Back to results
US 7,689,687 B2Granted
Communication controller with automatic time stamping
AssigneeFisher-Rosemount Systems, Inc.
InventorsBrian A. Franchuk, Roger R. Benson
Life of this patent
Estimating the term…
Abstract
Devices in a process control system communicate by data messages over a communication medium segment. Each device includes a communication controller that automatically time stamps events associated with received and transmitted messages.
Claims23
A device for communicating over a communication medium, the device comprising:
- a medium attachment unit (MAU) for receiving and transmitting messages on the communication medium;
- a central processing unit (CPU) for processing data contained in messages received and creating data to be contained in messages to be transmitted;
- and
- a communication controller for interfacing between the MAU and the CPU, the communication controller producing event pulses corresponding to events associated with received and transmitted messages and automatically storing time stamp values in response to the event pulses, wherein the communication controller includes a first timer for providing a first time value and a second timer for providing a second time value of higher resolution than the first time value, wherein the first time value represents a sense of time of the device on the communication medium and the second time value represents an internal time of the device.
1 more element
A method of time stamping messages exchanged between devices over a network, the method comprising:
- transmitting and receiving messages over a network;
- generating a first timer value that changes at a first clock rate, wherein the first timer value represents a sense of time of a device on the network;
- producing event pulses corresponding to selected events associated with transmitted and received messages;
- generating a second timer value that changes at a second clock rate that is higher than the first clock rate, wherein the second timer value represents an internal time of the device;
- storing a first time stamp value representing the first timer value when one of the event pulses is produced;
- and
- storing a second time stamp value representing the second timer value when one of the event pulses is produced.
4 more elements
A method of time stamping messages transmitted and received by devices over a process control network, the method comprising:
- synchronizing in each device a first timer that provides a local internal sense of time with a second timer that provides a node sense of time on a segment of the network;
- producing event pulses when events associated with the messages occur;
- and
- transferring time stamp values corresponding to the local and node senses of time to snapshot registers when an event pulse occurs.
1 more element
Dependencies are inferred from the claim text.