Programming instructions

© National Instruments Corporation 29-1 LabVIEW Data Acquisition Basics Manual
29
Debugging Techniques
Is your VI not working as you expected? This chapter shows you some tips
to help figure out why your VI is not working. First, find your
LabVIEW
User Manual
because this manual is referenced in this section. With
LabVIEW data acquisition (DAQ) applications, you might find errors in
hardware connections, software configuration, or VI construction. The goal
of this chapter is to help you narrow down where the problem is in your
program flow.
Hardware Connection Errors
When no error occurs, but the data is not what you expected, then you
may want to check your hardware connections and jumper settings.
For example, if you have an analog input application, make sure your
signals are properly grounded. For more information on analog input
configuration issues, refer to Chapter 5, Things You Should Know
about Analog Input.
For SCXI modules, you must verify that gain jumpers are set up properly.
To verify how a DAQ device gets set to a certain gain (or limit setting
as noted in the software), refer to Chapter 3, Basic LabVIEW Data
Acquisition Concepts. Another common SCXI hardware error is using
digital lines on your DAQ device that are reserved for communication
with the SCXI modules.
In order to test that your hardware has not been damaged, connect a
known voltage to the channels you are using. To check the location of
any hardware connections, refer to your hardware user manual.