USB-6501 command set

[MarcVB]

Hello Jennifer,

Thanks for the info on OPC.

I do have an additional question. I did read today that DAQmx works with virtual channels and connects to MAX. I also saw that under MAX one can have remote systems and its resources. Is it thinkable to use MAX to setup a channel to a remote computer where the USB-6501 resides and to connect in this way. I assume that the USB-6501 will be seen by MAX ... correct?

Thanks, Marc

[Jennifer O]

Hi Marc,

Remote systems are generally used for FieldPoint or remote VISA sessions.  DAQmx is not supported in this way.  To use DAQmx remotely, you must create the Global Virtual Channel.  The Global Virtual Channel is then made available to the network through OPC.

Regards,

Jennifer O.

[MarcVB]

Jennifer,

Suppose I manage to control the USB 6501 via VISA USB RaW ... can I then access it remotely via LAN in a similar way as I can do that with GPIB instruments?

Thanks for the help, Marc

[Dennis_Knutson]

As mentioned by Malcolm more than a year ago and Jennifer a week ago, the USB RAW information is not published and it doesn't sound like NI is planning to publish it any time soon.

[J^T]

Dennis:

And, as mentioned by me and MarcVB, we could use that data in our applications.

--J^T

Message Edited by J^T on 12-04-2006 06:19 PM

[MarcVB]

Dennis,

My question was more substantial then that. I was saying : "suppose I manage to use VISA USB RAW to control the USB-6501 (without help of NI)" .. will I be automatiically be able to access the USB-6501 through LAN from a remote computer as one can do with GPIB instruments. This was the question.

Thanks, Marc

[Dennis_Knutson]

I understand perfectly the question but thought the whole question was moot since the USB RAW information is not available. Jennifer already said that remote access in MAX can be used for sharing VISA resources. I have the ability to do that with the USB instruments I'm using. The same is true of serial and GPIB instruments. If and when you get USB RAW programming information, you can do the same.

[schuetzm@gmx.net]

Is there anything new about this?

I cannot get the NI-DAQmx Base to work on Linux. The readDigPort example in nidaqmxbase/examples/dio always returns weird values (0xBF89EE18, 0xBFC7B9E8, 0xBFC15188, 0xBFA67FD8, 0xBF888DF8, ...). They do this even if the device is not connected to the PC ...

But even if it worked, I would not want to use it, because my program should be as independent and light-weight as possible, and it doesn't make any sense to use a library that together with its dependencies is more than 60M (!) big, when the same thing would be doable in a few KBs/lines of code using libusb, if only the protocol specs were made available.

[schuetzm@gmx.net]

OK, so I sat down and analyzed the protocol LabView uses to communicate with the device, and wrote a simple driver: http://www.ai3.uni-bayreuth.de/members/schuetz/niusb6501/

I hope it is useful for some people.

[J^T]

Marc:

Super!! Thank you!

Danke vielmals! 

--J^T