Well, your problem is either with the settings of
the DAQ Assistant, or with any indicators you've created to see your
results. First, look at the Indicator, either in the Front Panel, or
BLock diagram: Right-click it and have a look at the properties. Now,
I'm not sure whatkind of indicator you've got without any sample of
your code, but assuming it's a graph of some sort, I think somewhere
you'll see a Tab called "Scale?" Have a look there and check to see if
the offset on multiplier for either the x or y axis is an incorrect
value for you. In a couple instances, I have seen the multiplier
change for me, so if that's the case for you, create a property node
for the indicator (Right-click and "Create Property Node"), select the
X and/or Y multiplier/offset values, and place a control or constant to
set the value. You can stick the Property node anywhere, but I'd put
it on the left-hand side somewhere at the "start" of the code in the
Block Diagram, just because I tend to keep the "initialization" steps
there.
Now, I'm not too familiar with using the
Express VIs, so I am unsure if there are any input terminals on it once
you've set it up, but if there are, I'd say create constants or
controls for any input values you don't want changing on you. If the
Assistant has an input for a Task, then all you've got to do is crate
one to wire to it.
All you do is open up MAX, look at the panel
on the left for "Data Neighborhood," expand it with the plus sign,
Right-click on "NI-DAQmx tasks" and select "Create New NI-DAQmx Task."
There you go through [basically] the same dialog as you would for the
DAQ Assistant; picking the channels, the frequency and the number of
samples, etc. Set and save the settings you need, and label the task.
Now you've got your task settings saved and they shouldn't
spontaneously change on you; I notice that when the devices are not
connected or turned off, the DAQ Assistant goes "blank," so maybe it
resets to default values sometimes if you're turning off the devices,
or disconnecting? In LabVIEW, you can place the Task Constant in the
Block Diagram (Measurement I/O >> NI-DAQmx >> Task Const),
then use the drop down menu on the constant to select the name of the
task you created.
In case the DAQ Assistant doesn't
have an input for wiring your task to, I would suggest looking at some
examples found in the Example Finder to setup your program using the
NI-DAQmx VIs; the VIs in that NI-DAQmx category.
I hope that helps point you in the right direction.
Cheers,
Dan
