System Clock Update Time in Real-Time Hardware

Updated Nov 17, 2022

Reported In


  • CompactRIO Controller
  • PXI Controller
  • myRIO Student Embedded Device
  • Backplane for Compact FieldPoint


  • LabVIEW Real-Time Module
  • LabWindows/CVI Real-Time Module

Issue Details

How does my Real-Time hardware update its system clock?


Real-Time Series PXI Controllers
  • The system clock is updated from the BIOS at boot. System time can be corrected by booting into the BIOS.
cRIO Controllers and myRIO series
  • There are different ways system clocks operate on cRIO and myRIO controllers. In general, the system clock of both are synchronized with the internal high-precision clock at startup (when power is supplied to the chassis). This synchronization provides a timestamp to the controller. Note that not all cRIOs and the myRIOs do not have a battery backup, so a loss in power will reset the clock. Please check the relevant user manual to see if your cRIO chassis has a battery backup.
[c]FieldPoint 20xx Series
  • The controller's system clock can be set by specifying a Time Server in the Network Settings Tab of your [c]FieldPoint 20xx.  The time server updates the system time of the FieldPoint controller at boot. 
  • If no Time Server is specified, the date and time can be set programmatically using the RT Set Date and

Additional Information

All of these controllers keep their current system using an internal crystal oscillator after it has been set.