USB in Labview 6

[DrTrey]

I am looking for someone who has made Labview 6i work with a USB device. I am building a USB device and I have Labview 6 on hand and hate to buy the upgrade. Can anyone help?

DrTrey

[hooovahh]

Wow I don't think I can help but could you clarify a little please.

QUOTE

I am looking for someone who has made Labview 6i work with a USB device.

Do you mean, have LabVIEW interact with a USB device? What kind of USB device, USB camera, NI-USB DAQ device? USB thumb drive?

Do you mean running LabVIEW from the USB drive? Do you mean as a development system? Do you mean running a LabVIEW executable? Do I ask too many questions?

[Rolf Kalbermatter]

QUOTE (DrTrey @ Jun 30 2008, 04:41 PM)

I am looking for someone who has made Labview 6i work with a USB device. I am building a USB device and I have Labview 6 on hand and hate to buy the upgrade. Can anyone help?

DrTrey

You give indeed to little information about the type of device and such. If it is some DAQ device or similar however the standard mode of operation is to write a device driver and the according user space DLL wrapper. That can be easily imported into LabVIEW through the call Library Node in a way that is completely independant of the LabVIEW version.

Other means would be to use libusb to control your device. Interfacing LabVIEW to libusb through the Call Library Node is about the same in terms of version dependance but the libusb API is not really meant to be interfaced by high level applications like LabVIEW or VB and you will run in some issues that are usually most easily solved by writing a wrapper DLL that translates between the low level API and the LabVIEW Call library Node.

Last but not least there is USB Raw device support in NI-VISA. Not sure though from which version of LabVIEW this VISA feature is properly supported. While the feature is completely implemented in VISA, LabVIEW needs to support some extra API access modes to use this feature. A quick look in LabVIEW 6.0 shows that the necessary Nodes to use USB through VISA are not present. LabVIEW 6.1 is the first to support this interface but you will need a recent version of VISA installed on your computer. The first VISA versions had lot's of difficulties supporting USB device RAW access.

Princiapially option 1 will require you to really write C code. The other two options won't but can't be really considered a lot easier. You will simply implement the bit level protocol of your USB device in LabVIEW itself. Option two will still require some serious C knowledge to be able to properly interface to libusb through the Call Library Node. From that perspective using VISA to control your USB device would be probably the simplest solution but don't expect it to be trivial. One disadvantage of the two last options will be that you can't really leverage off that solution for non-LabVIEW users such as Visual Basic, Visual C, etc.

Rolf Kalbermatter

[LAVA 1.0 Content]

QUOTE (rolfk @ Jul 14 2008, 01:53 PM)

You give indeed to little information about the type of device and such. If it is some DAQ device or similar however the standard mode of operation is to write a device driver and the according user space DLL wrapper. That can be easily imported into LabVIEW through the call Library Node in a way that is completely independant of the LabVIEW version.

Other means would be to use libusb to control your device. Interfacing LabVIEW to libusb through the Call Library Node is about the same in terms of version dependance but the libusb API is not really meant to be interfaced by high level applications like LabVIEW or VB and you will run in some issues that are usually most easily solved by writing a wrapper DLL that translates between the low level API and the LabVIEW Call library Node.

Last but not least there is USB Raw device support in NI-VISA. Not sure though from which version of LabVIEW this VISA feature is properly supported. While the feature is completely implemented in VISA, LabVIEW needs to support some extra API access modes to use this feature. A quick look in LabVIEW 6.0 shows that the necessary Nodes to use USB through VISA are not present. LabVIEW 6.1 is the first to support this interface but you will need a recent version of VISA installed on your computer. The first VISA versions had lot's of difficulties supporting USB device RAW access.

Princiapially option 1 will require you to really write C code. The other two options won't but can't be really considered a lot easier. You will simply implement the bit level protocol of your USB device in LabVIEW itself. Option two will still require some serious C knowledge to be able to properly interface to libusb through the Call Library Node. From that perspective using VISA to control your USB device would be probably the simplest solution but don't expect it to be trivial. One disadvantage of the two last options will be that you can't really leverage off that solution for non-LabVIEW users such as Visual Basic, Visual C, etc.

Rolf Kalbermatter

Excellent reply Rolf!

I had to reply because I justhttp://forums.ni.com/ni/board/message?board.id=170&thread.id=340676&jump=true' target="_blank">read this Nugget (on the Dark-Side) by Shane where he introduces us to using VISA to interact with USB devices. I would have remained silent if the timing was not what it was.

Ben