37
Programming Example
Programming in C using the VTL
Next, you open a session with a specific device with the
viOpen function. This function uses the session returned
from viOpenDefaultRM and returns its own session to
identify the device session. The following shows the function
syntax:
viOpenDefaultRM (sesn);
viOpen (sesn, rsrcName, accessMode, timeout, vi);
The session returned from viOpenDefaultRM must be used
in the sesn parameter of the viOpen function. The viOpen
function then uses that session and the device address
specified in the (resource name) parameter to open a device
session. The vi parameter in viOpen returns a session
identifier that can be used with other VTL functions.
Your program may have several sessions open at the same
time by creating multiple session identifiers by calling the
viOpen function multiple times.
The following summarizes the parameters in the previous
function calls:
sesn
This is a session returned from the viOpenDefaultRM function
that identifies the resource manager session.
rsrcName
This is a unique symbolic name of the device (device address).
accessMode
This parameter is not used for VTL. Use VI_NULL.
timeout
This parameter is not used for VTL. Use VI_NULL.
vi
This is a pointer to the session identifier for this particular device
session. This pointer will be used to identify this device session
when using other VTL functions.
To Next Page
Loading...
Need help?
General
