Status “NOT AVAILABLE” for IEEE 1588–2008 Time Protocol PTP on VxWorks cRIO

Updated Oct 7, 2019

Reported In


  • CompactRIO Controller


  • NI-TimeSync

Operating System

  • VxWorks

Issue Details

I installed NI-TimeSync on my VxWorks-based CompactRIO to enable the IEEE 1588-2008 Precision Time Protocol synchronization feature. The VxWorks device does not work in the new situation. When I open the Time Settings tab in NI MAX, the status is "NOT AVAILABLE" for Clock ID, State, Master Clock ID, and Grandmaster Clock ID. Also the time is not kept in sync.


VxWorks CompactRIOs can use different sources for time synchronization, e.g. PTP, SNTP and EtherCAT. If any other protocol has a higher priority than PTP, it is expected behavior that PTP does not acquire any data because it knows it is not being used.

The priority of the protocols can be configured in the [TIME SYNC] section of the main configuration file ni-rt.ini. The following tokens need to be present:
source.ptp.usable=True{<ID generated by your system>}

In case you edit this file, restart the cRIO to apply the new settings:

Additional Information

The token source_priority can have more than one protocol name assigned, e.g. source_priority=sntp;ptp;. The order determines the priority, only the first available source is used.