Overview Of Instrument Drivers; Instrument Driver Types - Keithley 708B Reference Manual

Section 5: Remote commands

Overview of instrument drivers

To use an instrument connected to a computer, you need to send instrument commands to it to make
it do what you want. This can be tedious, as the programmer has to learn the low level syntax and
also deal with how their programming language or development environment interfaces to the remote
communication interface driver or VISA I/O library. Keithley and most other test and measurement
companies supply instrument drivers for their instruments.
One thing a driver can do is deal with cross-coupling issues. If you change a setting on an instrument,
this can cause other settings to change without notifying you. For example, if you change the range
on an instrument, the resolution can change at the same time. Instrument drivers take care of these
issues for you as long as it is feasible. Therefore, a driver would have a call where you pass in the
measurement function, range, and resolution. The driver would then take care of sending the correct
sequence of commands or generate an error if it was impossible to set the requested values.
For information on finding instrument drivers on the Keithley website, see
drivers (on page 5-20).

Instrument driver types

There are several different styles of instrument drivers. Keithley Instruments provides three different
instrument drivers for the Models 707B and 708B: a native LabVIEW driver, an IVI-C driver, and an
IVI-COM driver. You need to pick the style that best suits the application development environment
(ADE) that you are using. For example, if you are using LabVIEW, you would pick a native LabVIEW
driver. If a native LabVIEW driver is not available then you can use an IVI-C driver as LabVIEW has
the option of creating a wrapper for the IVI-C driver.
LabVIEW supports IVI-COM drivers but they are definitely not the first or second choice. However, if it
is the only driver type for the instrument, it can be used.
If LabWindows/CVI or C/C++ is your programming language, an IVI-C driver is the best option. For
VB6 and any .NET language (C#, VB.NET, and so on), an IVI-COM driver would be the best option.
Sometimes instrument vendors do not provide all three driver types. Most languages can
accommodate other driver types, but this is not optimal.
The following sections describe the different driver types in more detail.
5-18
Models 707B and 708B Switching Matrix Reference Manual
707B-901-01 Rev. A / August 2010
Obtaining instrument