Does MAX Show the NTP Time or the Internal Real-Time Clock of My cRIO?

Updated Oct 3, 2018

Reported In

Hardware

  • cRIO-9082

Driver

  • NI-TimeSync

Issue Details

I have synchronized my cRIO-9082 with an NTP time server, but I am unsure how to tell if it is actually working. Is the time shown in MAX the internal real-time clock of my cRIO-9082 or the synchronized NTP time?

Solution

Once the cRIO has booted, with the settings to synchronize to an NTP server, the following occurs:
  1. The system clock of the cRIO-9082 is synchronized with the internal real-time clock. The internal real-time clock is maintained when the cRIO is even powered off. Since this synchronization happens on boot, the system time that is reported in MAX is from the cRIO onboard real-time clock time.
  2. After the cRIO is fully through the boot process, it sends an NTP request to the server to get the NTP time.
  3. The cRIO receives a response from the NTP server, synchronizes the system time and the process repeats at the interval specified in the .ini file. This does not reset the real-time onboard clock permanently. 
  4. Once the cRIO has gone through all of these steps (wait 5 minutes to be sure), you can refresh the connection in MAX (hit the refresh button). This polls the cRIO for its information again, and MAX will display the most recent system time, which at this point is synchronized to the NTP time.