Large time error on cRIO

[OneOfTheDans]

I'm having trouble configuring the time on my NI-9057 chassis. It's 4 minutes fast and if I manually correct the time through NI MAX, the cRIO aggressively re-syncs to the wrong time.

The cRIO has NI-TimeSync Time Reference for IEEE 802.1AS-2011 20.0.0 installed. I haven't found anywhere in NI MAX, over SSH, or through the browser to configure this module.

One of the many KBs I looked at suggested running this example program to check if NI-Sync is working. But the VI doesn't do anything; the Synchronization Monitor stays blank even when the VI is running (and no errors).

Does anyone know how to correctly set the time on a cRIO?

[Zaacha]

Hello OneOfTheDans,

I just had the same problem. After I went into the time settings and adjusted the date and time. I restarted the cRIO and it updated to the correct time.

I am sure you already found this solution but if not I hope this helps.

Have a great day,

[D_mitriy]

You are not alone, there are a lot of people struggling with Linux based cRIOs and time synchronisation. I spent about 3 or 4 weeks with NI support trying to get accurate synchronisation with the PC or network (via NTP). It turns out that not only does NI-Sync not work properly* with the Linux cRIOs, it also prevents the normal Linux NTP features from working.

Cherry on the top is that due to a bug #2866609, you can't use the DAQmx without NI-Sync installed on the cRIO, so, at least until this bug is resolved, you can't really synchronize time on the cRIO automatically. With Ni-Sync disabled, I achieved the sync accuracy under 2 milliseconds with the local network NTP server. But since I need DAQmx, I have no other choice than "happily" live with the up to 8 seconds** time offsets.

Notes:

* Unless you have a real TSN hardware in your network, your switches and routers will support TSN and so on and so forth. This is often not the case and is expensive. Other Linux-based cRIOs can't do that job, because to switch on TSN they need NI-Sync, and with NI-Sync enabled you can't sync them with anything else, except other TSN devices.

** That's what I measured on my system. The interesting thing is that the time reported by a "niSync Get Time" that I used in my code and other means of time measurement could be quite large and change over time. So, to be honest, I do not know how to reliably set and measure time on the Linux-based cRIOs.