Reading UTC Time from a cDAQ Using NI-Sync

Updated May 19, 2026

Reported In

Hardware

  • cDAQ-9187

Software

  • LabVIEW

Driver

  • NI-Sync

Issue Details

I am having an issue getting my cDAQ to report UTC time. In the announcement messages, I can see that my third-party grandmaster, synced to the cDAQ, sends the UTC offset (37 seconds). However, the NI hardware does not apply this offset and reports a time that is 37 seconds ahead of UTC, which matches with TAI. When creating a simple VI to read the Timing:UTC Offset and Timing:UTC Offset Valid NI-Sync properties, they return values 0 and False respectively.

Solution

It is not possible to read UTC time using cDAQ devices through the NI-Sync driver because they only support International Atomic Time (TAI). There is currently no way to configure these devices to operate using UTC instead of TAI. To obtain UTC, you must programmatically subtract the leap second offset from the reported time (currently 37 seconds) to match UTC.