Configuring multiple IP addresses for SNTP or TimeSync on cRIO

[Chris_12345]

We are trying to build a cRIO data acquisition system with reliable access to a time server, so that if one time server fails, then another one is used instead. Unfortunately, configuration of SNTP or TimeSync on cRIO only allows one IP address to use for time synchronization.

A clumsy solution would be to have code that automatically edits the IP address in the ni-rt.ini file and then reboots the controller, but I am looking for something cleaner. Any ideas out there?

[Kevin_F]

Hey Chris,

Since a lot of the synchronization with the time server is done when the controller is first booted up I think the only way to accomplish what you are looking for is the solution you have already suggested which makes changes to the .ini file and then reboots the controller.  Please post back with any additional questions.

[johnsold]

Kevin,

I have not used cRIO, but will be doing so in the near future.  I have also not worked with time servers, so I may have misunderstood.  Something you said seems quite bothersome.

For systems which are expected to run for very long times (real time systems) an option to synchonize with a time server periodically, including a means to select an alternate server, should be standard.  Reboots should NOT be required if contact with a server is lost or the servers is deemed unreliable.  Obviously the program developer should have access to control when and how time synchronizations and server changes are implemented so any adjustments to the timestamps can be handled appropriately.

Can you point me to some documents which cover this topic?

Lynn

[Kevin_F]

Hey Lynn,

Currently the ability to select an alternative time server is not available in our products.  If you want you can create the product suggestion by going to www.ni.com/ideas and I will vote for the idea.  Currently if you lose connection with the SNTP time server your timestamps will then be synchronized with the real time clock on the motherboard.  These timestamps will not be synchronized with the time server but if you know when the server went down and when it came back on you can figure out what the actualy time stamps were based on the relative time stamps from the real time clock.  Please post back with any additional questions.

[Chris_12345]

Kevin and Lynn,

I have just posted the suggestion on the Idea Exchange:

http://forums.ni.com/t5/LabVIEW-Idea-Exchange/Configuring-multiple-IP-addresses-for-SNTP-or-TimeSync...

Chris

[johnsold]

Thanks,

Lynn