kusb 488 and LABVIEW

[chravikumar]

Can any one tell me how to establish a connection with an instrument using the KUSB-488A USB to GPIB converter and LABVIEW?
My question is that if we have a GPIB card installed on computer LABVIEW will recognize and show the cards address..When i connect the USB-GPIB converter no such interface is shown. So how we address the instrument? using VISA? please give a simple example..

Thanks

[Dennis_Knutson]

Who makes the kusb-488A? Generally speaking, you usually cannot use the low level GPIB function in LabVIEW with a controller from a different vendor. Those functions are written to interface to the NI-488 driver which is designed to work only with NI boards. Some vendors claim to provide a driver that is 100% compatible with NI's and if true, you may be able to use the LabVIEW GPIB functions. Other vendors provide a replacement driver and a new set of GPIB functions. Other vendors, such as Agilent, provide VISA support for their board and you can use the LabVIEW VISA functions. I would check with the vendor of the kusb-488 to see what kind of LabVIEW support they offer.

[Rikud]

Make sure you have uninstalled the NI-488.2 driver. Then install the Keithley KUSB-488A driver (must be version 8.2 or higher).

The driver does give you NI Compatibility for use with LabView or LabWindows/CVI, etc. The driver will install a KEVICec Visa Passport. Make sure when communicating using Visa that you turn off the NI Visa Passport. You should then be able to communicate to instruments in LabView with the KUSB using either GPIB Read/Write or Visa Read/Write commands.

You can also see the KUSB and any connected instruments in the Visa Interactive Control utility. (Note: the KUSB will not appear in the NI Measurement & Automation Explorer

[chravikumar]

hello dennis and rikud,

KUSB is provided keithley..

I would like to state my problem more clearly...

I not only want to control keithley instrument but also instruments from other comapnies..
These instruments are connected through GPIB cables to the keithley intstrument which is finally connected to PC via USB-GPIB converter.

Now i have to send some command to and instrument (address 12).
I know that i should use Keithley's 488.2 driver to write to the USB..
My problem is where is this function..
IS it this one...

Instrument I/O->VISA-> write ???

If so wat is the format of addressing the instrument..In case of GPIB i know its GPIB0::address::INSTR  
i  want to know wats the format here..any suggesstions please...

Thanks

[Dennis_Knutson · Accepted solution]

Let me first try to explain the relationship with VISA and GPIB. VISA is a high level API (application program interface) that is able to be used with GPIB, serial, Etherenet, pci, USB, etc. You use a VISA Resource Name to define the physical interface. In the case of GPIB, it is of the format GPIBx::INSTR::address. The format of the VISA Resource Name does not change if you have a Keithley, NI, Agilent, etc. GPIB controller.

It is the VISA driver that will then in turn, call the lower level 488.2 driver. If the Keithley software is installed correctly and you have done the configuration of the passport, then all you have to do is use the VISA functions on the palette you mention.

[Rikud]

Yes if you are using VISA for communication, use the Instrument I/O ->VISA->Write or Read, etc. type functions. As this device handles the conversion to USB, the VISA Resource Name will still be a GPIB format resource (e.g. GPIB0::12::INSTR, for a device at GPIB address 12, using the GPIB0 card).

If you are still not talking to your device, test the connection using the CEC diagnostic: Start->All Programs->CEC488->TRTEST.exe (use the Send and Enter buttons to test writing and reading respectively).

If you have the NI Visa Interactive Control on your system (Start->All Programs->National Instruments->VISA->Visa Interactive Control) you could also open this and see if your instrument is listed on the VISA I/O tab. If your device is not listed, then it would be good to check the   VISA Passports.

To check the VISA Paassports, open the NI Measurement & Automation (NI Max) utility and click on Software->NI-VISA, go to the VISA-Options tab, click on Passports and ensure the NI-VISA Passport for GPIB is marked off and the KEVICec Visa Passport for GPIB is marked on.

[chravikumar]

Hello rikud,

I tested my connection with trtest 488.2. It was successful.
Then i tried placing a visa write and a visa read in a program to just identify the instruments, but was not successful. Can you tell me the exact procedure. Is there a need to open a visa session to each instrument?? It would be great if u can design a simple VI for identifying an instrument with  VISA write and read.

Thanks and regards
Ravi Kumar

[Dennis_Knutson]

It is not absolutely necessary to do a VISA Open first but it is recomended. So a basic program would look like the code below. If it does not work, you need to provide more details, such as any error codes that are generated.

Message Edited by Dennis Knutson on 07-29-2007 08:29 PM

[Nek]

I was looking for KUSB and NI compatibility with the version 2.2.5 drivers and found this thread.  The KUSB is sold by Keithley but the hardware inside says National Instruments and the Keithley Version 9 drivers say QISI .  From what I can tell this looks like a National Instruments company since the dirvers, xml configuration files contain references to "NI" and the MSI files have many references to National Instruments. 

[chris_amadasun]

Hello Nek,
I am not sure if you have a question about using the Keithley instrument in LabVIEW.

NI-VISA and NI 488.2 are  products of National Instruments.

Please contact Keithley for support for KUSB.


Message Edited by Support on 03-27-2008 02:24 PM