02-06-2009 08:50 AM
Hi, I am using the USB-6501 to interface with an LCD. The timing diagram for the LCD shows that one of the lines must be toggled for the purpose of writing to a register must be low for a maximum of 500ns (nano-seconds).
My question is: can I get this kind of speed out of the USB-6501? I am running the IO off of Windows, and, from the research that I have conducted, it seems that the fastest timing I can get is 1ms.
If I can't get this kind of speed from the USB-6501, are there any other IO devices from which I could? Or, is it just a Windows problem?
Thanks for your help in advance.
02-09-2009 03:46 PM
The USB-6501 can only do software timing (non deterministic) for digital input/output so you will not be able to reach the 500ns (or 2MHz) rate with this device (1ms was reasonable). To reach the rate you need you have to use a card with correlated DIO (Hardware timing). The link below shows some different devices that support correlated DIO. The High Speed digital I/O cards are available mostly in PCIe, PXIe, PCI but not in USB at this rate.
What Devices Other Than M Series Can Perform Correlated Digital I/O?
http://digital.ni.com/public.nsf/allkb/08F477754D0535CE862570020007142C
Filtered page to show only correlated DIO cards capable of 2MHz and higher
http://sine.ni.com/nifn/cds/view/main/p/sn/n20:8470,n4:7852/lang/en/nid/1036/ap/daq