higher throughput with 6052

[honeydewsan]

I need to program using CVI, the digital IO lines of PCI-6052 at a speed of 50 kHz. Is there anyway to use the onboard timer of 20 MHz? I understand that PC timer has only a resolution of 1 ms, and thus not usable. I am using the easyIO instructions like WriteToDigitalLine.

[Russell]

Unfortunately, the DIO lines on the PCI-6052E are only static. They cannot perform hardware-timed I/O. For some, a software-timed loop is sufficient, but I see that this is not possible in your case.

There are other Multifunction DAQ boards that do support strobed DIO. The PCI-6025E is a 12-bit board that contains an 8255 chip that can perform handshaking I/O. On the other hand, the NI PCI-6120 is a simultaneous sampling 16-bit board that supports strobed I/O on it's digital lines.

I hope this helps!

Russell
Applications Engineer
National Instruments
http://www.ni.com/support

[honeydewsan]

Sorry that my question was misleading. I am trying to use PCI-DIO-96 at first, to switch digital lines at high rates than 1 ms, but it was not successful. This was due to 1ms resolution of PC timer.
I thought of using the digital lines on PCI-6052E because it has an onboard timer of 20 MHz. It could generate high speed pulses at MHz rates on counter-out lines but I need to switch the digital lines at faster than 10 us on the digital I/O lines instead, using CVI easyio instructions like WriteToDigitalLine.
The cards PCI-6025E and PCI-6120 are daq cards, but my application is not analog data acquisition but mainly digital i/o , for example, implementing 3 line serial communication with a clock and switching control lines at higher speed than 10 us.
I am
considering to use PCI-6534 because it has 32 bit high speed digital lines. Can I use the card to generate digital switching I/O control with instructions like WriteToDigitalLine? And how can I implement the timing for reading and writing the I/O lines since the PC timer is not usable?
Thanks a lot!

[Russell]

I see. I only suggested those analog boards because I noticed you were already using a 6052E and just assumend you would need analog functionality as well.

So at the rate you mentioned, your best bet is going to be a 653x like you suggested. Now, the PCI-6533 is the same as the PCI-6534 just without the extra onboard memory. A PCI-6533 would probably work for you just as well. In order to get the DIO rates you want, you will have to do a buffered output using DIG_Block_Out() for example. You can also have this output synchronized with one of the counters on your 6052E using a RTSI cable. The 660x counter board connected with a 653x is a one common combination for this type of application, but as long as you don't need more than 2 counters, you
can probably use the 6052E that you already have. I don't think we have many RTSI synchronization examples in CVI, but just look at the Select_Signal() function for the 6052E or counter board and RTSI_Conn(), RTSI_Disconn(), and RTSI_Clear for the 6533 board.

Let me know if you have any questions.

Russell
Applications Engineer
National Instruments
http://www.ni.com/support