Discussion:
Using USB-8451 using VISA (.NET) and MS/VB2005
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Cernek
2008-04-23 19:40:11 UTC
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I am familiar with communicating with GPIB instruments using MS/VB2005 and NI VISA (.NET). I recently purchased a USB-8451. MAX can see the device. I can't figure out how to communicate with it; what the protocols are. I looked at the 8451 Doc's, VISA Doc's, etc. All of the examples I can find talk about using LabView. Any examples using native VISA (.NET) calls to a USB device would be VERY helpful.
 
Regards, Cernek
MXI Master
2008-04-24 20:10:12 UTC
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Cernek,Currently there is no .NET support for NI-845x, though you can use Microsoft C/C++ in Visual Studio to get in the back door of a .NET project.&nbsp; VISA, on the other hand, is available in .NET so if you may attempt to make low level VISA calls.You can find the VISA examples for Windows 2000/XP here:<img src="Loading Image..."> And for Vista:<img src="Loading Image...">
Cernek
2008-04-25 23:40:05 UTC
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Hi Marshall, Thank You.
I can do the VISA .Net stuff from MS/VB2005 without difficulties, as witnessed by the attachment.
Note that one of the devices is "USB0::". How do I communicate with this device?
Regards.
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VISApic.JPG:
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MXI Master
2008-04-28 19:40:11 UTC
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Cernek, You can program the NI-841x device in Visual Studio in the C/C++ non-managed code environment. You can then either, have an un-managed project and have all your code in there. The other option it to create a DLL from this code and call it in your .NET project. You could also create this DLL in CVI/LabWindows or LabVIEW.
Cernek
2008-04-28 19:40:11 UTC
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Just to be clear, What I am hearing is that the ONLY ways to talk to the USB-8451 are 1) Use LabView on top of VISA or 2) use the libraries (*.lib, *.dll) that come on the accompanying CD. Specifically, I CANNOT use VISA .Net, directly, to talk to it.
Since LabView can talk to it, through VISA, why can't I be given the low-level protocols so that I can talk to it directly through VISA myself? Or, does LabView NOT use VISA to talk to it?
Regards, EdC
MXI Master
2008-04-29 17:40:14 UTC
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Pardon me if I was not clear earlier. NI-845x supports development in:1) LabVIEW2) LabWindows\CVI3)Microsoft C\C++Though it does utilize VISA, we do not publish what those commands are because the driver is highly complex. The best option for you seems to be to develop in one of the other development environments, and create a DLL to include in your .NET project. You can call the ni845x.dll C dll from inside .NET but it may not be trivial.
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