Digital Output Problem

[cmora]

Hi James,

I am trying to do something similar to this example in a USB 6259 (M series), but I need a rate of 8 MHz.  Is that means that I need to put the number of samples to 8M and generate an array with that number of elements?

As the buffer size is limited to 1M, I do not understand very well how it should be configured.

I have tried creating an array with 1M elements and setting the number of samples and the buffer size to 1M, however it does not work up to 8 MHz. The maximum frequency I can get is 5 MHz.

The datasheet says that this DAQ can work up to 10MHz in the digital IO. Do you know if I am doing something wrong?

Regards,

cmora.

[jschwartz]

Hi cmora,

Could you explain a little more what tasks you are trying to perform with your 6259?  It sounds like  you are trying to output a pulse train at 8 MHz? Are you using any of the example programs?  You should be able to output 8 MHz.  You should start with the Correlated Dig Write with Counter.vi example program located in the Example Finder.  You can find this example within LabVIEW at Help >> Find Examples.  Then double click Hardware Input and Output >> DAQmx >> Digital Generation >> Correlated Dig Write with Counter.vi.  When you say that your can only get to 5 MHz, how did you test this?  Did you get errors above 5 MHz? 

[happyeveryday]

Hi, Jordan,

I have a similar question. I am using PCI 6602. The goal here is to get continuous 1MHz square wave output from DIO1~32 sequentially controlled by LabVIEW.  I used Ctr0 to generate a 2MHz clock and used Ctr0InternalOutput as sample clock of DIO1~32. I attached the code and screeshots as follows. But when I run it I got an error -200077 (you have requested: sample clock; you can request: on demand). It looks like PCI 6602 doesn't support hardware timing. Is that true? Where can I find this? If it is true, how can I avoid this and get what I want? Thanks!

Yi

Version: LabVIEW 8.2

hardware: PCI 6602

[happyeveryday]

Forgot to say. The code is working on PCIe 6251. But I need 32 DIO which PCIe 6251 doesn't have.

Yi

[John_P1]

Please see my post here.  The 6602 unfortunately does not support clocked digital waveform generation.

If you need 32 clocked digital lines then I would suggest either the PCI 6224, PCI 6254, PCIe 6323, PCIe 6353, or PCIe 6535.

Best Regards,