I have an application that requires some very high resolution data reading from a PCIe-6612 card (or other, if this card is insufficient). I have done high speed analog before but not high speed counter, and not with a dedicated counter card. I want to make sure I'm reading the spec sheet right.
The application involves edge counting of a very fast source and reading out the data at very high rates. For example, there might be a nominally 10 MHz edge source, and he wants to read the number of edges at 1 MHz to see the actual number of pulses in each 1 ms window.
The datasheet (here) mentions a DI Sample Clock frequency of 0-10 MHz in the "Waveform DIO Functionality" section. I think I follow, but am not completely sure due to the nomenclature (it refers to DI/DO, but this is a counter card so I want to make sure I'm interpreting right).
-I assume "Waveform DIO" refers to the ability to read the "Number of samples" value from a given counter, correct? (i.e., I have counter 0 counting edges in task A, and can use task B to read the edge count at a rate of 0 to 10 MHz, presumably using ctr 1 as my sample clock)
-The DI FIFO is 255 samples. What exactly does this value tell me? I can't tell what that number means from any documentation I could find. I was pretty sure DAQmx sets up a DMA to another RAM buffer, which obfuscates this number, right? As long as I set up the right size buffer in LabVIEW before I read, and assuming the bus isn't getting overwhelmed, I can call DAQmx Read at a fairly leisurely pace (say every 100 ms, obtaining 10kS each read).
Like I said, I've done all of this before with multifunction IO cards, but not with the dedicated counter cards, and I'm not quite sure how to read the DI FIFO.
Thanks for any tips you can give.