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130 Agilent VISA User’s Guide
6
Programming via USB
Although the case of a VISA alias is preserved, case is ignored when the
alias is used in place of the full resource string in a
viOpen call. For
example,
UsbDevice1
,
usbdevice1
and
USBDEVICE1
all refer to
the same device.
Using the alias, a viOpen call would look something like this:
viOpen( . . ., "UsbDevice1", . . . );
As you can see, this is much simpler than having to use the full resource
string for a USB device.
Using the alias in a program also makes it more portable. For example,
two identical USB function generators have different resource strings
because they have different serial numbers. If these function generators
are used in two different test systems and you use the full resource string
to access the function generator in the test program, you cannot use that
same program for both test systems, since the function generators’ full
resource strings are different. By using the alias in the program,
however, you can use the same program in both test systems. All you
need to do is make sure the same alias is used for the function generator
in both systems.