The on demand acquisition mode configures a task to read samples one at
a time using software timing, finite acquires a predetermined number of
samples using hardware timing, and continous acquires an unlimited
number of samples also using hardware timing.
The rate control only applies to finite and continous tasks, and it
indicates how many samples per second are to be acquired. The "#
of points to read' is how many total samples in a finite acquisition,
or how many samples per read (per update of the test panel graph).
Unless your hardware is capable of measuring current directly using an
internal shunt resistor, you will need to wire an external shunt
resistor before making current measurements. The current input
task then uses the value you provide as the external shunt resistance
to convert the voltage read from the device into a current. The
value of the shunt resistance should be chosen such that the amount of
power consumed is reasonably low, yet still produces a large enough
voltage to be sensed by the DAQ device.
The device test panels are intended to verify device configuration and
external connections, so they do not provide for the application of an
external shunt resistor. However, you may use open a test panel
from the analog current input task and the correct scaled measurement
can be viewed from there.
I hope this answers most of your questions. If not, please reply back.
Jason
