NI-VISA USB Specific Attributes in LabVIEW Property Nodes

Updated Apr 26, 2023

Reported In

Driver

  • NI-VISA

Issue Details

I am looking for attributes specific to USB Raw instruments. I wire a VISA control reference to the property node, which gives me access to the VISA properties. I can see some USB properties, but not the attributes for NI-VISA's USB Raw mode. How can I access these attributes?

Solution

A VISA resource is modeled as a class with certain attributes and methods. All resource classes inherit from the base the INSTR class, which has all the common attributes. Each specific resource type (such as GPIB, Serial, and USB) represents a sub-class that adds attributes and methods to the base class. 

A VISA control in LabVIEW can be configured to represent the different VISA classes. By default, the VISA control is configured to represent the base INSTR class. The property node shows the attributes that apply to that class of VISA resource. To avoid confusion with the USBTMC attributes, the USB Raw mode attributes are not shown unless the VISA control is explicitly configured for the specific USB Raw mode class. 

To make these attributes visible, right-click on the VISA resource control and go to Select VISA Class»VISA»I/O Session»USB Raw. The USB Raw attributes should now show up on the property node.