What Clocks Are Adjusted When My NI Controller is Running in IEEE 1588-2008?

Updated Sep 3, 2019

Reported In


  • CompactRIO Controller
  • CompactRIO Single-Board Controller
  • Industrial Controller
  • Current Input Device for FieldDAQ
  • Voltage Input Device for FieldDAQ
  • Temperature Input Device for FieldDAQ
  • CompactDAQ Controller

Issue Details

When my CompactRIO (cRIO), CompactDAQ (cDAQ), Industrial Controller (IC), or FieldDAQ is running in IEEE 1588-2008 mode, what clocks on the controller is being affected by the 1588 synchronization?


Depending on if the NI controller you are using is TSN synchronization enabled (1588 hardware capable) or without TSN synchronization enabled (1588 software capable), there are different clocks for different times in the system that will be synchronized to the 1588 network time.

Devices Without TSN Synchronization Enabled (1588 Software Capable Device)

Only the system time is synchronized to the 1588 network time.  The sample clock time (that controls the timebase and hardware sample acquisition), the hardware time (that drives the real-time clock), and the FPGA clock time (that controls the rate of FPGA processing) are not synchronized to the 1588 network time for devices without TSN synchronization enabled.

Devices with TSN Synchronization Enabled (1588 Hardware Capable Device)

In NI 1588 hardware capable devices, the system timesample clock timehardware time, and FPGA clock time are all synchronized to the 1588 network time.  The network interface card on the NI 1588 hardware capable device synchronizes the sample clock time, the hardware time, and the FPGA clock time.  The hardware time drives the system time.

Additional Information

802.1AS clock synchronization functions the same as 1588 hardware time synchronization in terms of how the different clock times on the NI controllers are affected.


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