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My device is complete, how communicate with PC through Labview?

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h_king2000

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May 7, 2008, 6:10:07 AM5/7/08
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Hi everyone,
 
I have my device developed, it used Atmel91SAM7, usb ports.
At first i have successfully communicate it with PC through REALTERMINAL, now i want through the real USB prot to cmmunicate.
I have a Labview8.0 , i thought i should use the VISA, but the VISA component don't work as i wished,  the created Controller can't display the actuel Port.
Furthermore, how can the LV find my usb device, i have no drive for it, cause it's a new Product.
 
So, what i can do now?
 
Thanks a lot!
Jin 

Dennis Knutson

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May 7, 2008, 10:10:08 AM5/7/08
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I don't know what REALTERMINAL is but if it is similar to Hyperterminal and the USB ports show up in device manager as com ports, then you can use VISA. Look at the shipping examples for serial communication.
If your USB ports are not emulating a serial port, then you can create your own VISA driver. See <a href="http://zone.ni.com/devzone/cda/tut/p/id/4478" target="_blank">http://zone.ni.com/devzone/cda/tut/p/id/4478</a>&nbsp;for a starting point.

mathan

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May 7, 2008, 10:40:06 AM5/7/08
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That link helps in how to&nbsp;use devmgr.dll to list the USB devices attached to pc.
That's all.
That's a small starting point.
[Note: I like people pinpointing my mistakes.]
Thanks,
Mathan

uCer

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May 7, 2008, 2:10:08 PM5/7/08
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yes, u are right, i have successfuly programed, it runs, but one error, it seems can't continually recieve data, for example, from ...341, 342, 343, 344 then jump to 1001...every thousand like so. but it works in gear when use RealTern,&nbsp; the stucture please see Attachment.now, i know that at least i can through LV access my device, but my aim is using USB Port, but i don't have a&nbsp; USB vendor ID and product ID,&nbsp; how i&nbsp; can do that forward?Thanks very much!Jin


visa.jpg:
http://forums.ni.com/attachments/ni/170/321870/1/visa.jpg

Dennis Knutson

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May 7, 2008, 3:40:09 PM5/7/08
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Well, emulating an RS-232 port is a valid USB connection as far as I am concerned. I think all you would be giving up is some data transfer speed.At 40Hz, you don't need USB 2.0 speed.
If you are creating a commercial product, then you will need a <a href="http://www.usb.org/developers/vendor/" target="_blank">vendor id</a>. For a one-off and something used internally, you might be able to just make one up. When you eliminate the RS-232 emulation, you then have a couple of options. You can use the driver wizard and use the VISA USB RAW or you can create a driver in C/C++. There is a lot of help in other forums for creating C based drivers. I'm guessing that the vast majority of USB devices ship with this type of driver and not a VISA based one.
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