# US 12,003,613 B2 · Method for synchronizing time in an ethernet-based network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,613 B2 - Document ID: US12003613B2 - Status: Granted - Kind: B2 - Application number: 17/685,978 - Filed: 2022-03-03 - Published: 2022-08-25 - Granted: 2024-06-04 - Earliest claimed: 2019-09-23 - Assignees: Beckhoff Automation GmbH - Applicants: Beckhoff Automation GmbH - Inventors: Holger Büttner; Dirk Janssen; Erik Vonnahme; Hans Beckhoff; Thomas Rettig; Thorsten Bunte; Johannes Beckhoff; Guido Beckmann; Karl Weber - Web page: https://patentgrep.com/patent/US12003613B2 ## CPC - H04L 7/10: Arrangements for initial synchronisation - H04L 12/40019: {Details regarding a bus master} - H04J 3/0667: {Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864)} - H04L 7/0012: {by comparing receiver clock with transmitter clock} - H04L 2012/4026: {Bus for use in automation systems} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) ## Abstract A method for synchronizing time in an Ethernet-based network having a master network subscriber and a slave network subscriber includes sending out a first telegram via the master network subscriber, where the slave subscriber receives the first telegram at a first receipt time value of a local system time and stores the first receipt time value. The method can also include reading out the first receipt time value via the master subscriber, sending out a second telegram by the master subscriber, where the slave subscriber receives the second telegram at a second receipt time value of the local system time and stores the second receipt time value, and reading out the second receipt time value via the master network subscriber. A speed parameter of the local system time can be calculated from the receipt time values via the master network subscriber, and transmitted to the slave subscriber. ## Claims ### Claim 1 A method for synchronizing time in an Ethernet-based network having at least a master network subscriber and a slave network subscriber, the method comprising: sending out a first telegram by the master network subscriber, wherein the slave network subscriber receives the first telegram at a first receipt time value of a local system time of the slave network subscriber and stores the first receipt time value; reading out the first receipt time value by the master subscriber; sending out a second telegram by the master network subscriber, wherein the slave network subscriber receives the second telegram at a second receipt time value of the local system time of the slave network subscriber and stores the second receipt time value; reading out the second receipt time value by the master network subscriber; calculating a speed parameter of the local system time of the slave network subscriber, the master network subscriber using the first receipt time value and the second receipt time value; and transmitting the speed parameter to the slave network subscriber; wherein the second telegram is sent out between 0.1 seconds and 10 seconds after the first telegram. ### Claim 2 (depends on 1) The method according to claim 1, wherein the network comprises a further slave network subscriber, wherein the further slave network subscriber receives the first telegram at a further first receipt time value of a local system time of the further slave network subscriber and stores the further first receipt time value, wherein the further first receipt time value is read out by the master network subscriber, wherein the further slave network subscriber receives the second telegram at a further second receipt time value of the local system time of the further slave network subscriber and stores the further second receipt time value, wherein the further second receipt time value is read out by the master network subscriber, wherein the master network subscriber calculates a further speed parameter of the local system time of the further slave network subscriber from the further receipt time values, and wherein the further speed parameter is transmitted to the further slave network subscriber. ### Claim 3 (depends on 1) The method of claim 1, wherein the second telegram is sent out between 0.2 seconds and 5 seconds after the first telegram. ### Claim 4 A method for synchronizing time in an Ethernet-based network having at least a master network subscriber, a slave network subscriber and a further slave network subscriber, the method comprising: sending out a first telegram by the master network subscriber, wherein the slave network subscriber receives the first telegram at a first receipt time value of a local system time of the slave network subscriber and stores the first receipt time value; wherein the further slave network subscriber receives the first telegram at a further first receipt time value of a local system time of the further slave network subscriber and stores the further first receipt time value; reading out the first receipt time value and the further first receipt time value by the master subscriber; sending out a second telegram by the master network subscriber, wherein the slave network subscriber receives the second telegram at a second receipt time value of the local system time of the slave network subscriber and stores the second receipt time value; wherein the further slave network subscriber receives the second telegram at a further second receipt time value of a local system time of the further slave network subscriber and stores the further second receipt time value; reading out the second receipt time value and the further second receipt time value by the master network subscriber; calculating a speed parameter of the local system time of the slave network subscriber, the master network subscriber using the first receipt time value and the second receipt time value; wherein the master network subscriber calculates a further speed parameter of the local system time of the further slave network subscriber from the further receipt time values; and transmitting the speed parameter to the slave network subscriber and the further speed parameter to the further slave network subscriber. ### Claim 5 (depends on 4) The method according to claim 4, wherein the master network subscriber calculates a reference time difference as a difference between the first reference time value and the second reference time value and calculates a receipt time difference as a difference between the first receipt time value and the second receipt time value, and wherein the master network subscriber calculates the speed parameter from the reference time difference and the receipt time difference. ### Claim 6 (depends on 4) The method according to claim 4, wherein the second telegram is sent out between 0.1 seconds and 10 seconds after the first telegram. ### Claim 7 (depends on 6) The method of claim 6, wherein the second telegram is sent out between 0.2 seconds and 5 seconds after the first telegram. ### Claim 8 (depends on 4) The method according to claim 4, wherein transmitting the speed parameter is carried out by the master network subscriber by sending out a transmission telegram. ### Claim 9 (depends on 4) The method according to claim 4, wherein the method is carried out during initialization of the network. ### Claim 10 (depends on 4) The method according to claim 4, wherein the speed parameter is stored in a non-volatile data memory of the master network subscriber. ### Claim 11 (depends on 4) The method according to claim 4, wherein the network is an EtherCAT network. ### Claim 12 (depends on 4) The method according to claim 4, wherein the network comprises a reference time provider, wherein the reference time provider receives the first telegram at a first reference time value of a local system time of the reference time provider and stores the first reference time value, wherein the first reference time value is read out by the master network subscriber, wherein the reference time provider receives the second telegram at a second reference time value of a local system time of the reference time provider and stores the second reference time value, wherein the second reference time value is read out by the master network subscriber, and wherein the speed parameter is calculated from the receipt time values and the reference time values. ### Claim 13 (depends on 4) The method according to claim 4, wherein the master network subscriber sends out the first telegram at a first reference time value of a system time of the master network subscriber, wherein the master network subscriber sends out the second telegram at a second reference time value of the system time of the master network subscriber, and wherein the speed parameter is calculated from the receipt time values and the reference time values. ### Claim 14 (depends on 4) The method according to claim 4, wherein reading out of the first receipt time value is carried out by the master network subscriber by sending out a first read-out telegram, and wherein reading out of the second receipt time value is carried out by the master network subscriber by sending out a second read-out telegram. ### Claim 15 A method for synchronizing time in an Ethernet-based network having at least a master network subscriber and a slave network subscriber, the method comprising: sending out a first telegram by the master network subscriber, wherein the slave network subscriber receives the first telegram at a first receipt time value of a local system time of the slave network subscriber and stores the first receipt time value; reading out the first receipt time value by the master subscriber; sending out a second telegram by the master network subscriber, wherein the slave network subscriber receives the second telegram at a second receipt time value of the local system time of the slave network subscriber and stores the second receipt time value; reading out the second receipt time value by the master network subscriber; calculating a speed parameter of the local system time of the slave network subscriber, the master network subscriber using the first receipt time value and the second receipt time value; and transmitting the speed parameter to the slave network subscriber; wherein reading out of the first receipt time value is carried out by the master network subscriber by sending out a first read-out telegram, and wherein reading out of the second receipt time value is carried out by the master network subscriber by sending out a second read-out telegram.