Time Sync from PXIe8880 to PXI 6683H to IRIG-B or PTP

[Pesmith8]

Hi Group,

I have been working to time sync a new PXIe 8880 controller to a MasterClock GMR5000 grand master clock using both IRIG-B and/Or PTP.

In my case I am using Pharlap ETS (with LabVIEW 2013, Daqmx  16, NI Sync 16, Timesync 16)    Also setup a SSD disk for PXIe 8880 controller that is running NI Linux RT.

First my Pharlap experience.

What I have found it that it rather challenging to get Pharlap ETS to Sync the controller to the GMR5000 through the PXI 6683H.  The PXI 6683H will sync to the GMR5000 in Max by following the instructions at NI.   But to get in Max the Controller to sync to the 6683H has not worked yet.   Part of this difficulty is in my old version of LabVIEW and DAQmx, but that is the world I live in that cannot changed until a software in use is updated.

What has worked better was to run three shipping  labVIEW VI's that are rather hidden in Examples in

C:\Program Files (x86)\National Instruments\LabVIEW 2018\examples\instr\niSync\Time-Based

These are  in order of my execution.

1. C:\Program Files (x86)\National Instruments\LabVIEW 2018\examples\instr\niSync\Time-Based\Advanced\Set Time Reference.vi
2. C:\Program Files (x86)\National Instruments\LabVIEW 2018\examples\instr\niSync\Time-Based\Getting Started/Monitor Synchronization.vi
3. C:\Program Files (x86)\National Instruments\LabVIEW 2018\examples\instr\niSync\Time-Based\Advanced/Discipline PXI_Clk10 to Time Reference.vi

For me to get the time sync to actually work and give same time in max for controller to what the GMR5000 was at I made a labVIEW project and then made the project a RT project, with the PXIe 8880, and then copied the all the VI's that are in the /Time-Based path to this project.  Then when I executed the VI's listed in order, I was able to set the 6683H time source, then check its synchronization, and then the 3) would then set the PXIe 8880 to the time of the 6683H.

My work with NI Linux RT

Setup a second SSD for PXIe 8880 running Daqmx_2020, NI-Sync 2020, LabVIEW 2020

In max with this have no way to do any configuration in Max for PXI 6683 or to set the Controller time sync.  So ended up using the same VI's listed above.

Was able to get the time sync operational by using the same synchronization order. 

Questions

1. I wanted to check with the Group to see if my approach is correct or what would be recommended?
2. Is it a good approach to have in a separate loop the Monitoring of Sync running all the time on the PXIe 8880?    (I was not sure if this monitoring would interfere with the main task of syncing the controller)

My plans is to put the code in 1-3 into the code that will be running on PXIe 8880 on startup.   This should also allow monitoring of the time sync accuracy so that users can know that Controller is actually synced.

As always any guidance is appreciated.

Paul

[RVallieu]

I can't offer anything constructive, but I am interested the replies to this!

[Pesmith8]

Hi Ryan,

I realize that this is an old post, but wanted to mention  that time sync has been resolved.

The resolution was to move to using NI-Linux-RT.  In that OS, when are  using OS Version 20.5 have been able to make a very nice time sync using IRIG-B, where can monitor the sync quality between IRIG-B source, and the 6683H card, and the controller and the 6683H card. This process has been duplicated to three different chassis/controllers.

I have found that NI-Linux-RT is a big improvement over Pharlap (so long as have the higher core count controllers)

I found that Pharlap ETS was effectively impossible for NI to get working.

Paul

Wind Tunnels at WPAFB

[mcduff]

Quick Questions:

1. Did you do the same order of operations as described in the previous posts?
2. Lastly, did you output an IRIG-B source from the 6683H and input that into the controller to sync the RT clock?

Thanks

[Alisha_P]

Hey mcduff,

On Linux RT, the OS time should sync to the PXIe-6683 board clock by default, without additional steps. You can follow the instructions in the manual/help to synchronize the PXIe-6683 board to a clock of your choosing and the OS time will synchronize as well. This is different than the behavior on Windows/PharLap.

Just a note, most of these Sync Labs products no longer add value over what is available in the released NI-Sync product. I mention this because the topics covered in this post should be fully supported and could be addressed through other official support lines, as available.