Hes-so Valais
Menu

PTP - Precision Time Protocol

PTP - Precision Time Protocol

PTP is an internal research project on the IEEE Std 1588 - Precision Time Protocol. A diploma work with the same topic has been executed in 2012. While the diploma work concentrated on the two-stepsync_msg mechanism, the project PTP focused on the one-stepsync mechanism. In this case the timestamping is carried out bythe NS DP83640 Precision PHYTER. An FPGA is used to control the phyter. The HES-SO FPGARack Board holds a DP83640 connected to a Spartan-6 LX FPGA. During this project we used the XC6SLX100 variant. Furthermore the USB port on these boards is used in RS232 mode to send the collected timestamps to a computer and to access the phyter's registers. A dedicated RS232 terminal has been developed to capture the timestamps on the computer and store them in a CSV file. This tool is written with C++/Qt.

A PTP node can be assigned to be master or slave. As master it sends a Sync message on the Ethernet interface every second. Upon reception of a Delay_Request a Delay_Response is returned. A slave sends a Delay_Request every time a Sync message is received. When the Delay_Response arrives, all collected timestamps are sent out via RS232.