Instrument commands

[jayj]

I am new to inst. driver development,
I am developing an GPIB instrument driver,
and am wanting to know how the instruments commands
are actually set to the attributes.
Example: How is the instruments reset command *RST
set to an attribute, and how is it actually
called in a function?
I ran the IVI wizard, and it generated all the code,
but I am needing to add other functions to the driver,
to utilize other instrument commands.
Please advise...

[DiegoF]

Hi,

I think the best way to understand IVI drivers is looking at other driver for reference. You can look at the hp34401a IVI driver, for example, which includes all the source code.

For the particular example you mentioned, resetting the instrument, there isn't an attribute associated with it. The reset funcion get the io session and sends the *RTS command. Check the hp34401a_reset function.

When you have an attribute, such as range (HP34401A_ATTR_RANGE), you can associate a read and a write callback function. The callback function is called by the IVI engine every time you try to access the attribute. It is the callbacks that actually perform the instrument I/O.

Hope this helps.

DiegoF
National Instruments.