communication with USB Raw device

[kimhyun]

Hello, i was trying to establish communication with a USB raw device. While testing in Measurement & Automation eXplorer it's working properly. But when trying in labview, i was getting the following errror. I was giving *IDN? command to write buffer and trying read the response from VISA Read. Can anyone suggest me how to solve this problem.

[Andrey_Dmitriev]

Is your device IEEE 488.2 compliant?

Are you able to send *IDN? command from MAX?

 

[EvenDeejay]

You are reading too fast after the writing. Try the Basic Serial Read/Write example that ships with LabVIEW.

[Andrey_Dmitriev]

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@Even Deejay wrote:

You are reading too fast after the writing. Try the Basic Serial Read/Write example that ships with LabVIEW.

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What mean "too fast" from your point of view? There are no any requirements for delay between write and read I/O operations. You can read answer immeaditely after writing. In case if device will not able to deliver required data, then Timeout will occurred.

The correct example for USB RAW communication in this case is "USB RAW - Bulk.vi" (located in LabVIEW x.x\examples\instr\visa.llb)

[kimhyun]

Yes, i was getting response in MAX. I don,t know whether it is 488.2 compliant or not. I was using a Transcend pendrive

[Intaris]

Why on earth would a pendrive response to a *IDN? request?

[kimhyun]

I am getting response in VISA session of MAX. But while executing the VI I am getting The error.

[kimhyun]

Response from MAX....

[Dennis_Knutson]

Nonef of what you are doing is making any sense. You are certainly not getting any response in MAX. The simple fact that you managed to install a VISA driver for it is meaningless.  And where in the world did you get the idea that you would get a response from sending *IDN? to a pendrive? You just cannot make this stuff up. Why even bother with creating a USB RAW interface to a pen drive? Why would you want to override the windows driver for it?

[Andrey_Dmitriev]

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@Dennis_Knutson wrote:

Why even bother with creating a USB RAW interface to a pen drive? Why would you want to override the windows driver for it?

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That could be great exercise...