Synchronize Phar Lap RT PXI to the NTP Time Server

Updated Oct 24, 2020



  • NI-TimeSync 17.0
  • NI-TimeSync 17.5
  • NI-TimeSync

Operating System

  • PharLap

I need to synchronize the Phar Lap RT PXI system time with an NTP time-server that is on the same network as the RT system. 

I would like to set the RT system time to that of the NTP time-server when the RT system starts up. 

I was hoping that installing NI-TimeSync on the RT system would achieve that, but it did not. 

Download and install on your PC the following: Note: SNTP Plugin not found on later versions of NI-TimeSync than NI-TimeSync 1.2.

Next, add/install the following software to the RT PXI:
  • NI-TimeSync 17.1 or later 
  • NI-TimeSync Plugin for SNTP 1.2
  • NI-TimeSync Time Reference for IEEE 1588

In order to install the NI-TimeSync Plugin for SNTP 1.2, you would need to download and install NI-TimeSync 1.2 (as mentioned above). 

At this point you should be able to configure the SNTP sync from NI MAX. Make sure that SNTP is Enabled, maybe Disable PTP (if PTP is installed too).

The last step that you would need to do is to change the NI-RT.INI and ni-timesync-sntp.ini files from the RT. 
To access them, you would need to open File Explorer and search for:, where is the IP address of your RT PXI. 

Add to the NI-RT.INI:
source_priority = sntp;rtc;
source.sntp.enable = True
source.sntp.address = 
Where is the NTP server IP address in this case. 

Add to the ni-timesync-sntp.ini:

Where is again the NTP server IP address in this case.

Important Note: Do not change anything else in the INI files. 

Additional Information

For details about adding/removing software from a real-time target, please see Installing Software on Your Real-Time (RT) PXI Controller .