Experiment Start timestamp

[David McFarlane]

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That said, here is my take...

Hmm, you no doubt already know that SessionTime in the .edat file 
records the clock time for the start of the experiment, but I suspect 
you want something that records the clock time down the millisecond, 
whereas SessionTime goes only to the second.  That will be a tall 
order, because typically Windows does not keep clock time down to ms 
resolution, E-Prime only gets that by interposing DirectX 
commands.  E.g., you could use the Time$ function, but that goes down 
only to seconds (and is what SessionTime already uses anyway, as you 
can see by reading the generated E-Run code).

You might instead use some common signal to start both your EP 
experiment and your external device at the same time, and then count 
from there.  Or you might program your EP experiment to delay until 
the clock time reaches some round value, although once again I would 
not expect that to be accurate down to the millisecond.

-- David McFarlane, Professional Faultfinder


At 1/29/2011 12:59 PM Saturday, EC wrote:
>Hello everyone,
>in the experiment data, OnsetTime and all the other Time Audit
>variables are measured in milliseconds since the experiment started.
>Is there way to know when the experiment started in "computer time",
>that is - a timestamp (in milliseconds) of the system clock at the
>start?
>In other words, when "Clock.Read = 0" happened? :)
>I ask because I have an external device which has a clock synchronized
>to the computer clock and I would to be able to combine data from the
>external device with E-prime data.

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