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Precision Time Protocol Software

Get up and running with both IEEE 1588 and IEEE 802.1AS Precision Time Protocol right away.

Bartky Network's Precision Time Protocol daemon offers the following features:

These features have gone through extensive testing using dual MPC8313E-RDB boards running both PTP and Ping traffic. On a Freescale MPC8313E-RDB board running eight Sync/Follow-up Messages per second, it will support a plus or minus 50 nanosecond offset from master more than 99.9% of the time. At 128 Sync/Follow-ups per seconds, the system will synchronize within 16 nanoseconds of the "grandmaster" system.

PTPV2D Daemon help file example:

# ptpv2d -?
Usage:  ptpv2d [OPTION]
-?                show this page

-c                run in command line (non-daemon) mode
-f FILE           send output to FILE
-d                display stats
-D                display stats in .csv format
-z                debug level (0=none or bit mask 1:basic, 2:verbose, 4:message)
-x                do not reset the clock if off by more than one second
-t                do not adjust the system clock
-a NUMBER,NUMBER  specify clock servo P and I attenuations
-w NUMBER         specify one way delay filter stiffness
-H                specify hardware clock period in nanoseconds
-A                specify base value for clock frequency adjustment
-R                remember adjust value for slave to master transition

-b NAME           bind PTP to network interface NAME
-u ADDRESS        also send uni-cast to ADDRESS
-2                run in PTP version 2 mode instead of version 1
-8                run in IEEE 802.1AS PTP Layer 2 mode instead of IP/UDP
-P                run Pdelay Req/Resp mechanism instead of Delay Resp/Req
-l NUMBER,NUMBER  specify inbound, outbound latency in nsec
-o NUMBER         specify current UTC offset
-e NUMBER         specify epoch NUMBER
-h                specify half epoch
-y NUMBER         specify sync interval in 2^NUMBER sec
-Y NUMBER         specify announce interval in 2^NUMBER sec
-m NUMBER         specify max number of foreign master records
-g                run as slave only
-p                make this a preferred clock
-s NUMBER         specify system clock stratum
-i NAME           specify system clock identifier
-v NUMBER         specify system clock allen variance
-n NAME           specify PTP subdomain name (not related to IP or DNS)
-k NUMBER,NUMBER  send a management message of key, record, then exit

Here is a diagram showing ptpv2d in action running on a Freescale MPC8313E with full hardware timestamping support. It shows a slave MPC8313E-RDB board quickly synchronizing to a grandmaster. The the slave is then intentionally disconnected from the grandmaster for 2 minutes and then reconnected. On the second time reconnecting to the grandmaster, the ptpv2d code has optional holdover running so it quickly resynchronizes with the grandmaster.

Click on the chart for a closer look:

ptpv2d_sync_chart (26K)

Here is a diagram showing ptpv2d in action in the same test run after the clock has stabilized. This chart shows the flexibility of the ptpv2d software in that the software is configurable to run on the MPC8313E PTP Hardware clock with user configurable reference frequency period. On the MPC8313E-RDB board, this can be set to as low as 8 nanoseconds. It also shows that the software ban be configured for multiple sync/follow-up messages per second so you can trade off between clock accuracy and network load.

Click on the chart for a closer look:

ptpv2d_sync_chart (26K)

To help get your PTP project started, Bartky Networks can provide free of charge a binary load image for the MPC8313E-RDB board that will run for four hours and then terminate. This will allow you a low risk option to try before you buy as you can order the MPC8313E-RDB board directly from Freescale for only $299. This means you can actually build and setup a full hardware timestamping capable test environment with two Freescale boards running ptpv2d (e.g. one grandmaster and one slave) for around $600.

For more information on how Bartky Networks can help you with your PTP Embedded Linux or Data communications project, out contact information is here.

Web pages and associated content Copyright (c) 2007-2008 by Alan K. Bartky, all rights reserved