Can I control the sampling action of NI5102 USB by input a controlled scan clock

[feiyn]

I want to acquire a waveform of 100us at 20MS/s sample rate, and this must be done repetitively 30 times per second. But unfortunately, my 5102USB can only do 10 times per second. Then I try to program my 5102 to acquire 30 records in 1 second without softwere interference, again it dose not support. I notice that 5102's scan clock input is different from other scopes, it is direcly used to control the sample, so can I input from this terminal a 20MHz clock for 100 us and then 1KHz for the following 3ms and again 20MHz for 100us.....If it works, I can use the memory on board to store the 30 records in one second.

Thank you for your help

[Mike_T]

Feiyn,
You have reached some of the limitations of the board. The 5102 is not double buffered so you can't do continous sample and retreival. It also doesn't support multiple records. You will need to reconfigure the board each time, which has a certain overhead.
You can use the PFI pin to route in a external clock. NI-SCOPE function calls don't support the use of an external clock. You will need to use NI-DAQ function calls. I found a couple examples in the NI-Developer Zone @ Keywords Search: 5102 external clock

Another solution would be to use a 5112 Scope card which supports continuous acquisition
and multiple records. The disadvantage is that it only comes in the PCI and PXI bus form facter.


Good luck,
Mike Taylor

Message Edited by Molly K on 02-18-2005 11:16 PM

[Mike_T]

Feiyn,
One minor correction. You can use an external clock with the 5102 in NI-SCOPE. The way that you do this is to configure the board as a slave then set the clock synch pulse source to external. Then set the input clock source to none. On the 5102 thclock synch pulse source is the input for the board clock. If you look at the 5102 synchronous example in LabVIEW and look at the slave thread you will see the sequence of function calls needed.

Good Luck,
Mike Taylor