Make First Sample Timestamp Property Writable

[mcduff]

The DAQmx API is extremely useful; one especially useful part of the API is the automatic logging feature. This part of the API is efficient, easy to set-up, and largely bug free, well-done NI.

One problem with the automatic logging feature is the value of the t0. This value is determined by the system clock, which is the clock onboard the controller. A lot of PXI systems have the ability to use GPS modules or other timing modules. It would be good to use this clock instead.

In NI-Sync we can create an event at a specific time and use this to trigger the DAQmx data acquisition. It would be nice to use this "event time" instead of the system clock. There is a property in the DAQmx Timing Property Node, under Advanced, called First Sample Timestamp:Value Property. However, this property is read only, please change it to writable also. In this case we can then write an exact GPS time start to the data acquisition.

Below is one simple use case of the property node.

mcduff

[roger1922]

Sounds a useful feature.  Why not?

Roger.

[crossrulz]

Maybe more useful would be a timestamp source property.  Then you could have it based on a GPS module or some other clock source.  Though, more useful would be a way to have the system clock sync to the GPS module.

[mcduff]

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Maybe more useful would be a timestamp source property. Then you could have it based on a GPS module or some other clock source. Though, more useful would be a way to have the system clock sync to the GPS module.

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Trying to change the system clock requires Admin privileges on Windows, along with a dialog confirmation. But I agree it would be nice to be able to do that. Maybe NI can add some sort of configuration for MAX that allows that. The only other idea I have is to create events based on a GPS clock, like an alarm clock.

mcduff

[crossrulz]

What I have started doing is using a GPS Time Server and setup Windows to synchronize to it.  It is a one-time setting ("Internet Time") and you are always good from there.  This is where I am getting that I wish NI's modules could be used to simply synchronize Windows time to the GPS time.