Which DAQ Board for 3 pulse train outputs?

[OCE]

I've been tasked with creating a test device capable of outputting three different (and configurable via front panel 0-50Hz TTL) pulse trains. I have a USB-6501 but it does not have any pulse output capable counters or analog outputs. Consequently I've been trying to achieve my goal in software. I have been able to create multiple pulse outputs, but there are very inaccurate. 

My real question: which DAQ board can I use to do this? Do I need three counters? Or do I simply need more analog outputs? I could just be sending a square wave to an analog output, right?

Message Edited by OCE on 06-10-2010 08:49 AM

[John_P1]

Hi OCE,

The counters will be able to hit a higher resolution of frequencies since they can use a faster timebase than the sample clock for a DO or AO task.  If you had a board with HW-timed DO (or AO) you could still get good results--the programming wouldn't be quite as strightforward as you would have to build the waveform in software.  You might want to double-check AO settling time requirements if you go with AO.

Having said this, the hardware recommendation is going to depend on what form-factor you require:

PCIe:  63xx:  All of these boards have 4 counters that utilize a 100 MHz timebase.  The boards also support clocked Digital Outputs.  The first board in the X Series line is the 6320.  

 

PCI:   6601:  Has 4 counters that utilize a 20 MHz timebase.  Does not have any analog or clocked digital lines.

62xx:   Only has 2 counters.  However, these boards support clocked Digital Outputs at up to 1 MHz on 622x and 10 MHz on 625x.

 

USB:  62xx:  Same as above--however, be aware that the 621x bus-powered devices do not support clocked digital outputs.  They do have 2 Counter Outputs and some (like the 6211) have 2 clocked analog outputs.  The 10 MHz update rate on DO isn't achievable on the USB 625x due to USB bandwidth limitations, but you may regenerate from the on-board FIFO at this rate.

 

Best Regards,

John

Message Edited by John P on 06-10-2010 12:40 PM