# US 8,543,260 B2 · Methods and systems for evaluation of signal propagation across disparate time domains > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,260 B2 - Document ID: US8543260B2 - Status: Granted - Kind: B2 - Application number: 13/039,416 - Filed: 2011-03-03 - Published: 2012-09-06 - Granted: 2013-09-24 - Earliest claimed: 2011-03-03 - Assignees: The Boeing Company - Applicants: Luigi P. Righi; Gregory M. Wellbrook; Mark A. Talbot - Inventors: Luigi P. Righi; Gregory M. Wellbrook; Mark A. Talbot - Web page: https://patentgrep.com/patent/US8543260B2 ## CPC - H04L 43/04: Processing captured monitoring data, e.g. for logfile generation - H04L 12/40019: {Details regarding a bus master} - H04L 43/106: using time related information in packets, e.g. by adding timestamps - H04L 67/12: specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks - H04L 2012/4028: {the transportation system being an aircraft} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for correlating, in time, selected events that are memorialized as data within messages transmitted across disparate communications busses is described. The method includes receiving, with a referencing unit, the messages that are transmitted across the disparate communications busses, referencing, with the referencing unit, the content of a first selected received message to a master clock within the referencing unit, referencing, with the referencing unit, the content of a second selected received message to the master clock within the referencing unit, the second selected received message related to the first selected message, the second selected received message occurring on a communications bus disparate from the communications bus upon which the first received message occurred, and providing, based on operation of the master clock, a common time reference for the content of both the first selected received message and the second selected received message. ## Claims ### Claim 1 A method for correlating, in time, selected events that are memorialized as data within messages transmitted across disparate communications busses, said method comprising: receiving, with a referencing unit, the messages that are transmitted across the disparate communications busses; referencing, with the referencing unit, the content of a first selected received message to a master clock within the referencing unit; referencing, with the referencing unit, the content of a second selected received message to the master clock within the referencing unit, the second selected received message related to the first selected message, the second selected received message occurring on a communications bus disparate from the communications bus upon which the first received message occurred; and providing, based on operation of the master clock, a common time reference for the content of both the first selected received message and the second selected received message. ### Claim 2 (depends on 1) The method according to claim 1 wherein receiving the messages that are transmitted across the disparate communications busses comprises coupling the referencing unit to each of the disparate communications busses of interest. ### Claim 3 (depends on 1) The method according to claim 1 wherein the messages that are transmitted across the disparate communications busses comprises messages transmitted between various line replaceable units of an aircraft across a plurality of disparate communications busses. ### Claim 4 (depends on 3) The method according to claim 3 wherein the messages comprise one or more of Mil-Std-1553 messages and ARINC-429 messages. ### Claim 5 (depends on 1) The method according to claim 1 further comprising forwarding the common time reference to an external device for analysis. ### Claim 6 (depends on 1) The method according to claim 1 wherein referencing comprises syncing instances of a parameter occurring in the first selected received message and the second selected received message to determine a true propagation delay across the disparate communications busses. ### Claim 7 (depends on 1) The method according to claim 1 wherein providing comprises operating a processing device to provide relevant timing of events that occur on the disparate communications busses to an external interface for transmission to at least one of an end user and an external computing device. ### Claim 8 (depends on 1) The method according to claim 1 wherein referencing comprises: monitoring the first selected received message to determine when an event occurs; and providing a common time reference for the event occurrence when the event occurrence appears in the second selected received message. ### Claim 9 An avionics system comprising: a plurality of line replaceable units; at least two disparate busses communicatively coupling said plurality of line replaceable units; and a referencing unit communicatively coupled to receive messages occurring on said at least two disparate busses, said referencing unit comprising a master clock and programmed to: reference the content of a first selected received message occurring on a first of said disparate busses to said master clock within the referencing unit; reference the content of a second selected received message to the master clock within the referencing unit, the second selected received message containing a parameter also contained within the first selected received message, the second selected received message occurring on a communications bus disparate from the communications bus upon which the first selected received message occurred; and provide, based on operation of said master clock, a common time reference for occurrence of the parameter in both the first selected received message and the second selected received message. ### Claim 10 (depends on 9) The avionics unit according to claim 9 wherein said at least two disparate busses comprises one or both of Mil-Std-1553 busses and ARINC-429 busses. ### Claim 11 (depends on 9) The avionics unit according to claim 9 wherein said referencing unit comprises an external interface operable for forwarding the common time references for occurrence of the parameter to an external device. ### Claim 12 (depends on 9) The avionics unit according to claim 9 wherein said referencing unit is programmed to sync instances of a parameter occurring in the first selected received message and the second selected received message to determine a true propagation delay across said disparate communications busses. ### Claim 13 (depends on 9) The avionics unit according to claim 9 wherein said referencing unit comprises an external interface, said referencing unit programmed to provide data indicative of relevant timing of events that occur as indicated by data within the messages transmitted across said disparate communications busses to said external interface for transmission to at least one of an end user and an external computing device. ### Claim 14 (depends on 13) The avionics unit according to claim 13 wherein to provide data indicative of relevant timing of event occurrences, said referencing unit is programmed to: monitor the first selected received message to determine when an event occurs; and provide a common time reference for the event occurrence when the event occurrence appears in the second selected received message. ### Claim 15 A referencing unit comprising: a processing device; a master clock coupled to said processing device; and a plurality of receivers communicatively coupled to said processing device and said master clock, said receivers each operable for communicative coupling to a communications bus, said referencing unit programmed to: reference the content of a first message received at a first of said receivers from a first communications bus to said master clock; reference the content of a second message received at a second of said receivers from a second communications bus, disparate from the first communications bus, to said master clock, the second message containing a parameter also contained within the first message; and generate a common time reference for occurrence of the parameter in both the first message and the second message. ### Claim 16 (depends on 15) The referencing unit according to claim 15 wherein said receivers are compatible with at least one of a Mil-Std-1553 bus and an ARINC-429 bus. ### Claim 17 (depends on 15) The referencing unit according to claim 15 wherein said referencing unit comprises an external interface communicatively coupled to said processing device operable for forwarding the common time reference for the parameter to an external device. ### Claim 18 (depends on 15) The referencing unit according to claim 15 wherein said processing device is programmed to sync instances of a parameter occurring in both the first message and the second message to determine a true propagation delay across the first and the second communications busses.