Configuring IEEE 1588 Domain Number on NI Linux Real-Time Controllers

This article explains how to modify the Domain Number property when using IEEE 1588 (Precision Time Protocol) on supported NI Linux Real-Time (RT) controllers.  The Domain Number is a numeric value (0-127) that defines a logical grouping of PTP devices. Devices within the same domain synchronize with each other, while controllers in different domains ignore each other's timing messages.

To execute the steps described in this document, ensure your controller has the NI-Sync driver 19.0 or above installed, and that your controller is actually compatible with the IEEE 1588 protocol. This information can be confirmed in your device's user manual.   

1. Access the shell on your RT controller. 
2. Navigate to the following directory, using the cd command:

cd /usr/lib/x86_64-linux-gnu/ni-timesync/timereferences 

3. Running the vi command, open the ptp.conf file:

vi ptp.conf

4. In the text editor, use the arrow keys to navigate to the ;ptpengine:domain=0 line. 

5.  Press <I> to edit the file. Remove the leading semicolon to uncomment the ptpenginge:domain property and assign the desired value. Please note that the minimum value for this property is "0" and the maximum is "127"

6. Press <Esc> to return to command mode, then type :wq and press <Enter> to save the file and exit the editor. 
7. Reboot your controller to apply the changes.