Agilent Technologies USB/GPIB Interface Converter 82357A, Руководство пользователя

Страница: 38 / 70

38 Chapter 2
Using the 82357A
Modes of Operation
Multiple 82357A Operation
When two or more 82357As are attached to a system at the same time,
we define the mode as the
multiple mode of operation
. In multiple mode of
operation, each 82357A is “bound” to its related IO Configuration for that
Serial Number. This is a different mode of operation than the single mode of
operation in that the configuration is not reused if you replace an 82357A
with another 82357A.
As with single mode of operation, the first time an 82357A is attached to a
system (assuming the Agilent IO Libraries Suite is installed), the software
recognizes that an 82357A is attached. If Connection Expert is not running,
the software displays an
Agilent 82357A USB/GPIB Interface Detected
dialog
box that allows you to accept the current settings. If Connection Expert is
running, it automatically refreshes, displaying the 82357A as a USB/GPIB
interface in its tree view; you can then change the properties of the interface
in Connection Expert.
The VISA and SICL interface IDs, Logical Unit, and GPIB Address may be
viewed at any time in the
property pane
of the Connection Expert. (To view
this window, click the blue IO icon and then click
Agilent Connection Expert
.)
Then, if you plug in another 82357A (with a different Serial Number), the
new 82357A will automatically be assigned a unique VISA Interface ID, SICL
Interface ID, LU, and GPIB Address.
SRQ Operation
If your VISA/SICL application uses SRQ callbacks (
viEventHandler()
in VISA
or
ionsrq()
in SICL) and your callback does not service the SRQ in a timely
manner, your SRQ callback function may be called multiple times.
To avoid this possible situation, design your SRQ callback functions to
handle being called when an SRQ is no longer asserted on the GPIB bus.
NOTE
You can change the parameter values of the 82357A as required. See
“Changing Configuration Parameters” for details.
You can also convert from multiple mode of operation to single mode of
operation. See “Changing Modes of Operation” for details.