VISA READ from multiple buffers

[cocopa]

Hello,I'm trying to control my USB device through VISA.Since it has multiple buffers how can i specify in which of them to perform VISA read or write?

[Josh_L1]

Hi cocopa,

What device are you using? And what communication protocol is employed in this case? We need a little more information to properly support this issue. 

Regards,

Josh L.

[cocopa]

Hi Josh.

I'm using Cypress CyUSB and i want to perform bulk transfer.As i understand,it has multiple buffers which can be configured for bulk in or bulk out transfers and i want to define from which of them labview will read data from.When i tried to perform a control transfer,the endpoint buffer was by-default specified (endpoint buffer 0),but what about bulk transfers?

[Josh_L1]

Hi cocopa,

I found an example on bulk transfer from the Developer Zone.It's listed below for your reference. You can also find a similar example in the example finder under help.

http://zone.ni.com/devzone/cda/epd/p/id/3622#0requirements

Below is an article on the different USB data transfer protocols.

http://digital.ni.com/public.nsf/allkb/400D6EAB5CFE1C6B86257395005F5D48?OpenDocument

From what I understand, this will be a very specific application. Could you give us the spec sheet or any other relevant on this Cypress CyUSB device? If the device has multiple buffers, we will need to figure out how to the machine code is executed, and then how to translate that into LabVIEW code. You may need to contact the manufacturer.

On a final note, why are you trying to control which buffer you are reading from. If it's a latency issue, you might want to use interrupt data transfer. I've listed an article on that below.

http://digital.ni.com/public.nsf/allkb/457E3ADD7D2C1E7486257323007BAC0D?OpenDocument

Regards,

Josh L.