Does Labview affect the system time?

[JonJay]

This is a generic question that our network administrator cannot figure out. We have recently upgraded our network and included a networked clock to synchronize all the clocks. All the other computers are doing fine with this but for some reason the 4 computers that have Labview on it (and only those 4 computers) have not been synchronizing with the network time. Is there any reason or way that Labview could be affecting the system time of the computers it is on or is this most likely a network based problem?

[smercurio_fc · Accepted solution]

I cannot think of a way that LabVIEW would be affecting time synchronization in a domain. I've never seen that issue here at work, and I have our domain server act as the time reference.

Installation of LabVIEW does install a "National Instrument Time Synchronization" service. It's possible that may be the cause of the problem, so you could try disabling it and see what happens. On my system the service is set to "Automatic", but it's not started.

[JÞB]

LabVIEW itself will not cause this problem- Period.

That being said, LabVIEW programs WILL often cause this problem on Windows machines.

 Since I probably sound like I've contradicted myself I'd better explain.  The Windows OS has a low-priority task that is responsible for updating the system clock.  Time servers typically run in the background as well (after all the PC would be no use to the user if the network or housekeeping processes demand all of the CPU resources)

Applications can be written in any language that demand a large portion of the CPU's resources (CPU Hogs, in the vernacular.) Writing a CPU Hog in LabVIEW is very easy.  In fact so easy that a good portion of the Style Guide is devoted to how to avoid writing a hog in LabVIEW.  See especially pgs 6-10 & 6-11 in the guide for details

[JonJay]

Smercuiro_fc hit it right on the dot. I disabled the "National Instrument Time Synchronization" service and it immediatly updated my system time to the correct time. Must just have a conflict of how the network administrator set up the domain time.

Thanks for pointing it out!

[JÞB]

So - I stand corrected! somewhat! "National Instrument Time Synchronization" service not LabVIEW

Instead of disabling the service you may what to find another solution.  If you ever try to write LabVIEW code that needs the "National Instrument Time Synchronization" service you just shot yourself in the foot! (and the poor guy trying to figure out WHY the code isn't working right and doesn't know you stopped the service may shoot you again)

Smerc, Any ideas on:

1. What NI tools rely on the Time service,  Is it mostly RIO FPGA, RT &/or HSDIO 
2. Work arounds that allow the service and the domain service to run without butting heads

Gotta love learning!

[smercurio_fc]

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Jeff Bohrer wrote: 

Smerc, Any ideas on:

1. What NI tools rely on the Time service,  Is it mostly RIO FPGA, RT &/or HSDIO 

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Don't really know for sure. I think Lookout and the DSC module.