Hi Gabe,
This Sample Period Setting actually has no
affect on how fast or slow the data is acquired. 1 Sample on Demand
acquires data as fast as possible, taking a sample as soon as the
Processor has completed the previous one. This means that in actuality,
a sample is taken about once every 1-3 ms, depending upon the processor
speed and what is going on in the system.
The Sample
Period input simply allows you to assign a delta-t value for the
waveform datatype. This is an arbitrary value set by the user and does
not affect when samples are taken. It was meant as a way for users,
when acquiring with an external clock, to input the frequency of that
clock so that their data would be displayed on the chart correctly. What
this means is that the data you are acquiring is being taken
every few milliseconds, though the dataview x axis makes it look a lot
longer.
If you want to actually sample once every 60s, it would be better to
a. Use a finite or continuous acquisition task with an internal HW timed sample clock
b.
Continue to use 1 Sample On Demand but use the Execution Control Tab to
define a 60s delay before or after the step and leave the Sample
Period Input set to 60s. This means that the step will execute,
taking one sample, and then Signal Express will enter a delay that
lasts 60s, before executing the step again.
