Can cRIO controllers be configured to accept more than one SNTP IP address?

[Chris_12345]

cRIO controllers can be configured to syncronize to SNTP servers by using the following snippet in ni-rt.ini:


    [TIME SYNC]
    source_priority = sntp;rtc;
    source.sntp.enable = true
    source.sntp.address = 10.0.58.1
    source.sntp.interval = 60
    source.sntp.port = 123
    source.sntp.verbose = false
    source.sntp.log = false

    However, can more than one IP address be specified, in case one of them fails? I've tried using a semicolon delimited list, but it doesn't work.

    Also, I am wondering if the cRIO controller can be configured to accept SNTP broadcasts from a remote machine, instead of periodically sending out SNTP requests to a remote machine.  Can this be done?

    Thank you for your assistance,

    Chris

[charris · Accepted solution]

Chris:

Unfortunately, the ini file can only use one IP address to sync to the server. If you're looking for a method to fail over to a new address, your best bet is to alter the IP routing/port forwarding of whatever network hardware the RIO is connected to. Alternatively, it may be possible to programmatically switch ni-rt.ini files, but that would require that the controller restart.

The cRIO won't accept remote broadcasts, either. I believe the primary reason is that it's not as consistent (from a deterministic standpoint). The behavior and timing is more predictable when the controller uses a request/receive method, rather than waiting on a broadcast packet. The former option also requires less processor overhead.

I hope I've been able to shed at least a little light on your issue. Good luck!

[CyGa]

Hi Charris,

This post is a little bit old, but you may help me on my issue. A customer is asking for SNTP source redirection in cause of network failure.

So could you detail a bit more what you were advising in your previous post ? ("If you're looking for a method to fail over to a new address, your best bet is to alter the IP routing/port forwarding of whatever network hardware the RIO is connected to.")

I can't use the alternative solution (modify the ini file) because of the required reboot...

Thanks !

[Aldo_A]

Hi zyl7,

It sounds that much of the configuration for IP routing will be dependent on the hardware you are using for networking instead of the cRIO. When performing IP routing, one of the most important aspects to keep in mind is that the IP address of the cRIO remains the same while still keeping it in the same subnet. Changing these will lose connection to the host PC and require a restart which is out of the scope of your requirements. Is there a specific aspect of your application that you have questions on?