The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 08, 2025
Filed:
Mar. 30, 2022
Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US);
Yanbin Zhang, Shanghai, CN;
Xiaobo Peng, Shanghai, CN;
Sikai Zhang, Shanghai, CN;
Steven T. Seidlitz, Eagle, WI (US);
Arun K. Guru, Brookfield, WI (US);
Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US);
Abstract
To improve integrity of time synchronization, a node in a safety rated system verifies that its clock remains synchronized to another clock. Two adjacent, time-synchronized nodes transmit diagnostic messages to each other at an agreed upon interval and generate timestamps when the diagnostic message is received from the other node. The nodes then transmit their respective timestamp back to the sending node. Clock drift is detected by comparing a difference between the two timestamps at which the messages were received against a threshold. To avoid accidental detection of clock drift, a difference in transmission delays between the two nodes is stored in a FIFO buffer. Each node monitors the average of the data in the FIFO buffer. If the average deviates from the target value by too great a value, then the node determines the values of the clocks have skewed beyond an acceptable range and generates a fault condition.