Appendix C: Communication interface
Model 2110 5½ Digit Multimeter Reference Manual
C-12
2110-901-01 Rev. C/August 2013
VXIPnP drivers
VXI (Vixie) plug-and-play (VXIPnP) style drivers are Win32 DLLs that have some standard functions
defined by the VXIPnP Alliance, such as:
•
init
•
close
•
error_message
•
reset
•
self_test
•
Read
•
Initiate
•
Fetch
•
Abort
The application programming interface (API) was defined so that users of instruments would have a
familiar API from instrument to instrument. There are some basic guidelines when creating APIs for
your instrument, such as using VISA data types and how to construct the CVI hierarchy.
LabVIEW drivers
Native LabVIEW drivers
A native LabVIEW
TM
driver is a LabVIEW driver that is created using entirely built-in LabVIEW VIs —
it does not make any calls to external DLLs or Library files. This makes the driver portable to all the
platforms and operating systems that LabVIEW and VISA supports (currently, Linux
®
on x86, Mac
OS
®
X, and Microsoft
®
Windows
®
).
National Instruments (NI
TM
) maintains a native
(
http://zone.ni.com/devzone/cda/tut/p/id/3271
).
LabVIEW driver wrappers
All IVI-C drivers have a function panel file (.fp) that shows a hierarchy of the function calls into a DLL.
It is a tool that guides a user to select the correct function call in the driver, since a DLL only has a flat
API entry point scheme (unlike COM or .NET). Any CVI-generated .fp file can be imported into
LabVIEW and LabVIEW will generate a wrapper for the DLL. The drawback here is that the driver is
dependent on the DLL, which is not portable and is therefore Windows-specific.
Obtaining instrument drivers
To see what drivers are available for your instrument:
1. Go to the
Keithley Instruments support website
http://www.keithley.com/support
).
2. Enter the model number of your instrument.
3. Select Software Driver from the list.
For LabVIEW
TM
, you can also go to National Instrument's website and search their instrument driver
database.