Instrument Control (GPIB, Serial, VISA, IVI)

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LabVIEW says I have no DAQ hardware configured but it works with MAX

I'm using LabVIEW 6.1 and Measurement and Automation Explorer 3.0.2.3005 on Windows XP SP2, and I'm trying to communicate with some instruments through GPIB in LabVIEW. When I start LabVIEW and click on DAQ Solutions it says "You have no DAQ hardware currently configured." I click "Go to the NI-DAQ config utility" which launches MAX. In MAX, I can see my devices and communicate with them. Is there anything else I need to do to let LabVIEW know how they're configured? Can I use my GPIB devices in LabVIEW without first running DAQ Solutions?
 
One other thing that might be relevant: When I right click on Instrument0 in MAX and select "communicate with instrument", it waits for a while and then says "iberr = EBUS ... EBUS indicates that no devices were detected on the bus." I can then send it *idn? and it usually works anyway, but the string it returns from *idn? is slightly different each time. It's always NDCV+0.000009E+3 but the value before E+3 changes. The rest of my devices appear to work fine though.
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DAQ and GPIB are two completely different things. DAQ refers to NI DAQ boards. If you want to use an Express VI in LabVIEW for your GPIB instruments, you use the Instrument I/O Assistant. Better would be to see if there is an existing instrument driver. You can search for those at http://www.ni.com/devzone/idnet/default.htm .
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Well, my DAQ card is working, because I can use it to communicate over GPIB, so I don't know why LabVIEW keeps telling me that it isn't configured. I looked at that link to the instrument drivers, but couldn't find any drivers that work with my equipment for this version of LabVIEW. I also looked for a VI for my equipment but didn't find anything. Does this mean that I can't use LabVIEW with this equipment? About a month ago, I controlled some hardware over GPIB by writing C code, and it worked fine. I didn't need to download a driver -- I just used the functions from whatever header file shipped with MAX, and sent GPIB commands and everything worked.
 
So, if I can't find drivers for my GPIB instruments, is it not possible to use the instruments with LabVIEW? I have some more equipment sitting around that I can plug in, so maybe I can find something else that can do the job, and that has the appropriate drivers.
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You DO NOT HAVE A DAQ BOARD. You have a GPIB controller and that is not the same thing at all. If you ever buy one of NI's multifunction DAQ boards, then you will be able to use the DAQ Assistant and all of the functions associated with DAQ. In this world, DAQ has a very specific meaning and GPIB is treated much differently.

Of course you can use LabVIEW to communicate with your instruments. If there is no instrument driver, it just means you have to write the code yourself. The is the Instrument I/O Assistant as I already mentioned and there are all of the VISA commands. It's recomended that you use the VISA API instead of the lower level GPIB fucntions. You can even write your own driver with information on the other links of the page I provided. Also, even if there is no posted driver for your version of LabVIEW, that doesn't mean one doesn't exist or can't be made. Many people here have multiple versions of LabVIEW and it's possible to save for previous versions. If you find a driver and need it converted, download the driver (7.x preferably) and attatch it in a new post where you ask if someone can convert it for you.

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OK, you're right... I actually do have a DAQ card but it's not in this computer, and I don't need it for this project. I just finished another project where I was using the DAQ card so I still had that stuck in my head. Anyway, I'll look into using the Instrument I/O Assistant. Thanks for your help.
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Philbert,

Looking at your query, in particular the "NDCV+0.000009E+3" string returned by the instrument, I'd guess that you're trying to talk to a Keithley DMM, such as a KE195 or KE196.

These instruments only seem to implement a subset of IEE488 and won't respond to *IDN? queries like more compliant GPIB/IEE488 devices, thus MAX won't identify them. There are drivers from the Instruemt Driver Network on the NI site which work fine with the Keithley DMMs, allowing you to change function, range etc and get back data.

 

Hope this helps

regards

dave Langstaff

 

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