Custom Device: How to make USB Device run in RT-Target

[rajamodol]

Hi Board,

I am trying to create custom device for my Power Supply which is connected to PC (Host) via USB Port. The power supply device will be controlled with using SCPI languange.

My USB Device is acknowledged by MAX as: USB0::0x0403::0x6001::83556::RAW in "My System"

How can i make my USB Device work in RT-Environment/ Remote System ?  Will it work if i deploy the custom device with those address? 

Thank you for your help,

Rajamodol

[Texas_Diaz]

That means your device is seen as a USB RAW device by the system; that's a necessary first start - not all versions of LabVIEW Real-Time can see all USB devices as USB-RAW, but versions of LabVIEW Real-Time 2012 and newer should have a much better chance of doing so (thanks to improved USB support appearing in those versions).  

The general idea is summed up here:

http://digital.ni.com/public.nsf/allkb/E3A2C4FE42D7ED0D86256DB7005C65C9

Generally, you will have to write your own device driver using NI-VISA.  If the device is seen as a USB-RAW device, NI-VISA can be used to interact with the device even on an RT system.  Unfortunately, drivers written for Windows are NOT compatible, even on PXI (PharLap) based systems.

-Danny

[HoussamK]

Hi Raja.

your instrument is USB RAW, so NI VISA can still be used, but more information about how the instrument communicates is needed.

For any USB instrument, there are four different ways of communicating: Bulk, Control, Interrupt, and Isochronous, however, the NI-VISA driver only supports Bulk, Control, and Interrupt. In the National Instruments Example Finder, there are three examples of using USB RAW. Each explaining one of the three supported methods of communication.

[HoussamK]

Controlling an instrument is inherently non-deterministic, so LabVIEW Real-Time isn't generally used for this type of communication.

How Can I Use GPIB Instruments in My Real-Time Application?

concepts for using a GPIB instrument are described. These concepts should be the same for USB.