US 12,235,674 B2
Time synchronization between a master and a slave in a network
Oliver Hoeftberger, Eggelsberg (AT); and Franz Profelt, Eggelsberg (AT)
Assigned to B&R INDUSTRIAL AUTOMATION GMBH, Eggelsberg (AT)
Filed by B&R INDUSTRIAL AUTOMATION GMBH, Eggelsberg (AT)
Filed on Jul. 18, 2023, as Appl. No. 18/223,281.
Claims priority of application No. A 50540/2022 (AT), filed on Jul. 19, 2022.
Prior Publication US 2024/0028067 A1, Jan. 25, 2024
Int. Cl. G06F 1/12 (2006.01); G06F 1/14 (2006.01)
CPC G06F 1/12 (2013.01) [G06F 1/14 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method for the time synchronization between at least one master and at least one slave in a network,
wherein the at least one master predefines a master time and sends at least one synchronization message with the master time via the network to the at least one slave,
wherein the at least one slave, on which a slave time is running, uses the synchronization message to adjust the slave time to the master time using synchronization, and
wherein the at least one slave is an interrupt-capable network device of the network and uses a timer, which accesses the slave time to generate at least one interrupt, which is repeated at a predefined cycle duration, at a respective trigger point in time that is synchronized with the slave time,
wherein, when a synchronization message arrives, a time offset between the master time and the slave time is determined in the slave,
wherein a time fraction of the time offset is determined, the time fraction corresponding to an integer multiple of the predefined cycle duration of the at least one interrupt,
wherein an interrupt offset is determined from the time fraction and the time offset;
wherein at least one time jump is carried out by a synchronization unit in the slave to correct the time offset;
wherein a first trigger point in time of the at least one interrupt following the at least one time jump is set in such a way that the first trigger point in time following the at least one time jump is offset by the predefined cycle duration in relation to the last trigger point in time prior to the at least one time jump;
and wherein a number of trigger points in time of the at least one interrupt which follow the at least one time jump is temporally shifted by an adaptation duration, the adaptation duration for each trigger point in time of the number of the trigger points in time following the at least one time jump being selected from a time range in such a way that the adaptation duration corresponds at most to the interrupt offset and at most to a predefined temporal deviation, and that the sum of all adaptation durations for the number of the trigger points in time following the at least one time jump corresponds to the interrupt offset, taking a predefined tolerance value into consideration.