/0858 One way delays
• CPC Class Codes: H04L 43/106 using time related information in packets, e.g. by adding timestamps

Abstract

The invention relates to a method for monitoring, at the correct time, TTEthernet (TT) messages communicated by a TTEthernet switch (TTE switch) in a distributed real-time computer system. According to the invention, the TTE switch has a global time having precision P and accuracy A, and the TTE switch has a plurality of communication channels and one or more monitoring channels, and the TTE switch contains a selection data structure that specifies which TT message classes are to be monitored, and a copy of a TT message which belongs to a TT message class selected for monitoring is formed in the TTE switch and is transmitted by the TTE switch via a monitoring channel to a monitoring node, and the TTE switch subsequently autonomously transmits an ET message containing an identifier and the exact transmission time of the monitored TT message via a monitoring channel to a monitoring node.

Claims

1. Method for the time-correct monitoring of TTEthernet (TT) messages transmitted by a TTEthernet switch in a distributed real-time computer system characterized in that the TTE switch is a equipped with a global time with the precision P and the accuracy A, and whereby the TTE switch contains a plurality of communication channels and one or multiple monitoring channels, and whereby the TTE switch contains a selection data structure indicating which TT message classes shall be monitored, and whereby in the TTE switch a copy of a TT message belonging to the selected message class is generated, which is sent by the TTE switch via a monitoring channel to a monitoring node, and wherein the TTE switch subsequently autonomously sends an ET message containing an identifier and the exact time of transmission of the monitored TT message via a monitoring channel to a monitoring node.

2. Method according to claim 1 characterized in that the ET message autonomously generated by the TTE switch is sent after a multiplicity of TT messages selected to be monitored, whereby the data field of the ET message contains the identifiers and the exact times of transmission of all TT messages creating the multiplicity.

3. Method according to claim 1 characterized in that the selection data structure is loaded dynamically into the TTE switch.

4. Method according to claim 1 characterized in that a change of the selection data structure is secured by cryptographic protocols.

5. Method according to one of claims 1 characterized in that in addition to the TT messages, ET messages being transmitted by the TTE switch can also be selected for monitoring.

6. Method according to claim 1 characterized in that the monitoring channel supports a higher bandwidth than the communication channels.

7. Method according to claim 1 characterized in that all time-derived transmission events represent sparse events.

8. Method according to claim 1 characterized in that every TT message contains a parameter field to which a value of TRUE or FALSE is assigned by a sender, and wherein a message with a parameter field value of TRUE is copied by the TTE switch and sent to the monitoring channel, and wherein a message with a parameter field value of FALSE is not sent by the TTE switch to the monitoring channel.

9. TTEthernet switch (TTE switch) for a distributed real-time computer system, wherein the distributed real-time computer system consists of a plurality of node computers and TTE switches, and wherein the TTE switch transmits TTEthernet (TT) messages within the distributed real-time computer system characterized in that the TTE switch is equipped with a global time with the precision P and the accuracy A, and whereby the TTE switch exhibits a plurality of communication channels and one or multiple monitoring channels, and whereby the TTE switch contains a selection data structure indicating which TT message classes shall be monitored, and whereby in the TTE switch a copy of a message belonging to the selected message class is generated, which is sent by the TTE switch via a monitoring channel to a monitoring node, and wherein the TTE switch subsequently autonomously sends an ET message containing an identifier and the exact time of transmission of the monitored TT message via a monitoring channel to a monitoring node.

10. TTE switch according to claim 9 characterized in that the ET message autonomously generated by the TTE switch is sent after a multiplicity of TT messages selected to be monitored, whereby the data field of the ET message contains the identifiers and the exact times of transmission of all TT messages creating the multiplicity.

11. TTE switch according to claim 9 characterized in that the selection data structure is loaded dynamically into the TTE switch.

12. TTE switch according to claim 9 characterized in that a change of the selection data structure is secured by cryptographic protocols.

13. TTE switch according to claim 9 characterized in that in addition to the TT messages, ET messages being transmitted by the TTE switch can also be selected for monitoring.

14. TTE switch according to claim 9 characterized in that the monitoring channel supports a higher bandwidth than the transmission channels.

15. TTE switch according to claim 9 characterized in that all time-derived transmission events represent sparse events.

16. TTE Switch according to claim 9 characterized in that every TT message contains a parameter field to which a value of TRUE or FALSE is assigned by a sender, and wherein a message with a parameter field value of TRUE is copied by the TTE switch and sent to the monitoring channel, and wherein a message with a parameter field value of FALSE is not sent by the TTE switch to the monitoring channel.

17. Real-time computer system, comprising a plurality of node computers and TTE switches, comprising at least one TTE switch according to claim 9.

18. Real-time computer system according to claim 17 characterized in that two or multiple TTE switches support monitoring channels, whereby the monitoring channels of the TTE switches are connected to one or multiple monitoring nodes.

19. Distributed real-time computer architecture characterized in that in a distributed real-time computer system according to claim 17 composed of a multiplicity of node computers and TTE switches and in which two or multiple TTE switches support monitoring channels, the monitoring channels of the TTE switches are connected to one or multiple monitoring nodes.