Addressing A Session; Closing A Session - Keysight N9320B Programmer's Manual

Programming Example
Programming in C using the VTL

Addressing a Session

board
VXI logical address
primary address
secondary address
INSTR

Closing a Session

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As seen in the previous section, the rsrcName parameter in the
viOpen function is used to identify a specific device. This parameter
is made up of the VTL interface name and the device address. The
interface name is determined when you run the VTL Configuration
Utility. This name is usually the interface type followed by a
number. The following table illustrates the format of the rsrcName
for the different interface types:
The following describes the parameters used above:
This optional parameter is used if you have more than one interface of the same type.
The default value for board is 0.
This is the logical address of the VXI instrument.
This is the primary address of the USB device.
This optional parameter is the secondary address of the USB device. If no secondary
address is specified, none is assumed.
This is an optional parameter that indicates that you are communicating with a
resource that is of type INSTR, meaning instrument.
The viClose function must be used to close each session. You can
close the specific device session, which will free all data structures
that had been allocated for the session. If you close the default
resource manager session, all sessions opened using that resource
manager will be closed.
Since system resources are also used when searching for resources
(viFindRsrc) or waiting for events (viWaitOnEvent), the viClose
function needs to be called to free up find lists and event contexts.